Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)appli...Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.展开更多
Due to climate change, extreme heat stress events have become more frequent, adversely affecting rice yield and grain quality. The accumulation and translocation of dry matter and nitrogen substances are essential for...Due to climate change, extreme heat stress events have become more frequent, adversely affecting rice yield and grain quality. The accumulation and translocation of dry matter and nitrogen substances are essential for rice yield and grain quality. To assess the impact of high temperature stress(HTS) at the early panicle initiation(EPI) stage on the accumulation, transportation, and distribution of dry matter and nitrogen substances in various organs of rice, as well as the resulting effects on rice yield and grain quality, pot experiments were conducted using an indica rice cultivar Yangdao 6(YD6) and a japonica rice cultivar Jinxiangyu 1(JXY1) under both normal temperature(32 ℃/26 ℃) and high temperature(38 ℃/29 ℃) conditions. The results indicated that exposure to HTS at the EPI stage significantly decreased rice yield by reducing spikelet number per panicle, grain-filling rate, and grain weight. However, it improved the nutritional quality of rice grains by increasing protein and amylose contents. The reduction in nitrogen and dry matter accumulation accounted for the changes in spikelet number per panicle, grain-filling rate, and grain size. Under HTS, the decrease in nitrogen accumulation accompanied by the reduction in dry matter may be due to the down-regulation of leaf net photosynthesis and senescence, as evidenced by the decrease in nitrogen content. Furthermore, the decrease in sink size limited the translocation of dry matter and nitrogen substances to grains, which was closely related to the reduction in grain weight and the deterioration of grain quality. These findings significantly contribute to our understanding of the mechanisms of HTS on grain yield and quality formation from the perspective of dry matter and nitrogen accumulation and translocation. Further efforts are needed to improve the adaptability of rice varieties to climate change in the near future.展开更多
High temperature(HT)during grain filling is one of the most important environmental factors limiting maize yield and grain quality.Nitrogen(N)fertilizer is essential for maintaining normal plant growth and defense aga...High temperature(HT)during grain filling is one of the most important environmental factors limiting maize yield and grain quality.Nitrogen(N)fertilizer is essential for maintaining normal plant growth and defense against environmental stresses.The effects of three N rates and two temperature regimes on the grain yield and quality of fresh waxy maize were studied using the hybrids Suyunuo 5(SYN5)and Yunuo 7(YN7)as materials.N application rates were 1.5,4.5,and 7.5 g plant-1,representing low,moderate,and high N levels(LN,MN,and HN,respectively).Mean day/night temperatures during the grain filling of spring-and summer-sown plants were 27.6/21.0°C and 28.6/20.0°C for ambient temperature(AT)and 35/21.0°C and 35/20.0°C for HT,respectively.On average,HT reduced kernel number,weight,yield,and moisture content by 29.8%,17.9%,38.7%,and 3.3%,respectively.Kernel number,weight,yield,moisture,and starch contents were highest under MN among the three N rates under both temperature regimes.HT reduced grain starch content at all N levels.HT increased grain protein content,which gradually increased with N rate.Mean starch granule size under MN was larger(10.9μm)than that under LN and HN(both 10.4μm)at AT.However,the mean size of starch granules was higher under LN(11.7μm)and lower under MN(11.2μm)at HT.Iodine binding capacity(IBC)was lowest under MN and highest under HN among the three N levels under both temperature regimes.In general,IBC at all N rates was increased by HT.Peak viscosity(PV)was gradually reduced with increasing N rate at AT.In comparison with LN,PV was increased by MN and decreased by HN at HT.Retrogradation percentage gradually increased with N rate at AT,but was lowest under MN among the three N rates at HT.LN+AT and MN+HT produced grain with high pasting viscosity and low retrogradation tendency.MN application could alleviate the negative effects of HT on the grain yield and quality of fresh waxy maize.展开更多
A bentonite-humic acid(B-HA) mixture added to degraded soils may improve soil physical and hydraulic properties, due to effects such as improved soil structure and increased water and nutrient retention, but its effec...A bentonite-humic acid(B-HA) mixture added to degraded soils may improve soil physical and hydraulic properties, due to effects such as improved soil structure and increased water and nutrient retention, but its effect on soil physicochemical and biological properties, and grain quality is largely unknown. The effect of B-HA, added at 30 Mg ha^(-1), was studied at 1,3, 5 and 7 years after its addition to a degraded sandy soil in a semi-arid region of China. The addition of B-HA significantly increased water-filled pore space and soil organic carbon, especially at 3 to 5 years after its soil addition to the soil. Amending the sandy soil with B-HA also increased the content of microbial biomass(MB)-carbon,-nitrogen and-phosphorus, and the activities of urease, invertase, catalase and alkaline phosphatase. The significant effect of maize(Zea mays L.) growth stage on soil MB and enzyme activities accounted for 58 and 84% of their total variation, respectively. In comparison, B-HA accounted for 8% of the total variability for each of the same two variables. B-HA significantly enhanced soil properties and the uptake of N and P by maize in semi-arid areas. The use of B-HA product would be an effective management strategy to reclaim degraded sandy soils and foster sustainable agriculture production in northeast China and regions of the world with similar soils and climate.展开更多
Relationship between eating quality (EQ) andphysico-chemical properties of 78 high grainquality rice varieties, 45 indica and 33 japoni-ca, were studied in 1995. The samples werecollected from different rice growing r...Relationship between eating quality (EQ) andphysico-chemical properties of 78 high grainquality rice varieties, 45 indica and 33 japoni-ca, were studied in 1995. The samples werecollected from different rice growing regions in20 provinces. The physico-chemical proper-ties, including grain length (GL), length towidth ratio (L/W), chalky grain rate (CG),chalkiness (CH), translucency (TR), gela-tinization temperature (GT, measured by alka-li spreading value), gel consistency (GC),amylase content (AC), and protein content(PC) were measured according to the展开更多
Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw bur...Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw burial(NSB),with light straw burial of 300 kg/hm^(2)(LSB)and dense straw burial of 800 kg/hm^(2)(DSB),as well as three AWD regimes:alternate wetting/moderate drying(AWMD),alternate wetting/severe drying(AWSD)and alternate wetting/critical drying(AWCD).The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD regime.The AWMD×DSB treatment resulted in the highest yield,brown rice rate,milled rice rate,amylose content and protein content.Conversely,the AWCD×NSB treatment led to the lowest yield,brown rice rate,milled rice rate,amylose content and protein content.The active absorption area and nitrate reductase activity of roots were higher in the AWMD×DSB treatment than those in the AWCD×NSB treatment,as the former increased organic carbon and nitrogen contents in the rhizosphere,whereas the latter reduced their availability.Total soluble protein content and glutamine synthetase activity were greater in the AWMD×DSB treatment than those in the AWCD×NSB treatment.The activities of superoxide dismutase and catalase were higher in the AWMD×DSB treatment compared with the AWCD×NSB treatment,leading to the amelioration of oxidative cell injury,as shown by a lower malonaldehyde level.This study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field,followed by deep tillage to improve soil quality and mitigate the drought stress cycles of AWD.This approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.展开更多
Epoxiconazole is a triazole compound.However,the effects of epoxiconazole on crop productivity and quality were rarely reported.In this study,we investigated the effects of epoxiconazole application on yield formation...Epoxiconazole is a triazole compound.However,the effects of epoxiconazole on crop productivity and quality were rarely reported.In this study,we investigated the effects of epoxiconazole application on yield formation,grain quality attributes,and 2-acetyl-1-pyrroline(2-AP)content in fragrant rice.A three-year field experiment was carried out with a fragrant rice variety,Meixiangzhan 2.At the heading stage,0,0.02,0.04,0.08,0.16 and 0.32 g/L epoxiconazole solutions were foliar applied to fragrant rice plants,respectively.The results showed that epoxiconazole application significantly increased grain yield,seed-setting rate and 1000-grain weight.Chlorophyll content and net photosynthetic rate of fragrant rice during the grain-filling stage significantly increased due to epoxiconazole application.Foliar application of epoxiconazole at 0.08 g/L increased grain protein content and decreased both chalky rice rate and chalkiness area ratio of fragrant rice.Epoxiconazole also substantially increased grain 2-AP content by inducing the regulation in contents of related synthetic precursors,including proline,pyrroline-5-carboxylic acid,Δ1-pyrroline and methylglyoxal.Overall,foliar application of epoxiconazole could be used for the improvement in grain yield,grain quality and 2-AP content in fragrant rice production when applied concentration at 0.08-0.32 g/L.Our findings provided the new roles of epoxiconazole in crop production.展开更多
Fragrant rice is popular for the good grain quality and special aroma.The present study conducted a field experiment to investigate the effects of ultrasonic seed treatment on grain yield,quality characters,physiologi...Fragrant rice is popular for the good grain quality and special aroma.The present study conducted a field experiment to investigate the effects of ultrasonic seed treatment on grain yield,quality characters,physiological properties and aroma biosynthesis of different fragrant rice genotypes.The seeds of three fragrant rice genotypes were exposed to 1 min of ultrasonic vibration and then cultivated in paddy field.The results of present study showed that ultrasonic seed treatment increased grain yield of all fragrant rice genotypes but the responses of yield formation to ultrasonic were varied with different genotypes.Compared with control,ultrasonic seed treatment increased grain 2-acetyl-1-pyrroline(2-AP,the key component of fragrant rice aroma)content by 13.40%–44.88%.Ultrasonic seed treatment also reduced the crude protein contents in grains.The head rice rate,rice length,chalky rice rate,and chalkiness degree were influenced by ultrasonic for one or two fragrant rice genotypes.The activities of peroxidase and superoxide dismutase were also enhanced due to ultrasonic seed treatment.In conclusion,ultrasonic seed treatment increased grain,regulated grain aroma and quality,and improved stress resistance of fragrant rice varieties.展开更多
[Objectives]The paper was to study the effects of different herbicides on weed control,agronomic characters and grain quality of Coix lacryma-jobi L.[Methods]Six commonly used herbicides were selected for the trial,in...[Objectives]The paper was to study the effects of different herbicides on weed control,agronomic characters and grain quality of Coix lacryma-jobi L.[Methods]Six commonly used herbicides were selected for the trial,including atrazine SC,butachlor SC,monosulfuron WP,MCPA-starane EC,clopyralid AS and tribenuron-methyl WP.[Results](i)Atrazine,butachlor and monosulfuron had no chemical injury to C.lacryma-jobi L.,while clopyralid caused slight chemical injury.(ii)The fresh weight control effects of atrazine,butachlor and monosulfuron on weeds increased first and then decreased.The initial control effect of MCPA-starane and clopyralid reached more than 90%;the control effect of monosulfuron increased gradually in the late stage,reaching 97%at 60 d post spraying,and the overall control effect was optimal.(iii)Compared with manual weeding,herbicides had no significant effect on plant height of C.lacryma-jobi L.However,compared with no weeding,other herbicides except tribenuron-methyl inhibited plant growth to a certain extent.Herbicides had different effects on main stem diameter,tiller number per plant and grain number per plant of C.lacryma-jobi L.(iv)Different herbicides had no significant effect on 100-grain weight,but had significant effect on yield.(v)Compared with manual weeding,atrazine,butachlor and clopyralid decreased the protein content of C.lacryma-jobi L.,and the use of atrazine,butachlor,monosulfuron,MCPA-starane and tribenuron-methyl decreased the fat content of C.lacryma-jobi L.;butachlor and MCPA-starane decreased the glycerol trioleate content of C.lacryma-jobi L.Compared with no weeding,chemical herbicides had no significant effect on the protein content,while atrazine decreased the fat content,and butachlor and MCPA-starane decreased the glycerol trioleate content of C.lacryma-jobi L.[Conclusions]The use of herbicides significantly increases crop yield compared with no weeding,but has an impact on agronomic characters and grain quality.展开更多
The objective of this research was to determine <span style="font-family:;" "="">the effect of genotype and growing environment, particularly weather, on grain quality traits of durum wh...The objective of this research was to determine <span style="font-family:;" "="">the effect of genotype and growing environment, particularly weather, on grain quality traits of durum wheat using nine genotypes (Alkabo, Carpio, Divide, Grenora, Joppa, Maier, Mountrail, Pierce, and Tioga) grown in four years (2012-2015) at six locations in North Dakota, USA. The results of this research indicated that grain test weight, 1000-kernel weight, protein content, kernel vitreousness, and falling number were affected more by environment than by genotype. However, genotypes within an environment differed in the magnitude of their response and this difference could be used to select genotypes in a breeding program to improve quality. For a given quality trait, the magnitude of the response reflects the stability of the trait to changes in the environment. In general, the quality of durum wheat grown in the northern plains of USA was favored by warm daytime temperature, low night temperature, and low relative humidity. Growing locations with high maximum air temperature and a high number of days with temperature ≥ 30°C had a positive effect on grain protein content and falling number, while a high number of days with night time temperature ≤ 13°C were ideal for 1000-kernel weight. Low rainfall and low relative humidity promoted a high falling number and vitreous kernel content. The results of this study suggested that genotypes could be selected based on their overall quality and their stability across environments. Trait stability could be an important consideration when growers select genotypes for planting in their fields.</span>展开更多
The prevention of fungal spoilage is an essential consideration in wheat storage.Recent studies have revealed that volatile organic compounds(VOCs),possibly with natural fungicidal properties,could be produced from st...The prevention of fungal spoilage is an essential consideration in wheat storage.Recent studies have revealed that volatile organic compounds(VOCs),possibly with natural fungicidal properties,could be produced from stored wheat grains.In this study,the antifungal effect of hexanal,a main component of VOCs from stored wheat,against spoilage fungi on agar plate and in high-moisture wheat grains were investigated via the gas fumigation method.And the impact of hexanal fumigation on grain quality was evaluated through analysis of the malondialdehyde content,fatty acid values,germination percentages and vigor of 16%and 18%moisture wheat grains fumigated with 1.66,2.49,and 3.31 mmol/L hexanal vapor.The results of in vitro antifungal experiments on agar plates revealed that the minimum inhibitory concentration and minimum fungicidal(fatal)concentration of hexanal against the five fungi were 4–14 folds and 4–7 folds lower than those of propionic acid,respectively.The fungal spoilage of high-moisture wheat grains inoculated with pure fungal spores and with naturally occurring fungi could be completely inhibited by 1.66 mmol/L hexanal vapor.During 5-week storage of high-moisture wheat grains fumigated with 1.66,2.49,and 3.31 mmol/L hexanal vapor,the malondialdehyde content in high-moisture wheat grains did not change significantly in all samples,and fatty acid values were slightly higher in 18%moisture wheat than in 16%moisture wheat.The germination percentages and vigor of wheat samples decreased with increased hexanal vapor concentrations and moisture content.These results indicated that hexanal fumigation could be used as an alternative chemical control method to prevent the fungal spoilage of postharvest wheat.展开更多
Improving grain quality is a primary objective in contemporary rice breeding.Japanese modern rice breeding has developed two different types of rice,eating and sake-brewing rice,with different grain characteristics,in...Improving grain quality is a primary objective in contemporary rice breeding.Japanese modern rice breeding has developed two different types of rice,eating and sake-brewing rice,with different grain characteristics,indicating the selection of variant gene alleles during the breeding process.Given the critical importance of promptly and efficiently identifying genes selected in past breeding for future molecular breeding,we conducted genome scans for divergence,genome-wide association studies,and map-based cloning.Consequently,we successfully identified two genes,OsMnS and OsWOX9D,both contributing to rice grain traits.OsMnS encodes a mannan synthase that increases the white core frequency in the endosperm,a desirable trait for sake brewing but decreases the grain appearance quality.OsWOX9D encodes a grass-specific homeobox-containing transcription factor,which enhances grain width for better sake brewing.Furthermore,haplotype analysis revealed that their defective alleles were selected in East Asia,but not Europe,during modern improvement.In addition,our analyses indicate that a reduction in grain mannan content during African rice domestication may also be caused a defective OsMnS allele due to breeding selection.This study not only reveals the delicate balance between grain appearance quality and nutrition in rice but also provides a new strategy for isolating causal genes underlying complex traits,based on the concept of“breeding-assisted genomics”in plants.展开更多
Rice grain yield and quality are negatively impacted by high temperature stress.Irrigation water temperature significantly affects rice growth and development,thus influencing yield and quality.The role of cooler irri...Rice grain yield and quality are negatively impacted by high temperature stress.Irrigation water temperature significantly affects rice growth and development,thus influencing yield and quality.The role of cooler irrigation water in counteracting high temperature induced damages in rice grain yield and quality are not explored.Hence,in the present study two rice hybrids,Liangyoupeijiu(LYPJ)and IIyou 602(IIY602)were exposed to heat stress and irrigated with water having different temperatures in a splitsplit plot experimental design.The stress was imposed starting from heading until maturity under field-based heat tents,over two consecutive years.The maximum day temperature inside the heat tents was set at 38℃.For the irrigation treatments,two different water sources were used including belowground water with cooler water temperature and pond water with relatively higher water temperature.Daytime mean temperatures in the heat tents were increased by 1.2–2.0℃ across two years,while nighttime temperature remained similar at both within and outside the heat tents.Cooler belowground water irrigation did have little effect on air temperature at the canopy level but decreased soil temperature(0.2–1.4℃)especially under control.Heat stress significantly reduced grain yield(33%to 43%),panicles m^(-2)(9%to 10%),spikelets m^(-2)(15%to 22%),grain-filling percentage(13%to 26%)and 1000-grain weight(3%to 5%).Heat stress significantly increased chalkiness and protein content and decreased grain length and amylose content.Grain yield was negatively related to air temperature at the canopy level and soil temperature.Whereas grain quality parameters like chalkiness recorded a significantly positive association with both air and soil temperatures.Irrigating with cooler belowground water reduced the negative effect of heat stress on grain yield by 8.8%in LYPJ,while the same effect was not seen in IIY602,indicating cultivar differences in their response to irrigation water temperature.Our findings reveal that irrigating with cooler belowground water would not significantly mitigate yield loss or improve grain quality under realistic field condition.The outcome of this study adds to the scientific knowledge in understanding the interaction between heat stress and irrigation as a mitigation tool.Irrigation water temperature regulation at the rhizosphere was unable to counteract heat stress damages in rice and hence a more integrated management and genetic options at canopy levels should be explored in the future.展开更多
Breeding program strategies to develop novel short grain white rice varieties such as japonica(short grain)that introgress biotic stress resistance and high grain quality have been developed usingindica rice(Pin Kaset...Breeding program strategies to develop novel short grain white rice varieties such as japonica(short grain)that introgress biotic stress resistance and high grain quality have been developed usingindica rice(Pin Kaset+4 and Riceberry)for applications in japonica rice(Kashihikari)improvement.Fourbreeding lines showing promising agronomic performance with short grain and low amylose content(<20%)were obtained.In addition,sensory testing of these breeding lines showed high scores thatsimilar to Kashihikari.Two promising lines,KP48-1-5and KP48-1-9,which possessed a combination offour genes resistance to different biotic stresses(Bph3+TPS+Xa21+Pi-ta)and four genes for grainquality(G83+SSlla+w+badh2),were deveiaped using marker-assisted selection(MAS)with thepedigree method.The current study clearly illustrated the successful use of MAS in combining resistanceto multiple biotic stresses while maintaining a high yield potential and preferred grain quality.Moreover,the results indicated that this breeding program,which includes crossing temperate japonica with indica,can create novel short grain rice varieties adapted to a trapical environment like the japonica type.展开更多
The main goals of rice breeding nowadays include increasing yield,improving grain quality,and promoting complete mechanized production to save labor costs.Rice grain shape,specified by three dimensions,including grain...The main goals of rice breeding nowadays include increasing yield,improving grain quality,and promoting complete mechanized production to save labor costs.Rice grain shape,specified by three dimensions,including grain length,width and thickness,has a more precise meaning than grain size,contributing to grain appearance quality as well as grain weight and thus yield.Furthermore,the divergence of grain shape characters could be utilized in mechanical seed sorting in hybrid rice breeding systems,which has been succeeded in utilizing heterosis to achieve substantial increase in rice yield in the past decades.Several signaling pathways that regulate rice grain shape have been elucidated,including G protein signaling,ubiquitination-related pathway,mitogen-activated protein kinase signaling,phytohormone biosynthesis and signaling,micro RNA process,and some other transcriptional regulatory pathways and regulators.This review summarized the recent progress on molecular mechanisms underlying rice grain shape determination and the potential of major genes in future breeding applications.展开更多
Grain size is one of key agronomic traits associated with grain yield and grain quality. Both major quantitative trait loci GS3 and GL3.1 play a predominant role in negative regulation of grain size. In this study, a ...Grain size is one of key agronomic traits associated with grain yield and grain quality. Both major quantitative trait loci GS3 and GL3.1 play a predominant role in negative regulation of grain size. In this study, a CRISPR/Cas9-mediated multiplex genome editing system was used to simultaneously edit GS3 and GL3.1 in a typical japonica rice Nipponbare. In T1 generation, we found that gs3 formed slender grain with lower chalkiness percentage, while gs3gl3.1 produced larger grain with higher chalkiness percentage. In terms of other agronomic traits, flag leaf size, grain number and grain yield of both gs3 and gs3gl3.1 mutants were affected. It is noteworthy that gs3 and gs3gl3.1 mutants both led to dramatical reduction of grain number, thereby decreased grain yield. In conclusion, these results indicated that knockout of GS3 and GL3.1 could rapidly improve grain size, but probably have some negative influences on grain quality and grain yield.展开更多
Milling and appearance quality are important contributors to rice grain quality.Abundant genetic diversity and a suitable environment are crucial for rice improvement.In this study,we investigated the milling and appe...Milling and appearance quality are important contributors to rice grain quality.Abundant genetic diversity and a suitable environment are crucial for rice improvement.In this study,we investigated the milling and appearance quality-related traits in a panel of 200 japonica rice cultivars selected from Liaoning,Jilin and Heilongjiang provinces in Northeast China.Pedigree assessment and genetic diversity analysis indicated that cultivars from Jilin harbored the highest genetic diversity among the three geographic regions.An evaluation of grain quality indicated that cultivars from Liaoning showed superior milling quality,whereas cultivars from Heilongjiang tended to exhibit superior appearance quality.Single-and multi-locus genome-wide association studies(GWAS)were conducted to identify loci associated with milling and appearance quality-related traits.Ninety-nine significant single-nucleotide polymorphisms(SNPs)were detected.Three common SNPs were detected using the mixed linear model(MLM),mrMLM,and FASTmrMLM methods.Linkage disequilibrium decay was estimated and indicated three candidate regions(qBRR-1,qBRR-9 and qDEC-3)for further candidate gene analysis.More than 300 genes were located in these candidate regions.Gene Ontology(GO)analysis was performed to discover the potential candidate genes.Genetic diversity analysis of the candidate regions revealed that qBRR-9 may have been subject to strong selection during breeding.These results provide information that will be valuable for the improvement of grain quality in rice breeding.展开更多
Improving grain amino acid content of rice(Oryza sativa L.)is essential for the health of consumers.This study was conducted to identify the physiological processes that contribute to the higher grain amino acid conte...Improving grain amino acid content of rice(Oryza sativa L.)is essential for the health of consumers.This study was conducted to identify the physiological processes that contribute to the higher grain amino acid content in hybrid rice cultivar Lingliangyou 268 compared to Luliangyou 996.The results showed that total amino acid content in grains was 9%higher in Lingliangyou 268 than in Luliangyou 996.There was no significant difference in grain nitrogen(N)content between Lingliangyou 268 and Luliangyou 996,while ratio of amino acid to N was 6%higher in Lingliangyou 268 compared to Luliangyou 996.A total of 16 differentially expressed proteins related to amino acid metabolism(e.g.,erythronate-4-phosphate dehydrogenase domain containing protein)were identified in grains between Lingliangyou 268 and Luliangyou 996.The identified proteins were involved in 10 molecular functions.Six of the 10 defined functions were related to binding(heterocyclic compound binding,nucleoside phosphate binding,nucleotide binding,organic cyclic compound binding,protein binding,and small molecule binding)and the other 4 defined functions were catalytic activity,enzyme regulator activity,hydrolase activity,and transferase activity.These results indicate that the higher grain amino acid content in Lingliangyou 268 compared to Luliangyou 996 is attributed to increased efficiency of converting N to amino acid that results from altered expression of proteins related to amino acid metabolism.展开更多
In order to determine the most suitable sowing periods for maize in the cold area of Harbin City,the field test method was adopted.From 2018 to 2019,the main maize variety Xianyu 696 which was planted in Harbin City,H...In order to determine the most suitable sowing periods for maize in the cold area of Harbin City,the field test method was adopted.From 2018 to 2019,the main maize variety Xianyu 696 which was planted in Harbin City,Heilongjiang Province,was used as the test material for the six-sowing-period treatment experiments.The sowing period settings were as the followings:April 20(T1),April 24(T2),April 27(T3),May 4(T4),May 11(T5)and May 18(T6).In the experiment,the effects of different sowing periods on the growth and development,yields and quality of maize were studied.The results showed that the maize through T1 treatment had the longest growth period,the lowest height and the highest ear height,and the highest grain protein content.The maize through T6 treatment had the highest height and ear height,as well as the highest starch and oil content.And the grain crude fat,soluble protein,soluble sugar and the moisture content increased and then decreased with the delay of the sowing period.The maize through T4 treatment had the highest content of soluble protein.However,other quality indicators and the number of rows,the length of the bald tip,the number of grains per spike and the weight of 100 grains first increased and then decreased with the delay of the sowing period.The dry matter accumulation through T4 treatment was significantly higher than the ones through five treatments,and the 100-kernel weight and other ear-grain traits were the highest,the maizes through T4 treatment increased the yield by 21.54%compared with that through T1 treatment.Thus,the most suitable sowing period for the maize in the cold area of Harbin City was from May 4 to May 11.It provided technical supports for guiding maize planting in the cold area of Harbin City.展开更多
The performance of rice quality affects the market competitiveness of rice to a certain extent,and grain shape is an important factor for yield traits and appearance quality.The mapping and cloning of major rice grain...The performance of rice quality affects the market competitiveness of rice to a certain extent,and grain shape is an important factor for yield traits and appearance quality.The mapping and cloning of major rice grain type genes were briefly reviewed,and the utilization of related genes in breeding was prospected.展开更多
基金This work was financed by the National Natural Science Foundation of China(U20A2022,31901448 and 32001466)the Postdoctoral Research Foundation of China(2020M671628 and 2020M671629)+2 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions,China(19KJB210004)the Key Research and Development Program of Jiangsu Province,China(BE2019343)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.
基金supported by the Jiangsu Agriculture Science and Technology Innovation Fund,China(Grant No.CX(23)1035)the National Natural Science Foundation of China(Grant Nos.32201888,32071943,and 32272197)+2 种基金the Provincial Natural Science Foundation of Jiangsu,China(Grant No.BK20200923)the National Key Research and Development Program of China(Grant Nos.SQ 2022YFD1500402 and SQ2022YFD2300304)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘Due to climate change, extreme heat stress events have become more frequent, adversely affecting rice yield and grain quality. The accumulation and translocation of dry matter and nitrogen substances are essential for rice yield and grain quality. To assess the impact of high temperature stress(HTS) at the early panicle initiation(EPI) stage on the accumulation, transportation, and distribution of dry matter and nitrogen substances in various organs of rice, as well as the resulting effects on rice yield and grain quality, pot experiments were conducted using an indica rice cultivar Yangdao 6(YD6) and a japonica rice cultivar Jinxiangyu 1(JXY1) under both normal temperature(32 ℃/26 ℃) and high temperature(38 ℃/29 ℃) conditions. The results indicated that exposure to HTS at the EPI stage significantly decreased rice yield by reducing spikelet number per panicle, grain-filling rate, and grain weight. However, it improved the nutritional quality of rice grains by increasing protein and amylose contents. The reduction in nitrogen and dry matter accumulation accounted for the changes in spikelet number per panicle, grain-filling rate, and grain size. Under HTS, the decrease in nitrogen accumulation accompanied by the reduction in dry matter may be due to the down-regulation of leaf net photosynthesis and senescence, as evidenced by the decrease in nitrogen content. Furthermore, the decrease in sink size limited the translocation of dry matter and nitrogen substances to grains, which was closely related to the reduction in grain weight and the deterioration of grain quality. These findings significantly contribute to our understanding of the mechanisms of HTS on grain yield and quality formation from the perspective of dry matter and nitrogen accumulation and translocation. Further efforts are needed to improve the adaptability of rice varieties to climate change in the near future.
基金supported by the National Key Research and Development Program of China(2016YFD0300109,2018YFD0200703)the National Natural Science Foundation of China(31771709)+2 种基金Jiangsu Agriculture Science and Technology Innovation Fund(CX[19]3056)the Priority Academic Program Development of Jiangsu Higher Education InstitutionsHigh-end Talent Support Program of Yangzhou University。
文摘High temperature(HT)during grain filling is one of the most important environmental factors limiting maize yield and grain quality.Nitrogen(N)fertilizer is essential for maintaining normal plant growth and defense against environmental stresses.The effects of three N rates and two temperature regimes on the grain yield and quality of fresh waxy maize were studied using the hybrids Suyunuo 5(SYN5)and Yunuo 7(YN7)as materials.N application rates were 1.5,4.5,and 7.5 g plant-1,representing low,moderate,and high N levels(LN,MN,and HN,respectively).Mean day/night temperatures during the grain filling of spring-and summer-sown plants were 27.6/21.0°C and 28.6/20.0°C for ambient temperature(AT)and 35/21.0°C and 35/20.0°C for HT,respectively.On average,HT reduced kernel number,weight,yield,and moisture content by 29.8%,17.9%,38.7%,and 3.3%,respectively.Kernel number,weight,yield,moisture,and starch contents were highest under MN among the three N rates under both temperature regimes.HT reduced grain starch content at all N levels.HT increased grain protein content,which gradually increased with N rate.Mean starch granule size under MN was larger(10.9μm)than that under LN and HN(both 10.4μm)at AT.However,the mean size of starch granules was higher under LN(11.7μm)and lower under MN(11.2μm)at HT.Iodine binding capacity(IBC)was lowest under MN and highest under HN among the three N levels under both temperature regimes.In general,IBC at all N rates was increased by HT.Peak viscosity(PV)was gradually reduced with increasing N rate at AT.In comparison with LN,PV was increased by MN and decreased by HN at HT.Retrogradation percentage gradually increased with N rate at AT,but was lowest under MN among the three N rates at HT.LN+AT and MN+HT produced grain with high pasting viscosity and low retrogradation tendency.MN application could alleviate the negative effects of HT on the grain yield and quality of fresh waxy maize.
基金financial support provided by the National Special Fund for Agro-scientific Research in the Public Interest of China(201303126)Agricultural Science and Technology Achievements Transformation Demonstration of Production and Application Technology and Popularization of Sandy Soil Amendment,Inner Mongolia,China(sq2012eca400008)。
文摘A bentonite-humic acid(B-HA) mixture added to degraded soils may improve soil physical and hydraulic properties, due to effects such as improved soil structure and increased water and nutrient retention, but its effect on soil physicochemical and biological properties, and grain quality is largely unknown. The effect of B-HA, added at 30 Mg ha^(-1), was studied at 1,3, 5 and 7 years after its addition to a degraded sandy soil in a semi-arid region of China. The addition of B-HA significantly increased water-filled pore space and soil organic carbon, especially at 3 to 5 years after its soil addition to the soil. Amending the sandy soil with B-HA also increased the content of microbial biomass(MB)-carbon,-nitrogen and-phosphorus, and the activities of urease, invertase, catalase and alkaline phosphatase. The significant effect of maize(Zea mays L.) growth stage on soil MB and enzyme activities accounted for 58 and 84% of their total variation, respectively. In comparison, B-HA accounted for 8% of the total variability for each of the same two variables. B-HA significantly enhanced soil properties and the uptake of N and P by maize in semi-arid areas. The use of B-HA product would be an effective management strategy to reclaim degraded sandy soils and foster sustainable agriculture production in northeast China and regions of the world with similar soils and climate.
文摘Relationship between eating quality (EQ) andphysico-chemical properties of 78 high grainquality rice varieties, 45 indica and 33 japoni-ca, were studied in 1995. The samples werecollected from different rice growing regions in20 provinces. The physico-chemical proper-ties, including grain length (GL), length towidth ratio (L/W), chalky grain rate (CG),chalkiness (CH), translucency (TR), gela-tinization temperature (GT, measured by alka-li spreading value), gel consistency (GC),amylase content (AC), and protein content(PC) were measured according to the
基金supported by the Water Conservancy Science and Technology Project of Jiangsu Province,China(Grant Nos.2020049 and 2021055).
文摘Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw burial(NSB),with light straw burial of 300 kg/hm^(2)(LSB)and dense straw burial of 800 kg/hm^(2)(DSB),as well as three AWD regimes:alternate wetting/moderate drying(AWMD),alternate wetting/severe drying(AWSD)and alternate wetting/critical drying(AWCD).The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD regime.The AWMD×DSB treatment resulted in the highest yield,brown rice rate,milled rice rate,amylose content and protein content.Conversely,the AWCD×NSB treatment led to the lowest yield,brown rice rate,milled rice rate,amylose content and protein content.The active absorption area and nitrate reductase activity of roots were higher in the AWMD×DSB treatment than those in the AWCD×NSB treatment,as the former increased organic carbon and nitrogen contents in the rhizosphere,whereas the latter reduced their availability.Total soluble protein content and glutamine synthetase activity were greater in the AWMD×DSB treatment than those in the AWCD×NSB treatment.The activities of superoxide dismutase and catalase were higher in the AWMD×DSB treatment compared with the AWCD×NSB treatment,leading to the amelioration of oxidative cell injury,as shown by a lower malonaldehyde level.This study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field,followed by deep tillage to improve soil quality and mitigate the drought stress cycles of AWD.This approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.
基金This study was supported by the National Natural Science Foundation of China(Grant No.31971843)the Technology System of Modern Agricultural Industry in Guangdong(Grant No.2020KJ105)Guangzhou Science and Technology Project in China(Grant No.202103000075).
文摘Epoxiconazole is a triazole compound.However,the effects of epoxiconazole on crop productivity and quality were rarely reported.In this study,we investigated the effects of epoxiconazole application on yield formation,grain quality attributes,and 2-acetyl-1-pyrroline(2-AP)content in fragrant rice.A three-year field experiment was carried out with a fragrant rice variety,Meixiangzhan 2.At the heading stage,0,0.02,0.04,0.08,0.16 and 0.32 g/L epoxiconazole solutions were foliar applied to fragrant rice plants,respectively.The results showed that epoxiconazole application significantly increased grain yield,seed-setting rate and 1000-grain weight.Chlorophyll content and net photosynthetic rate of fragrant rice during the grain-filling stage significantly increased due to epoxiconazole application.Foliar application of epoxiconazole at 0.08 g/L increased grain protein content and decreased both chalky rice rate and chalkiness area ratio of fragrant rice.Epoxiconazole also substantially increased grain 2-AP content by inducing the regulation in contents of related synthetic precursors,including proline,pyrroline-5-carboxylic acid,Δ1-pyrroline and methylglyoxal.Overall,foliar application of epoxiconazole could be used for the improvement in grain yield,grain quality and 2-AP content in fragrant rice production when applied concentration at 0.08-0.32 g/L.Our findings provided the new roles of epoxiconazole in crop production.
基金supported by National Natural Science Foundation of China(31971843)The Technology System of Modern Agricultural Industry in Guangdong(2020KJ105)Guangzhou Science and Technology Project(202103000075).Xiangru Tang received the grants.
文摘Fragrant rice is popular for the good grain quality and special aroma.The present study conducted a field experiment to investigate the effects of ultrasonic seed treatment on grain yield,quality characters,physiological properties and aroma biosynthesis of different fragrant rice genotypes.The seeds of three fragrant rice genotypes were exposed to 1 min of ultrasonic vibration and then cultivated in paddy field.The results of present study showed that ultrasonic seed treatment increased grain yield of all fragrant rice genotypes but the responses of yield formation to ultrasonic were varied with different genotypes.Compared with control,ultrasonic seed treatment increased grain 2-acetyl-1-pyrroline(2-AP,the key component of fragrant rice aroma)content by 13.40%–44.88%.Ultrasonic seed treatment also reduced the crude protein contents in grains.The head rice rate,rice length,chalky rice rate,and chalkiness degree were influenced by ultrasonic for one or two fragrant rice genotypes.The activities of peroxidase and superoxide dismutase were also enhanced due to ultrasonic seed treatment.In conclusion,ultrasonic seed treatment increased grain,regulated grain aroma and quality,and improved stress resistance of fragrant rice varieties.
基金Key Technology R&D Program of Guizhou Province(QKHZC[2021]247)QKHZC[2018]2310。
文摘[Objectives]The paper was to study the effects of different herbicides on weed control,agronomic characters and grain quality of Coix lacryma-jobi L.[Methods]Six commonly used herbicides were selected for the trial,including atrazine SC,butachlor SC,monosulfuron WP,MCPA-starane EC,clopyralid AS and tribenuron-methyl WP.[Results](i)Atrazine,butachlor and monosulfuron had no chemical injury to C.lacryma-jobi L.,while clopyralid caused slight chemical injury.(ii)The fresh weight control effects of atrazine,butachlor and monosulfuron on weeds increased first and then decreased.The initial control effect of MCPA-starane and clopyralid reached more than 90%;the control effect of monosulfuron increased gradually in the late stage,reaching 97%at 60 d post spraying,and the overall control effect was optimal.(iii)Compared with manual weeding,herbicides had no significant effect on plant height of C.lacryma-jobi L.However,compared with no weeding,other herbicides except tribenuron-methyl inhibited plant growth to a certain extent.Herbicides had different effects on main stem diameter,tiller number per plant and grain number per plant of C.lacryma-jobi L.(iv)Different herbicides had no significant effect on 100-grain weight,but had significant effect on yield.(v)Compared with manual weeding,atrazine,butachlor and clopyralid decreased the protein content of C.lacryma-jobi L.,and the use of atrazine,butachlor,monosulfuron,MCPA-starane and tribenuron-methyl decreased the fat content of C.lacryma-jobi L.;butachlor and MCPA-starane decreased the glycerol trioleate content of C.lacryma-jobi L.Compared with no weeding,chemical herbicides had no significant effect on the protein content,while atrazine decreased the fat content,and butachlor and MCPA-starane decreased the glycerol trioleate content of C.lacryma-jobi L.[Conclusions]The use of herbicides significantly increases crop yield compared with no weeding,but has an impact on agronomic characters and grain quality.
文摘The objective of this research was to determine <span style="font-family:;" "="">the effect of genotype and growing environment, particularly weather, on grain quality traits of durum wheat using nine genotypes (Alkabo, Carpio, Divide, Grenora, Joppa, Maier, Mountrail, Pierce, and Tioga) grown in four years (2012-2015) at six locations in North Dakota, USA. The results of this research indicated that grain test weight, 1000-kernel weight, protein content, kernel vitreousness, and falling number were affected more by environment than by genotype. However, genotypes within an environment differed in the magnitude of their response and this difference could be used to select genotypes in a breeding program to improve quality. For a given quality trait, the magnitude of the response reflects the stability of the trait to changes in the environment. In general, the quality of durum wheat grown in the northern plains of USA was favored by warm daytime temperature, low night temperature, and low relative humidity. Growing locations with high maximum air temperature and a high number of days with temperature ≥ 30°C had a positive effect on grain protein content and falling number, while a high number of days with night time temperature ≤ 13°C were ideal for 1000-kernel weight. Low rainfall and low relative humidity promoted a high falling number and vitreous kernel content. The results of this study suggested that genotypes could be selected based on their overall quality and their stability across environments. Trait stability could be an important consideration when growers select genotypes for planting in their fields.</span>
基金supported by the NationalNatural Science Foundation of China(Project No.31772023)the National Key Research and Development Project of China(Project Nos.2017YFC1600903 and 2017YFD0401404)+1 种基金the National Key Research and Development Project of China(Project No.2019YFC1605303-04)the Scientific Research foundation of Henan University of Technology(Project No.2018RCJH14).
文摘The prevention of fungal spoilage is an essential consideration in wheat storage.Recent studies have revealed that volatile organic compounds(VOCs),possibly with natural fungicidal properties,could be produced from stored wheat grains.In this study,the antifungal effect of hexanal,a main component of VOCs from stored wheat,against spoilage fungi on agar plate and in high-moisture wheat grains were investigated via the gas fumigation method.And the impact of hexanal fumigation on grain quality was evaluated through analysis of the malondialdehyde content,fatty acid values,germination percentages and vigor of 16%and 18%moisture wheat grains fumigated with 1.66,2.49,and 3.31 mmol/L hexanal vapor.The results of in vitro antifungal experiments on agar plates revealed that the minimum inhibitory concentration and minimum fungicidal(fatal)concentration of hexanal against the five fungi were 4–14 folds and 4–7 folds lower than those of propionic acid,respectively.The fungal spoilage of high-moisture wheat grains inoculated with pure fungal spores and with naturally occurring fungi could be completely inhibited by 1.66 mmol/L hexanal vapor.During 5-week storage of high-moisture wheat grains fumigated with 1.66,2.49,and 3.31 mmol/L hexanal vapor,the malondialdehyde content in high-moisture wheat grains did not change significantly in all samples,and fatty acid values were slightly higher in 18%moisture wheat than in 16%moisture wheat.The germination percentages and vigor of wheat samples decreased with increased hexanal vapor concentrations and moisture content.These results indicated that hexanal fumigation could be used as an alternative chemical control method to prevent the fungal spoilage of postharvest wheat.
文摘Improving grain quality is a primary objective in contemporary rice breeding.Japanese modern rice breeding has developed two different types of rice,eating and sake-brewing rice,with different grain characteristics,indicating the selection of variant gene alleles during the breeding process.Given the critical importance of promptly and efficiently identifying genes selected in past breeding for future molecular breeding,we conducted genome scans for divergence,genome-wide association studies,and map-based cloning.Consequently,we successfully identified two genes,OsMnS and OsWOX9D,both contributing to rice grain traits.OsMnS encodes a mannan synthase that increases the white core frequency in the endosperm,a desirable trait for sake brewing but decreases the grain appearance quality.OsWOX9D encodes a grass-specific homeobox-containing transcription factor,which enhances grain width for better sake brewing.Furthermore,haplotype analysis revealed that their defective alleles were selected in East Asia,but not Europe,during modern improvement.In addition,our analyses indicate that a reduction in grain mannan content during African rice domestication may also be caused a defective OsMnS allele due to breeding selection.This study not only reveals the delicate balance between grain appearance quality and nutrition in rice but also provides a new strategy for isolating causal genes underlying complex traits,based on the concept of“breeding-assisted genomics”in plants.
基金provided by Science and Technology Plan Project of Hunan Province(2019RS1054)Open Research Fund of State Key Laboratory of Hybrid Rice provided by Hunan Hybrid Rice Research Center(2018KF05)+4 种基金Scientific Research Fund of Hunan Provincial Education Department(18B109)Scientific Research Funding for Crop Science(YXQN2018-6)Hundred Talents Program of the Hunan Provincethe grant support from Hong Kong Research Grants Council(GRF 12103219 and 12103220 and Ao E/M-403/16)a Scholarship from Hong Kong Scholars Program。
文摘Rice grain yield and quality are negatively impacted by high temperature stress.Irrigation water temperature significantly affects rice growth and development,thus influencing yield and quality.The role of cooler irrigation water in counteracting high temperature induced damages in rice grain yield and quality are not explored.Hence,in the present study two rice hybrids,Liangyoupeijiu(LYPJ)and IIyou 602(IIY602)were exposed to heat stress and irrigated with water having different temperatures in a splitsplit plot experimental design.The stress was imposed starting from heading until maturity under field-based heat tents,over two consecutive years.The maximum day temperature inside the heat tents was set at 38℃.For the irrigation treatments,two different water sources were used including belowground water with cooler water temperature and pond water with relatively higher water temperature.Daytime mean temperatures in the heat tents were increased by 1.2–2.0℃ across two years,while nighttime temperature remained similar at both within and outside the heat tents.Cooler belowground water irrigation did have little effect on air temperature at the canopy level but decreased soil temperature(0.2–1.4℃)especially under control.Heat stress significantly reduced grain yield(33%to 43%),panicles m^(-2)(9%to 10%),spikelets m^(-2)(15%to 22%),grain-filling percentage(13%to 26%)and 1000-grain weight(3%to 5%).Heat stress significantly increased chalkiness and protein content and decreased grain length and amylose content.Grain yield was negatively related to air temperature at the canopy level and soil temperature.Whereas grain quality parameters like chalkiness recorded a significantly positive association with both air and soil temperatures.Irrigating with cooler belowground water reduced the negative effect of heat stress on grain yield by 8.8%in LYPJ,while the same effect was not seen in IIY602,indicating cultivar differences in their response to irrigation water temperature.Our findings reveal that irrigating with cooler belowground water would not significantly mitigate yield loss or improve grain quality under realistic field condition.The outcome of this study adds to the scientific knowledge in understanding the interaction between heat stress and irrigation as a mitigation tool.Irrigation water temperature regulation at the rhizosphere was unable to counteract heat stress damages in rice and hence a more integrated management and genetic options at canopy levels should be explored in the future.
基金supported by the Tana Group International Co.Ltd.,Thailand(2015-2019).
文摘Breeding program strategies to develop novel short grain white rice varieties such as japonica(short grain)that introgress biotic stress resistance and high grain quality have been developed usingindica rice(Pin Kaset+4 and Riceberry)for applications in japonica rice(Kashihikari)improvement.Fourbreeding lines showing promising agronomic performance with short grain and low amylose content(<20%)were obtained.In addition,sensory testing of these breeding lines showed high scores thatsimilar to Kashihikari.Two promising lines,KP48-1-5and KP48-1-9,which possessed a combination offour genes resistance to different biotic stresses(Bph3+TPS+Xa21+Pi-ta)and four genes for grainquality(G83+SSlla+w+badh2),were deveiaped using marker-assisted selection(MAS)with thepedigree method.The current study clearly illustrated the successful use of MAS in combining resistanceto multiple biotic stresses while maintaining a high yield potential and preferred grain quality.Moreover,the results indicated that this breeding program,which includes crossing temperate japonica with indica,can create novel short grain rice varieties adapted to a trapical environment like the japonica type.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.32100257,32172078,31871599 and 31901528)Hunan Science and Technology Innovation Program,China(Grant Nos.2021NK1001,2021NK1003 and 2021NK1011)+1 种基金Key Research and Development,Projects in Hunan Province,China(Grant No.2020NK2054)the Open Programs of the State Key Laboratory of Hybrid Rice,Changsha,China(Grant No.2020KF03)。
文摘The main goals of rice breeding nowadays include increasing yield,improving grain quality,and promoting complete mechanized production to save labor costs.Rice grain shape,specified by three dimensions,including grain length,width and thickness,has a more precise meaning than grain size,contributing to grain appearance quality as well as grain weight and thus yield.Furthermore,the divergence of grain shape characters could be utilized in mechanical seed sorting in hybrid rice breeding systems,which has been succeeded in utilizing heterosis to achieve substantial increase in rice yield in the past decades.Several signaling pathways that regulate rice grain shape have been elucidated,including G protein signaling,ubiquitination-related pathway,mitogen-activated protein kinase signaling,phytohormone biosynthesis and signaling,micro RNA process,and some other transcriptional regulatory pathways and regulators.This review summarized the recent progress on molecular mechanisms underlying rice grain shape determination and the potential of major genes in future breeding applications.
基金supported by the National Nature Science Foundation of China(Grant Nos.31521064 and 31961143016)Technological Innovation Project of Chinese Academy of Agricultural Sciences(Grant No.CAASASTIP-2013-CNRRI)+2 种基金Major Transgenic Projects of China(Grant No.2016ZX08001-002)National Key Research and Development Program(Grant No.2016YFD0101801)the Natural Science Foundation of Innovation Research Group(Grant No.31521064)。
文摘Grain size is one of key agronomic traits associated with grain yield and grain quality. Both major quantitative trait loci GS3 and GL3.1 play a predominant role in negative regulation of grain size. In this study, a CRISPR/Cas9-mediated multiplex genome editing system was used to simultaneously edit GS3 and GL3.1 in a typical japonica rice Nipponbare. In T1 generation, we found that gs3 formed slender grain with lower chalkiness percentage, while gs3gl3.1 produced larger grain with higher chalkiness percentage. In terms of other agronomic traits, flag leaf size, grain number and grain yield of both gs3 and gs3gl3.1 mutants were affected. It is noteworthy that gs3 and gs3gl3.1 mutants both led to dramatical reduction of grain number, thereby decreased grain yield. In conclusion, these results indicated that knockout of GS3 and GL3.1 could rapidly improve grain size, but probably have some negative influences on grain quality and grain yield.
基金funded by the National Key Research and Development Program of China(2016YFD0100902–07)the Central Public-interest Scientific Institution Basal Research Fund,China(CPSIBRF-CNRRI-202101)the Chinese Academy of Agricultural Sciences(CAASASTIP-201X-CNRRI)
文摘Milling and appearance quality are important contributors to rice grain quality.Abundant genetic diversity and a suitable environment are crucial for rice improvement.In this study,we investigated the milling and appearance quality-related traits in a panel of 200 japonica rice cultivars selected from Liaoning,Jilin and Heilongjiang provinces in Northeast China.Pedigree assessment and genetic diversity analysis indicated that cultivars from Jilin harbored the highest genetic diversity among the three geographic regions.An evaluation of grain quality indicated that cultivars from Liaoning showed superior milling quality,whereas cultivars from Heilongjiang tended to exhibit superior appearance quality.Single-and multi-locus genome-wide association studies(GWAS)were conducted to identify loci associated with milling and appearance quality-related traits.Ninety-nine significant single-nucleotide polymorphisms(SNPs)were detected.Three common SNPs were detected using the mixed linear model(MLM),mrMLM,and FASTmrMLM methods.Linkage disequilibrium decay was estimated and indicated three candidate regions(qBRR-1,qBRR-9 and qDEC-3)for further candidate gene analysis.More than 300 genes were located in these candidate regions.Gene Ontology(GO)analysis was performed to discover the potential candidate genes.Genetic diversity analysis of the candidate regions revealed that qBRR-9 may have been subject to strong selection during breeding.These results provide information that will be valuable for the improvement of grain quality in rice breeding.
文摘Improving grain amino acid content of rice(Oryza sativa L.)is essential for the health of consumers.This study was conducted to identify the physiological processes that contribute to the higher grain amino acid content in hybrid rice cultivar Lingliangyou 268 compared to Luliangyou 996.The results showed that total amino acid content in grains was 9%higher in Lingliangyou 268 than in Luliangyou 996.There was no significant difference in grain nitrogen(N)content between Lingliangyou 268 and Luliangyou 996,while ratio of amino acid to N was 6%higher in Lingliangyou 268 compared to Luliangyou 996.A total of 16 differentially expressed proteins related to amino acid metabolism(e.g.,erythronate-4-phosphate dehydrogenase domain containing protein)were identified in grains between Lingliangyou 268 and Luliangyou 996.The identified proteins were involved in 10 molecular functions.Six of the 10 defined functions were related to binding(heterocyclic compound binding,nucleoside phosphate binding,nucleotide binding,organic cyclic compound binding,protein binding,and small molecule binding)and the other 4 defined functions were catalytic activity,enzyme regulator activity,hydrolase activity,and transferase activity.These results indicate that the higher grain amino acid content in Lingliangyou 268 compared to Luliangyou 996 is attributed to increased efficiency of converting N to amino acid that results from altered expression of proteins related to amino acid metabolism.
基金Supported by"Thirteenth Five-Year"Key Research and Development Project Sub-project"Integration and Demonstration of Spring maize Solar and Hot Water Resources Utilization Technology in Humid Areas of Heilongjiang Province"(2018YFD0300103-1)。
文摘In order to determine the most suitable sowing periods for maize in the cold area of Harbin City,the field test method was adopted.From 2018 to 2019,the main maize variety Xianyu 696 which was planted in Harbin City,Heilongjiang Province,was used as the test material for the six-sowing-period treatment experiments.The sowing period settings were as the followings:April 20(T1),April 24(T2),April 27(T3),May 4(T4),May 11(T5)and May 18(T6).In the experiment,the effects of different sowing periods on the growth and development,yields and quality of maize were studied.The results showed that the maize through T1 treatment had the longest growth period,the lowest height and the highest ear height,and the highest grain protein content.The maize through T6 treatment had the highest height and ear height,as well as the highest starch and oil content.And the grain crude fat,soluble protein,soluble sugar and the moisture content increased and then decreased with the delay of the sowing period.The maize through T4 treatment had the highest content of soluble protein.However,other quality indicators and the number of rows,the length of the bald tip,the number of grains per spike and the weight of 100 grains first increased and then decreased with the delay of the sowing period.The dry matter accumulation through T4 treatment was significantly higher than the ones through five treatments,and the 100-kernel weight and other ear-grain traits were the highest,the maizes through T4 treatment increased the yield by 21.54%compared with that through T1 treatment.Thus,the most suitable sowing period for the maize in the cold area of Harbin City was from May 4 to May 11.It provided technical supports for guiding maize planting in the cold area of Harbin City.
文摘The performance of rice quality affects the market competitiveness of rice to a certain extent,and grain shape is an important factor for yield traits and appearance quality.The mapping and cloning of major rice grain type genes were briefly reviewed,and the utilization of related genes in breeding was prospected.
