Drought stress severely impairs common bean production.For facilitating drought-resistance breeding in common bean,molecular markers were identified in a genome-wide level marker–trait association study.A panel of 21...Drought stress severely impairs common bean production.For facilitating drought-resistance breeding in common bean,molecular markers were identified in a genome-wide level marker–trait association study.A panel of 210 common bean accessions showed large variation in 11 agronomic traits at the adult stage(plant height,pod number per plant,seed number per pod,seed number per plant,seed yield per plant,pod length,harvest index,pod harvest index,days to maturity,hundred-seed weight,and seed yield)under two water conditions.The coefficient of variation ranged from 6.21% for pod harvest index to51.00% for seed number per plant under well-watered conditions,and from 4.05% for days to maturity to 40.72% for seed number per plant under drought stress.In a genome-wide association study,119quantitative-trait loci were associated with drought resistance,including 41 adjacent to known loci.Among these loci,12 were found to be associated with at least two traits.Three major loci were identified at Pv01 and Pv02.A set of candidate genes were found that encode MYBs,AREBs,WKRYs,and protein kinases.These results reveal promising alleles that control drought resistance,shedding light on the genetic basis of drought resistance and accelerating future efforts for drought resistance improvement in common bean.展开更多
Sweetpotato(Ipomoea batatas(L.)Lam.)is a widely grown food crop especially in developing countries.Increasing storage-root yield and dry-matter content has been the main breeding objective of the crop,and DNA marker-a...Sweetpotato(Ipomoea batatas(L.)Lam.)is a widely grown food crop especially in developing countries.Increasing storage-root yield and dry-matter content has been the main breeding objective of the crop,and DNA marker-assisted breeding is needed for this purpose.In this study,using a mapping population of 500 F1 individuals from a cross between Xushu 18(female)and Xu 781(male),we constructed a highdensity genetic linkage map of sweetpotato using 601 simple-sequence repeat(SSR)primer pairs.The Xushu 18 map contained 90 linkage groups with 5547 SSR markers and spanned 18,263.5 cM,and the Xu 781 map contained 90 linkage groups with 4599 SSR markers and spanned 18,043.7 cM,representing the highest genome coverage yet reported for sweetpotato.We identified 33 QTL for storage-root yield and 16 QTL for dry-matter content,explaining respectively 6.5%–47.5%and 3.2%–18.9%of variation.These results provide a foundation for fine-mapping and cloning of QTL and for marker-assisted breeding in sweetpotato.展开更多
Grain size, determined by grain length, grain width and grain thickness, is associated with grain yield and quality. Many genes controlling grain size were cloned and their related regulatory mechanisms were clearly c...Grain size, determined by grain length, grain width and grain thickness, is associated with grain yield and quality. Many genes controlling grain size were cloned and their related regulatory mechanisms were clearly clarified. However, whether these genes can be directly introduced into japonica rice for grain size improvement is unknown.展开更多
Grain size is controlled by many QTLs and/or genes.Despite intensive study,the genetic interactions between these QTLs/genes remain largely unclear.We previously found that the japonica large-grain rice cultivar TD70 ...Grain size is controlled by many QTLs and/or genes.Despite intensive study,the genetic interactions between these QTLs/genes remain largely unclear.We previously found that the japonica large-grain rice cultivar TD70 with 1000-grain weight of 68.6 g carries superior alleles at the loci GW2,GS3,qGL3,GS5 and GW8,all of which are known to control grain size,while the indica rice variety Kasalath with 1000-grain weight of 19.1 g has normal alleles at these loci.展开更多
Aleurone forms the outermost layer of the rice endosperm and plays a critical role in apoplastic nutrient uptake during endosperm development.Thickening the aleurone layer has been proposed to significantly increase t...Aleurone forms the outermost layer of the rice endosperm and plays a critical role in apoplastic nutrient uptake during endosperm development.Thickening the aleurone layer has been proposed to significantly increase the nutrient content of rice grains.In this study,we used a CRISPR/Cas9-mediated precise base editing method to target OsROS1,a gene associated with aleurone thickness,in the background of the japonica glutinous rice cultivar Zhennuo 19。展开更多
Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of gen...Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of genetic diversity in the existing germplasm resources. In the present study, a collection of 380 sweetpotato accessions assembled from different agro-climatic zones of China and other countries were genotyped using 30 SSR primer pairs. Model-based structure analysis separated the germplasm into three populations, P1, P2 and P3, containing 228, 133 and 19 accessions, respectively, which was consistent with the results of phylogenic and principal component analysis(PCA). Analysis of molecular variance(AMOVA) revealed significant genetic differentiation among inferred populations, accounting for 16.47% of the total molecular variance, however, the differences between the regions were not significant, the total variation were due to the differences between the genotypes within the population. Pairwise fixation index(F ST) suggested that populations P1 and P3 had the highest differentiation, while populations P1 and P2 had the lowest differentiation. The diversity among populations was wide, which confirmed the genetic distinction of populations. Through comparing model-based structure and domestication-based classification, it was found that the accessions of population P1 mainly belonged to modern cultivars, and the accessions of populations P2 and P3 basically corresponded to landraces, by which we suggest that modern cultivars maybe had experienced a two-step domestication history. Our results illustrated clear genetic relationships among 380 sweetpotato accessions, exhibiting the potential of accelerating the process of future sweetpotato breeding program by molecular marker based parental selection.展开更多
Better understanding of genotype-by-environment interaction(GEI)is expected to provide a solid foundation for genetic improvement of crop productivity especially under drought-prone environments.To elucidate the genet...Better understanding of genotype-by-environment interaction(GEI)is expected to provide a solid foundation for genetic improvement of crop productivity especially under drought-prone environments.To elucidate the genetic basis of the plant and ear height,2 F2:3 populations were derived from the crosses of Qi 319 × Huangzaosi(Q/H)and Ye 478 × Huangzaosi(Y/H)with 230 and 235 families,respectively,and their parents were evaluated under 3 diverse environments in Henan,Beijing,and Xinjiang,China during the year of 2007 and 2008,and all the lines were also evaluated under water stress environment.The mapping results showed that a total of 21 and 12 QTLs were identified for plant height in the Q/H and Y/H population,respectively,and 24 and 13 QTLs for ear height,respectively.About 56 and 73% of the QTLs for 2 traits did not present significant QTL-by-environment interaction(QEI)in the normal joint analyses for Q/H and Y/H population,respectively,and about 73% of the QTLs detected did not show significant QEI according to joint analyses for stress condition in Q/H.Most of the detected major QTLs exhibited high stability across different environments.Besides,several major QTLs were detected with large and consistent effect under normal condition(Chr.6 and 7 in Q/H;Chr.1,3 and 9 in Y/H),or across 2 water regimes(Chr.1,8 and 10 for in Q/H).There were several constitutive QTLs(3 for Q/H and 1 for Y/H)with no or minor QTL-by-environment for the 2 populations.Finally,we found several genomic regions(Chr.1,10,etc.)to be co-located across the populations,which could provide useful reference for genetic improvement of these traits in maize breeding programs.Comparative genomic analysis revealed that 3 genes/genetic segments associated with plant height in rice were orthologous to these 3 identified genomic regions carrying the major QTLs for plant and ear height on Chr.1,6,and 8,respectively.展开更多
To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure ...To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure of two Waxy(Wx) alleles japonica rice cultivars Nanjing 9108(NJ9108) and Huaidao 5(HD5) under four N rates(0, 150, 300, and 450 kg ha^-1). Sensory and pasting properties of the two cultivars varied depending on N rates. Compared with the control(0 kg ha^-1), the overall eating quality and sensory value were significantly decreased under the N rates of 300 and 450 kg ha^-1. Further, conventional descriptive analysis showed that the stickiness and retrogradation of cooked rice were significantly decreased. These results indicated that application of N fertilizer seems to affect the texture of cooked rice, causing it to be less sticky, lowering its retrogradation, and consequently reducing its palatability. Results from rapid visco analyzer(RVA) revealed that the peak and breakdown viscosities significantly decreased, while the setback viscosity and peak time increased under the N rates of 300 and 450 kg ha^-1. However, no significant difference was observed when the N rate was 150 kg ha^-1, indicating that less N fertilization can maintain rice ECQ. As the N rate increasing, protein content increased, whereas apparent amylose content, starch content, and gel consistency almost unchanged. Interestingly, compared with the control, under N treatments, the percentage of short amylopectin branches in NJ9108 was decreased, but increased in HD5, as controlled by amylopectin synthesis-related genes. Notably, SSI and BEIIb were down-regulated in NJ9108, whereas BEIIb was up-regulated in HD5. Thus, the palatability of both rice cultivars was significantly decreased under excessive N fertilization as a consequence of reduced stickiness and retrogradation of the cooked rice, which might have resulted from an elevated protein content and altered amylopectin fine structure. In addition, amylopectin synthesis appeared to be affected by N fertilizer and the genotype of the rice cultivar.展开更多
Rice with low glutelin content is suitable as functional food for patients affected by kidney failure. Low glutelincontent gene Lgc1 in rice has a 3.5-kb deletion between two highly similar glutelin genes GluB4 and Gl...Rice with low glutelin content is suitable as functional food for patients affected by kidney failure. Low glutelincontent gene Lgc1 in rice has a 3.5-kb deletion between two highly similar glutelin genes GluB4 and GluB5, which locates on the short arm of chromosome 2. To improve the selection efficiency in low glutelin-content rice breeding, two molecular markers designated as InDel-Lgc1-1 and InDel-Lgc1-2 were developed to detect the low glutelin-content gene Lgc1. A double PCR detection indicated that combined use of the two markers could easily distinguish the genotypes of Lgc1 from different rice varieties. Therefore, as a simple and low-cost technique, the molecular marker could be widely used to identify different varieties with Lgc1 gene and applied in marker-assisted selection of low glutelin-content rice.展开更多
In this study we report the results of a decade-long breeding program for japonica super rice made by Nanjing Branch of Chinese National Center for Rice Improvement in Jiangsu Academy of Agricultural Sciences. We conc...In this study we report the results of a decade-long breeding program for japonica super rice made by Nanjing Branch of Chinese National Center for Rice Improvement in Jiangsu Academy of Agricultural Sciences. We concluded that selection of parents with good comprehensive traits and complementary advantages and disadvantages of both parents in the hybrid combination, and early selection of high heritability traits in earlier segregating generations could significantly improve the breeding efficiency. The use of closely-linked functional markers in pyramiding of multiple genes could greatly increase breeding efficiency, avoiding time-consuming and laborious steps that were used in traditional breeding program. It is also important to coordinate the yield components with variety characteristics such as yield stability, wide adaptability, lodging resistance, and an attractive grain appearance during late growth stage of rice.展开更多
The objective of this study was to characterize yellow(stripe) rust resistance gene(s) in 52 commercial wheat cultivars from Yunnan Province in China,and to provide information for their rational deployment in field.S...The objective of this study was to characterize yellow(stripe) rust resistance gene(s) in 52 commercial wheat cultivars from Yunnan Province in China,and to provide information for their rational deployment in field.Seedlings of wheat cultivars were inoculated with 25 differential isolates of Puccinia striiformis from foreign and home to postulate resistance genes to yellow rust,and then validated by pedigree.There were 10 probable resistance genes characterized in these cultivars,in which,Yr9 was most commonly postulated to be present in thirteen cultivars.Yr21,the second,was present in four cultivars.Yr8,the third,were present in three cultivars.Yr6,Yr17 and Yr26,the fourth,was present in two cultivars respectively.The other gene(s) such as,Yr2+YrA,Yr7 and Yr27,were only present in single cultivar(s);unknown gene(s) or gene(s) combination(s) were present in 22 cultivars.One cultivar(Yunmai 42) had no resistance gene tested in this study.Cultivars such as Yunmai 52,Mian 1971-98,Kunmai 4,and Yunmai 56 carried effective genes and can be popularized mainly;Yr9 should be planted with other Yr genes.In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust.Yunmai 42 should be reduced to avoid rust breakout.Unknown gene cultivars should be utilized and be researched deeply.展开更多
The waxy gene(Wx) in rice, which encodes the granule bound starch synthase enzyme, is responsible for amylose synthesis. Glutinous(sticky) rice has little or no amylose that can be used in various applications, such a...The waxy gene(Wx) in rice, which encodes the granule bound starch synthase enzyme, is responsible for amylose synthesis. Glutinous(sticky) rice has little or no amylose that can be used in various applications, such as brewing. In this study, knockout of the Wx gene with CRISPR/Cas9 technology was conducted in two elite japonica rice lines, Huaidao 5(HD5) and Suken 118(SK118), aiming to develop elite sticky rice varieties. We achieved six homozygous T_0 plants with more than 200 bp deletion in the Wx gene, as well as 36 wx-HD5 and 18 wx-SK118 homozygous transgene-free plants in the T_1 generation. The seeds of all the mutants were white and opaque, similar to those of sticky rice, and contained only 2.6%–3.2% amylose. Results of scanning electron microscopy showed that the quality of rice did not change. In conclusion, we successfully developed two elite sticky rice varieties.展开更多
Dissolved oxygen and nitrogen form have important effects on rice root growth and nitrogen availability.An indica hybrid rice,Guodao 1,and a conventional japonica rice,Xiushui 09,were cultured in hypoxic nutrient solu...Dissolved oxygen and nitrogen form have important effects on rice root growth and nitrogen availability.An indica hybrid rice,Guodao 1,and a conventional japonica rice,Xiushui 09,were cultured in hypoxic nutrient solution with NH4NO3 or(NH4)2SO4 as the nitrogen source for six weeks in pools.A portion of the Guodao 1 seedlings after treatment in the pools for four weeks were transferred to a split-root system at different dissolved oxygen contents and cultured for an additional two weeks.Biomass,root morphological traits and nitrogen accumulation were recorded.Under the low rhizosphere dissolved oxygen content(0-1.0 mg/L),plant biomass was significantly increased under NH4NO3-N supply by about 69% in Guodao 1 and 41% in Xiushui 09 compared with those under NH4+-N alone.Similar results were observed for root number,maximum root length,root dry weight and root activity.Nitrogen accumulations in roots and shoots were increased by 60% and 52% for Guodao 1,and by 41% and 33% for Xiushui 09,respectively,in the NH4NO3-N treatment.In the split-root system,the high rhizosphere dissolved oxygen content(8.0-9.0 mg/L) promoted root growth and development.Root biomass was increased by 21.6%,root number by 27%,maximum root length by 14%,and root volume by 10%.Moreover,nitrogen accumulation in roots was increased by 11% under high rhizosphere oxygen conditions.In conclusion,enhanced dissolved oxygen content and combined ammonium-nitrate nitrogen source have positive effects on root growth and nitrogen accumulation of rice plants.展开更多
Japonica rice variety Kanto 194 as the donor of resistance gene Stv-b^i and low-amylose content gene Wx-mq was used to improve the resistance and eating quality of Wuyujing 3 by the breeding strategy of backcross. In ...Japonica rice variety Kanto 194 as the donor of resistance gene Stv-b^i and low-amylose content gene Wx-mq was used to improve the resistance and eating quality of Wuyujing 3 by the breeding strategy of backcross. In continuous backcross and selfcross generations, the related molecular markers with Stv-b^i and Wx-mq genes were utilized for genotypic detection by associated with resistance identification of rice stripe disease and agronomic traits selection. Finally, 10 improved lines with homozygous genotype Stv-b^iStv-b^iWx-mq Wx-mq were obtained from BC_3F_4 generation. The results of comparative analysis indicated that most characters of these lines were consistent with those of recipient parent Wuyujing 3, except for the improved resistance, appearance and eating quality. By evaluation of the comprehensive performance of them, two excellent lines K01 and K04 were selected for further experiments.展开更多
Layered leaf area index (LAIk) is one of the major determinants for rice canopy. The objective of this study is to attain rice LAI k using morphological traits especially leaf traits that affected plant type. A theore...Layered leaf area index (LAIk) is one of the major determinants for rice canopy. The objective of this study is to attain rice LAI k using morphological traits especially leaf traits that affected plant type. A theoretical model based on rice geometrical structure was established to describe LAI k of rice with leaf length (Li), width (Wi), angle (Ai), and space (Si), and plant pole height (H) at booting and heading stages. In correlation with traditional manual measurement, the model was performed by high R2-values (0.95-0.89, n=24) for four rice hybrids (Liangyoupeijiu, Liangyou E32, Liangyou Y06, and Shanyou 63) with various plant types and four densities (3 750, 2 812, 1 875, and 1 125 plants per 100 m2) of a particular hybrid (Liangyoupeijiu). The analysis of leaf length, width, angle, and space on LAI k for two hybrids (Liangyoupeijiu and Shanyou 63) showed that leaves length and space exhibited greater effects on the change of rice LAI k . The radiation intensity showed a significantly negative exponential relation to the accumulation of LAI k , which agreed to the coefficient of light extinction (K). Our results suggest that plant type regulates radiation distribution through changing LAI k . The present model would be helpful to acquire leaf distribution and judge canopy structure of rice field by computer system after a simple and less-invasive measurement of leaf length, width, angle (by photo), and space at field with non-dilapidation of plants.展开更多
In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selecte...In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selected as explants to study the callus induction,differentiation and regeneration rates on different media.The higher callus induction (61.7-89.2%) was observed in japonica rice,when cytokinin was added at lower concentration (0.3 mg L-1 6-BA) in M8 basal medium,supplemented with 30 g L-1 sucrose,8 g L-1 agar and 2 mg L-1 2,4-D.Further,the addition of two cytokinins (2 mg L-1 6-BA,0.5 mg L-1 KT) and 1 mg L-1 NAA in the M8 basal supplemented medium resulted in 9.1-100% of the callus induction in indica rice.The percent callus induction in hybrid rice varieties was 40-86.3% when addition of 1 mg L-1 6-BA and 1 mg L-1 KT was added,and the cytokinins was required by the japonica and indica rice varieties in the M8 basal supplemented medium.It was observed that when the 0.5 mg L-1 2,4-D and 1 mg L-1 6-BA were added in japonica rice,and 0.2 mg L-1 2,4-D and 0.5 mg L-1 6-BA were added in indica and hybrid rice in the MS different media,the regeneration rates were 9.2-59.5%,3.6-87.5% and 17.2-43.2% for japonica,indica and hybrid rice,respectively.Thus,the regeneration technology with higher output is established in the mature embryos of similar rice varieties.展开更多
Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New...Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars(53 in 2007 and 48 in 2008) were grown in Taoyuan,Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107(a large-panicle type) and Xieyou 107(a heavy-panicle type), were planted in Taoyuan, Yunnan province and Nanjing,Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes.Growth duration(GD), leaf area index(LAI), panicles per m2(PN), and spikelets per m2(SM) were significantly and positively correlated with grain yield(GY) over all years. Sequential path analysis identified PN and panicle weight(PW) as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height(PH), days from heading to maturity(HM), and grain weight(GW) were stable traits that showed little variation across sites or years, whereas GD(mainly the pre-heading period, PHP) and PN varied significantly across locations. To achieve a yield of 15 t ha-1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m-2, and a GW of 29–31 mg.展开更多
Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities...Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities,is distributed in all edible parts of sweetpotato.However,little is known about the specific metabolism of CGA in sweetpotato.In this study,IbPAL1,which encodes an endoplasmic reticulum-localized phenylalanine ammonia lyase(PAL),was isolated and characterized in sweetpotato.CGA accumulation was positively associated with the expression pattern of IbPAL1 in a tissue-specific manner,as further demonstrated by overexpression of IbPAL1.Overexpression of IbPAL1 promoted CGA accumulation and biosynthetic pathway genes expression in leaves,stimulated secondary xylem cell expansion in stems,and inhibited storage root formation.Our results support a potential role for IbPAL1 in sweetpotato CGA biosynthesis and establish a theoretical foundation for detailed mechanism research and nutrient improvement in sweetpotato breeding programs.展开更多
The rice starch viscosity characteristics, which can be indicated by Rapid Visco Analyzer profile (RVA profile), have been proved useful for the evaluation of cooking and eating quality in rice breeding program. To st...The rice starch viscosity characteristics, which can be indicated by Rapid Visco Analyzer profile (RVA profile), have been proved useful for the evaluation of cooking and eating quality in rice breeding program. To study the inheritance of the RVA profile, an F2 population of Wuyujing 3/Aichi 106 was used. The results indicated that the peak viscosity (PKV) was a typical quantitative character, and the hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV), breakdown viscosity (BDV), and consistence viscosity (CSV) might be controlled by one major gene and several minor genes. To elucidate the genetic basis of the paste viscosity characteristics, a recombinant inbred line (RIL) population derived from Nikken 2/Milyang 23 and its genetic linkage map were used to map the QTLs controlling RVA profiles in 2005 and 2006. A total of 34 QTLs distributed on chromosomes 1, 2, 3, 4, 6, 7 and 8 were detected, including 19 and 15 QTLs in 2005 and 2006, respectively. Eight QTLs were both detected in the two years, qHPV6, qCPV6, qCSV6, qSBV6, and qBDV6 were located on chromosome 6, while qHPV2, qCSV2, and qCPV2 were on chromosome 2.展开更多
By replacing leaf area index (LAI) with effective leaf area index (ELAI) through introduction of leaf rolling index (LRI), the distributions of photosynthetically active radiation (PAR) in the canopies of three hybrid...By replacing leaf area index (LAI) with effective leaf area index (ELAI) through introduction of leaf rolling index (LRI), the distributions of photosynthetically active radiation (PAR) in the canopies of three hybrid rice combinations, Liangyou E32 with high LRI, Liangyoupeijiu with moderate LRI and Shanyou 63 with non-rolling leaves (normal), were simulated. The model based on ELAI could predict more accurately than that based on LAI. The PAR interception, conversion and utilization efficiency in the three combinations were studied to evaluate their optimal LRI and LAI. The PAR utilization efficiency of Liangyou E32 was lower due to excessive rolling leaves and less ELAI, and that of Shanyou 63 was also lower because of the faulty PAR interception and lower photosynthetic rate and saturation point at lower layer in canopy. Compared with the above two combinations, Liangyoupeijiu showed more appropriate distribution of PAR interception and conversion efficiency in canopy, and higher PAR utilization efficiency. The optimal LRI and LAI for Liangyoupeijiu were 0.11 and 7.6, respectively, which were close to the observed value, 0.11 and 7.9, respectively. However, the optimum LAI was 9.8 for Liangyou E32 and 6.2 for Shanyou 63, larger or smaller than those under the current plant density, which led to lower efficiency of PAR utilization. Besides, the optimum LRI for Liangyou E32 and Shanyou 63 were 0.12 and 0.08, respectively, which were close to the actual LRI for Liangyoupeijiu (0.11).展开更多
基金supported by the National Key Research and Development Program of China (2019YFD1001300,2019YFD1001305)the China Agriculture Research System of MOF and MARA-Food Legumes (CARS-08)the Agricultural Science and Technology Innovation Program of CAAS。
文摘Drought stress severely impairs common bean production.For facilitating drought-resistance breeding in common bean,molecular markers were identified in a genome-wide level marker–trait association study.A panel of 210 common bean accessions showed large variation in 11 agronomic traits at the adult stage(plant height,pod number per plant,seed number per pod,seed number per plant,seed yield per plant,pod length,harvest index,pod harvest index,days to maturity,hundred-seed weight,and seed yield)under two water conditions.The coefficient of variation ranged from 6.21% for pod harvest index to51.00% for seed number per plant under well-watered conditions,and from 4.05% for days to maturity to 40.72% for seed number per plant under drought stress.In a genome-wide association study,119quantitative-trait loci were associated with drought resistance,including 41 adjacent to known loci.Among these loci,12 were found to be associated with at least two traits.Three major loci were identified at Pv01 and Pv02.A set of candidate genes were found that encode MYBs,AREBs,WKRYs,and protein kinases.These results reveal promising alleles that control drought resistance,shedding light on the genetic basis of drought resistance and accelerating future efforts for drought resistance improvement in common bean.
基金supported by the National Key Research and Development Program of China(2019YFD1001300,2019YFD1001301)the Earmarked Fund for CARS-10-Sweetpotato(CARS-10)+1 种基金the Beijing Food Crops Innovation Consortium Program(BAIC02-2022)Hebei Key R&D Program(20326320D,22322911D)。
文摘Sweetpotato(Ipomoea batatas(L.)Lam.)is a widely grown food crop especially in developing countries.Increasing storage-root yield and dry-matter content has been the main breeding objective of the crop,and DNA marker-assisted breeding is needed for this purpose.In this study,using a mapping population of 500 F1 individuals from a cross between Xushu 18(female)and Xu 781(male),we constructed a highdensity genetic linkage map of sweetpotato using 601 simple-sequence repeat(SSR)primer pairs.The Xushu 18 map contained 90 linkage groups with 5547 SSR markers and spanned 18,263.5 cM,and the Xu 781 map contained 90 linkage groups with 4599 SSR markers and spanned 18,043.7 cM,representing the highest genome coverage yet reported for sweetpotato.We identified 33 QTL for storage-root yield and 16 QTL for dry-matter content,explaining respectively 6.5%–47.5%and 3.2%–18.9%of variation.These results provide a foundation for fine-mapping and cloning of QTL and for marker-assisted breeding in sweetpotato.
基金funded by the National Natural Science Foundation of China (Grant No. 31901525)the Natural Science Foundation of Jiangsu Province+2 种基金China (Grant No. BK20190255)the International Cooperation and Exchange of the National Natural Science Foundation of China (Grant No. 31861143011)the Revitalization of Jiangsu Seed Industry in China (Grant No. JBGS[2021]039)。
文摘Grain size, determined by grain length, grain width and grain thickness, is associated with grain yield and quality. Many genes controlling grain size were cloned and their related regulatory mechanisms were clearly clarified. However, whether these genes can be directly introduced into japonica rice for grain size improvement is unknown.
基金supported by the National Natural Science Foundation of China(Grant No.31901485)Jiangsu Science and Technology Development Program,China(Grant No.BE2021301)China Agriculture Research System(Grant No.CARS-01-67).
文摘Grain size is controlled by many QTLs and/or genes.Despite intensive study,the genetic interactions between these QTLs/genes remain largely unclear.We previously found that the japonica large-grain rice cultivar TD70 with 1000-grain weight of 68.6 g carries superior alleles at the loci GW2,GS3,qGL3,GS5 and GW8,all of which are known to control grain size,while the indica rice variety Kasalath with 1000-grain weight of 19.1 g has normal alleles at these loci.
基金supported by the Ministry of Agriculture and Rural Affairs of China,the Jiangsu Provincial Key Research and Development Program(Grant No.BE2022383)Key Laboratory of Jiangsu Province for Agrobiology,China(Grant No.JKLA2021-ZD01)the Exploratory Project of the Jiangsu Academy of Agricultural Sciences,China(Grant No.ZX(21)1201).
文摘Aleurone forms the outermost layer of the rice endosperm and plays a critical role in apoplastic nutrient uptake during endosperm development.Thickening the aleurone layer has been proposed to significantly increase the nutrient content of rice grains.In this study,we used a CRISPR/Cas9-mediated precise base editing method to target OsROS1,a gene associated with aleurone thickness,in the background of the japonica glutinous rice cultivar Zhennuo 19。
基金supported by the Hubei Engineering and Technology Research Centre of Sweetpotato,Chinathe International Cooperation Program,Ministry of Science and Technology of China (2011DFB31620)+3 种基金the Introduction and Utiliztion of Sweetpotato Resources in USA (2013-Z61)the Characteristic Discipline of Hubei Academy of Agricultural Sciences,Chinathe Science and Technology Innovation Centre of Hubei Academy of Agricultural Sciences,China (2007-620-001-03)the China Agriculture Research System (CARS-11-C-15)
文摘Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of genetic diversity in the existing germplasm resources. In the present study, a collection of 380 sweetpotato accessions assembled from different agro-climatic zones of China and other countries were genotyped using 30 SSR primer pairs. Model-based structure analysis separated the germplasm into three populations, P1, P2 and P3, containing 228, 133 and 19 accessions, respectively, which was consistent with the results of phylogenic and principal component analysis(PCA). Analysis of molecular variance(AMOVA) revealed significant genetic differentiation among inferred populations, accounting for 16.47% of the total molecular variance, however, the differences between the regions were not significant, the total variation were due to the differences between the genotypes within the population. Pairwise fixation index(F ST) suggested that populations P1 and P3 had the highest differentiation, while populations P1 and P2 had the lowest differentiation. The diversity among populations was wide, which confirmed the genetic distinction of populations. Through comparing model-based structure and domestication-based classification, it was found that the accessions of population P1 mainly belonged to modern cultivars, and the accessions of populations P2 and P3 basically corresponded to landraces, by which we suggest that modern cultivars maybe had experienced a two-step domestication history. Our results illustrated clear genetic relationships among 380 sweetpotato accessions, exhibiting the potential of accelerating the process of future sweetpotato breeding program by molecular marker based parental selection.
基金supported by grants provided by the Ministry of Science and Technology of China(2006CB101700,2009CB118401,2006BAD13B03)National Natural Science Foundation of China(30730063)
文摘Better understanding of genotype-by-environment interaction(GEI)is expected to provide a solid foundation for genetic improvement of crop productivity especially under drought-prone environments.To elucidate the genetic basis of the plant and ear height,2 F2:3 populations were derived from the crosses of Qi 319 × Huangzaosi(Q/H)and Ye 478 × Huangzaosi(Y/H)with 230 and 235 families,respectively,and their parents were evaluated under 3 diverse environments in Henan,Beijing,and Xinjiang,China during the year of 2007 and 2008,and all the lines were also evaluated under water stress environment.The mapping results showed that a total of 21 and 12 QTLs were identified for plant height in the Q/H and Y/H population,respectively,and 24 and 13 QTLs for ear height,respectively.About 56 and 73% of the QTLs for 2 traits did not present significant QTL-by-environment interaction(QEI)in the normal joint analyses for Q/H and Y/H population,respectively,and about 73% of the QTLs detected did not show significant QEI according to joint analyses for stress condition in Q/H.Most of the detected major QTLs exhibited high stability across different environments.Besides,several major QTLs were detected with large and consistent effect under normal condition(Chr.6 and 7 in Q/H;Chr.1,3 and 9 in Y/H),or across 2 water regimes(Chr.1,8 and 10 for in Q/H).There were several constitutive QTLs(3 for Q/H and 1 for Y/H)with no or minor QTL-by-environment for the 2 populations.Finally,we found several genomic regions(Chr.1,10,etc.)to be co-located across the populations,which could provide useful reference for genetic improvement of these traits in maize breeding programs.Comparative genomic analysis revealed that 3 genes/genetic segments associated with plant height in rice were orthologous to these 3 identified genomic regions carrying the major QTLs for plant and ear height on Chr.1,6,and 8,respectively.
基金funded by the China Postdoctoral Science Foundation(2017M611753)the earmarked fund for Agriculture Research System of China(CARS-01-62)+3 种基金the National Key R&D Program of China(2015BAD01B02)the Natural Science Foundation of Jiangsu Province,China(BK20180302)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX[17]3009)the Project of Henan Key Laboratory of Tea Plant Comprehensive Utilization in South Henan,China(HNKLTCU2018004)。
文摘To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure of two Waxy(Wx) alleles japonica rice cultivars Nanjing 9108(NJ9108) and Huaidao 5(HD5) under four N rates(0, 150, 300, and 450 kg ha^-1). Sensory and pasting properties of the two cultivars varied depending on N rates. Compared with the control(0 kg ha^-1), the overall eating quality and sensory value were significantly decreased under the N rates of 300 and 450 kg ha^-1. Further, conventional descriptive analysis showed that the stickiness and retrogradation of cooked rice were significantly decreased. These results indicated that application of N fertilizer seems to affect the texture of cooked rice, causing it to be less sticky, lowering its retrogradation, and consequently reducing its palatability. Results from rapid visco analyzer(RVA) revealed that the peak and breakdown viscosities significantly decreased, while the setback viscosity and peak time increased under the N rates of 300 and 450 kg ha^-1. However, no significant difference was observed when the N rate was 150 kg ha^-1, indicating that less N fertilization can maintain rice ECQ. As the N rate increasing, protein content increased, whereas apparent amylose content, starch content, and gel consistency almost unchanged. Interestingly, compared with the control, under N treatments, the percentage of short amylopectin branches in NJ9108 was decreased, but increased in HD5, as controlled by amylopectin synthesis-related genes. Notably, SSI and BEIIb were down-regulated in NJ9108, whereas BEIIb was up-regulated in HD5. Thus, the palatability of both rice cultivars was significantly decreased under excessive N fertilization as a consequence of reduced stickiness and retrogradation of the cooked rice, which might have resulted from an elevated protein content and altered amylopectin fine structure. In addition, amylopectin synthesis appeared to be affected by N fertilizer and the genotype of the rice cultivar.
基金supported by the National Transgenic Crops Program, China (Grant No. 2008ZX08001-006)the Research Funds for Public Benefit in Ministry of Agriculture, China (Grant No. 200803056)+1 种基金the Key Support Program of Jiangsu Science and Technology, China (Grant No. BE2008354)the Self-directed Innovation Fund of Agricultural Science and Technology in Jiangsu Province, China (Grant No. CX [08]603)
文摘Rice with low glutelin content is suitable as functional food for patients affected by kidney failure. Low glutelincontent gene Lgc1 in rice has a 3.5-kb deletion between two highly similar glutelin genes GluB4 and GluB5, which locates on the short arm of chromosome 2. To improve the selection efficiency in low glutelin-content rice breeding, two molecular markers designated as InDel-Lgc1-1 and InDel-Lgc1-2 were developed to detect the low glutelin-content gene Lgc1. A double PCR detection indicated that combined use of the two markers could easily distinguish the genotypes of Lgc1 from different rice varieties. Therefore, as a simple and low-cost technique, the molecular marker could be widely used to identify different varieties with Lgc1 gene and applied in marker-assisted selection of low glutelin-content rice.
基金supported by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2015BAD01B02)the Special Program for Rice Scientific Research,Ministry of Agriculture,China(201603002-5-1)the Construction of Modern Agricultural and Industrial Technology System Project special fund,China(CARS01-47)
文摘In this study we report the results of a decade-long breeding program for japonica super rice made by Nanjing Branch of Chinese National Center for Rice Improvement in Jiangsu Academy of Agricultural Sciences. We concluded that selection of parents with good comprehensive traits and complementary advantages and disadvantages of both parents in the hybrid combination, and early selection of high heritability traits in earlier segregating generations could significantly improve the breeding efficiency. The use of closely-linked functional markers in pyramiding of multiple genes could greatly increase breeding efficiency, avoiding time-consuming and laborious steps that were used in traditional breeding program. It is also important to coordinate the yield components with variety characteristics such as yield stability, wide adaptability, lodging resistance, and an attractive grain appearance during late growth stage of rice.
基金support by the Ministry of Science and Technology,China (2011CB100403)the Ministry of Agriculture,China (200903035)the Special Project from State Key Laboratory for Biology of Plant Diseases and Insect Pests,Chinese Academy of Agricltural Sciences (SKL2009OP09)
文摘The objective of this study was to characterize yellow(stripe) rust resistance gene(s) in 52 commercial wheat cultivars from Yunnan Province in China,and to provide information for their rational deployment in field.Seedlings of wheat cultivars were inoculated with 25 differential isolates of Puccinia striiformis from foreign and home to postulate resistance genes to yellow rust,and then validated by pedigree.There were 10 probable resistance genes characterized in these cultivars,in which,Yr9 was most commonly postulated to be present in thirteen cultivars.Yr21,the second,was present in four cultivars.Yr8,the third,were present in three cultivars.Yr6,Yr17 and Yr26,the fourth,was present in two cultivars respectively.The other gene(s) such as,Yr2+YrA,Yr7 and Yr27,were only present in single cultivar(s);unknown gene(s) or gene(s) combination(s) were present in 22 cultivars.One cultivar(Yunmai 42) had no resistance gene tested in this study.Cultivars such as Yunmai 52,Mian 1971-98,Kunmai 4,and Yunmai 56 carried effective genes and can be popularized mainly;Yr9 should be planted with other Yr genes.In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust.Yunmai 42 should be reduced to avoid rust breakout.Unknown gene cultivars should be utilized and be researched deeply.
基金supported by the National Key Research and Development Program (Grant No. 2017YFD0100403)the Jiangsu Province Key Research and Development Program (Modern Agriculture) Project (Grant No. BE2017345-2)+1 种基金the Exploratory Project of the Jiangsu Academy of Agricultural Sciences [Grant No. ZX(17)2014]the Jiangsu Province Natural Science Foundation (Grant No. BK20171326)
文摘The waxy gene(Wx) in rice, which encodes the granule bound starch synthase enzyme, is responsible for amylose synthesis. Glutinous(sticky) rice has little or no amylose that can be used in various applications, such as brewing. In this study, knockout of the Wx gene with CRISPR/Cas9 technology was conducted in two elite japonica rice lines, Huaidao 5(HD5) and Suken 118(SK118), aiming to develop elite sticky rice varieties. We achieved six homozygous T_0 plants with more than 200 bp deletion in the Wx gene, as well as 36 wx-HD5 and 18 wx-SK118 homozygous transgene-free plants in the T_1 generation. The seeds of all the mutants were white and opaque, similar to those of sticky rice, and contained only 2.6%–3.2% amylose. Results of scanning electron microscopy showed that the quality of rice did not change. In conclusion, we successfully developed two elite sticky rice varieties.
基金supported by the National Natural Science Foundation of China(Grant No.30571102)the Key Projects in the National Science & Technology Pillar Program of China(Grant No.2006BAD02A13)the Provincial Natural Science Foundation of Zhejiang(Grant No.Y3100270)
文摘Dissolved oxygen and nitrogen form have important effects on rice root growth and nitrogen availability.An indica hybrid rice,Guodao 1,and a conventional japonica rice,Xiushui 09,were cultured in hypoxic nutrient solution with NH4NO3 or(NH4)2SO4 as the nitrogen source for six weeks in pools.A portion of the Guodao 1 seedlings after treatment in the pools for four weeks were transferred to a split-root system at different dissolved oxygen contents and cultured for an additional two weeks.Biomass,root morphological traits and nitrogen accumulation were recorded.Under the low rhizosphere dissolved oxygen content(0-1.0 mg/L),plant biomass was significantly increased under NH4NO3-N supply by about 69% in Guodao 1 and 41% in Xiushui 09 compared with those under NH4+-N alone.Similar results were observed for root number,maximum root length,root dry weight and root activity.Nitrogen accumulations in roots and shoots were increased by 60% and 52% for Guodao 1,and by 41% and 33% for Xiushui 09,respectively,in the NH4NO3-N treatment.In the split-root system,the high rhizosphere dissolved oxygen content(8.0-9.0 mg/L) promoted root growth and development.Root biomass was increased by 21.6%,root number by 27%,maximum root length by 14%,and root volume by 10%.Moreover,nitrogen accumulation in roots was increased by 11% under high rhizosphere oxygen conditions.In conclusion,enhanced dissolved oxygen content and combined ammonium-nitrate nitrogen source have positive effects on root growth and nitrogen accumulation of rice plants.
基金supported by the Special Fund of Construction of Modern Agricultural and Industrial Technology System Project (Grant No. CARS-01-47)the Special Fund for Agro-scientific Research in the Public Interest (Grant No. 201503002-5-1)the Key Research & Development Program of Jiangsu Province (Grant No. BE2015363-3) in China
文摘Japonica rice variety Kanto 194 as the donor of resistance gene Stv-b^i and low-amylose content gene Wx-mq was used to improve the resistance and eating quality of Wuyujing 3 by the breeding strategy of backcross. In continuous backcross and selfcross generations, the related molecular markers with Stv-b^i and Wx-mq genes were utilized for genotypic detection by associated with resistance identification of rice stripe disease and agronomic traits selection. Finally, 10 improved lines with homozygous genotype Stv-b^iStv-b^iWx-mq Wx-mq were obtained from BC_3F_4 generation. The results of comparative analysis indicated that most characters of these lines were consistent with those of recipient parent Wuyujing 3, except for the improved resistance, appearance and eating quality. By evaluation of the comprehensive performance of them, two excellent lines K01 and K04 were selected for further experiments.
基金supported by the National Natural Science Foundation of China (NSFC,30871479)
文摘Layered leaf area index (LAIk) is one of the major determinants for rice canopy. The objective of this study is to attain rice LAI k using morphological traits especially leaf traits that affected plant type. A theoretical model based on rice geometrical structure was established to describe LAI k of rice with leaf length (Li), width (Wi), angle (Ai), and space (Si), and plant pole height (H) at booting and heading stages. In correlation with traditional manual measurement, the model was performed by high R2-values (0.95-0.89, n=24) for four rice hybrids (Liangyoupeijiu, Liangyou E32, Liangyou Y06, and Shanyou 63) with various plant types and four densities (3 750, 2 812, 1 875, and 1 125 plants per 100 m2) of a particular hybrid (Liangyoupeijiu). The analysis of leaf length, width, angle, and space on LAI k for two hybrids (Liangyoupeijiu and Shanyou 63) showed that leaves length and space exhibited greater effects on the change of rice LAI k . The radiation intensity showed a significantly negative exponential relation to the accumulation of LAI k , which agreed to the coefficient of light extinction (K). Our results suggest that plant type regulates radiation distribution through changing LAI k . The present model would be helpful to acquire leaf distribution and judge canopy structure of rice field by computer system after a simple and less-invasive measurement of leaf length, width, angle (by photo), and space at field with non-dilapidation of plants.
基金supported by the National Natural Science Foundation of China (30871459)the Key Project of Cultivate New Varieties of Genetically Modified Technology of China (2008ZX08001-004)+1 种基金the Agricultural Science and Technology Innovation Fundation of Jiangsu Province, China (CX[07]603)the Fundation of Jiangsu Academy of Agricultural Sciences, China (6510707 and 6110704)
文摘In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selected as explants to study the callus induction,differentiation and regeneration rates on different media.The higher callus induction (61.7-89.2%) was observed in japonica rice,when cytokinin was added at lower concentration (0.3 mg L-1 6-BA) in M8 basal medium,supplemented with 30 g L-1 sucrose,8 g L-1 agar and 2 mg L-1 2,4-D.Further,the addition of two cytokinins (2 mg L-1 6-BA,0.5 mg L-1 KT) and 1 mg L-1 NAA in the M8 basal supplemented medium resulted in 9.1-100% of the callus induction in indica rice.The percent callus induction in hybrid rice varieties was 40-86.3% when addition of 1 mg L-1 6-BA and 1 mg L-1 KT was added,and the cytokinins was required by the japonica and indica rice varieties in the M8 basal supplemented medium.It was observed that when the 0.5 mg L-1 2,4-D and 1 mg L-1 6-BA were added in japonica rice,and 0.2 mg L-1 2,4-D and 0.5 mg L-1 6-BA were added in indica and hybrid rice in the MS different media,the regeneration rates were 9.2-59.5%,3.6-87.5% and 17.2-43.2% for japonica,indica and hybrid rice,respectively.Thus,the regeneration technology with higher output is established in the mature embryos of similar rice varieties.
基金supported by the National Key Technology R&D Program of China (2011BAD16B14, 2012BAD20B05, 2012BAD04B08, and 2013BAD20B05)
文摘Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars(53 in 2007 and 48 in 2008) were grown in Taoyuan,Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107(a large-panicle type) and Xieyou 107(a heavy-panicle type), were planted in Taoyuan, Yunnan province and Nanjing,Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes.Growth duration(GD), leaf area index(LAI), panicles per m2(PN), and spikelets per m2(SM) were significantly and positively correlated with grain yield(GY) over all years. Sequential path analysis identified PN and panicle weight(PW) as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height(PH), days from heading to maturity(HM), and grain weight(GW) were stable traits that showed little variation across sites or years, whereas GD(mainly the pre-heading period, PHP) and PN varied significantly across locations. To achieve a yield of 15 t ha-1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m-2, and a GW of 29–31 mg.
基金supported by the National Key Research and Development Program of China(2019YFD1001302 and 2019YFD1001300)National Natural Science Foundation of China(31701483 and 31601382)+2 种基金Jiangsu Agricultural Science and Technology Independent Innovation Fund[CX(19)3063]the National Technical System of Sweetpotato Industry(CARS-10-C3)Jiangsu Province Science and Technology Support Program(BK20171325)。
文摘Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities,is distributed in all edible parts of sweetpotato.However,little is known about the specific metabolism of CGA in sweetpotato.In this study,IbPAL1,which encodes an endoplasmic reticulum-localized phenylalanine ammonia lyase(PAL),was isolated and characterized in sweetpotato.CGA accumulation was positively associated with the expression pattern of IbPAL1 in a tissue-specific manner,as further demonstrated by overexpression of IbPAL1.Overexpression of IbPAL1 promoted CGA accumulation and biosynthetic pathway genes expression in leaves,stimulated secondary xylem cell expansion in stems,and inhibited storage root formation.Our results support a potential role for IbPAL1 in sweetpotato CGA biosynthesis and establish a theoretical foundation for detailed mechanism research and nutrient improvement in sweetpotato breeding programs.
基金supported by the National High- tech Research and Development Program of China (Grant No. 2006AA100101)the Super-rice Breeding and Demonstration Program of Chinese Ministry of Agriculture+1 种基金the Special Research Program on Key Technology of Agricultural Structure Adjustment (Grant No. 05-01-05B),ChinaJiangsu High Technology Program , China (Grant No. BG2004304)
文摘The rice starch viscosity characteristics, which can be indicated by Rapid Visco Analyzer profile (RVA profile), have been proved useful for the evaluation of cooking and eating quality in rice breeding program. To study the inheritance of the RVA profile, an F2 population of Wuyujing 3/Aichi 106 was used. The results indicated that the peak viscosity (PKV) was a typical quantitative character, and the hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV), breakdown viscosity (BDV), and consistence viscosity (CSV) might be controlled by one major gene and several minor genes. To elucidate the genetic basis of the paste viscosity characteristics, a recombinant inbred line (RIL) population derived from Nikken 2/Milyang 23 and its genetic linkage map were used to map the QTLs controlling RVA profiles in 2005 and 2006. A total of 34 QTLs distributed on chromosomes 1, 2, 3, 4, 6, 7 and 8 were detected, including 19 and 15 QTLs in 2005 and 2006, respectively. Eight QTLs were both detected in the two years, qHPV6, qCPV6, qCSV6, qSBV6, and qBDV6 were located on chromosome 6, while qHPV2, qCSV2, and qCPV2 were on chromosome 2.
基金supported by the National High-tech Research and Development Program of China (Grant No.2003AA212040 and No.2006AA100101)
文摘By replacing leaf area index (LAI) with effective leaf area index (ELAI) through introduction of leaf rolling index (LRI), the distributions of photosynthetically active radiation (PAR) in the canopies of three hybrid rice combinations, Liangyou E32 with high LRI, Liangyoupeijiu with moderate LRI and Shanyou 63 with non-rolling leaves (normal), were simulated. The model based on ELAI could predict more accurately than that based on LAI. The PAR interception, conversion and utilization efficiency in the three combinations were studied to evaluate their optimal LRI and LAI. The PAR utilization efficiency of Liangyou E32 was lower due to excessive rolling leaves and less ELAI, and that of Shanyou 63 was also lower because of the faulty PAR interception and lower photosynthetic rate and saturation point at lower layer in canopy. Compared with the above two combinations, Liangyoupeijiu showed more appropriate distribution of PAR interception and conversion efficiency in canopy, and higher PAR utilization efficiency. The optimal LRI and LAI for Liangyoupeijiu were 0.11 and 7.6, respectively, which were close to the observed value, 0.11 and 7.9, respectively. However, the optimum LAI was 9.8 for Liangyou E32 and 6.2 for Shanyou 63, larger or smaller than those under the current plant density, which led to lower efficiency of PAR utilization. Besides, the optimum LRI for Liangyou E32 and Shanyou 63 were 0.12 and 0.08, respectively, which were close to the actual LRI for Liangyoupeijiu (0.11).
