Avirulence effectors(Avrs),encoded by plant pathogens,can be recognized by plants harboring the corresponding resistance proteins,thereby initiating effector-triggered immunity(ETI).In susceptible plants,however,Avrs ...Avirulence effectors(Avrs),encoded by plant pathogens,can be recognized by plants harboring the corresponding resistance proteins,thereby initiating effector-triggered immunity(ETI).In susceptible plants,however,Avrs can function as effectors,facilitating infection via effector-triggered susceptibility(ETS).Mechanisms of Avr-mediated ETS remain largely unexplored.Here we report that the Magnaporthe oryzae effector Avr-PikD enters rice cells via the canonical cytoplasmic secretion pathway and suppresses rice basal defense.Avr-PikD interacts with an LSD1-like transcriptional activator AKIP30 of rice,and AKIP30 is also a positive regulator of rice immunity,whereas Avr-PikD impedes its nuclear localization and suppresses its transcriptional activity.In summary,M.oryzae delivers Avr-PikD into rice cells to facilitate ETS by inhibiting AKIP30-mediated transcriptional regulation of immune response against M.oryzae.展开更多
Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)usin...Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.展开更多
Many studies have already shown that dwarfism and moderate delayed leaf senescence positively impact rice yield,but the underlying molecular mechanism of dwarfism and leaf senescence remains largely unknown.Here,using...Many studies have already shown that dwarfism and moderate delayed leaf senescence positively impact rice yield,but the underlying molecular mechanism of dwarfism and leaf senescence remains largely unknown.Here,using map-based cloning,we identified an allele of DEP2,DDG1,which controls plant height and leaf senescence in rice.The ddg1 mutant displayed dwarfism,short panicles,and delayed leaf senescence.Compared with the wild-type,ddg1 was insensitive to exogenous gibberellins(GA)and brassinolide(BR).DDG1 is expressed in various organs,especially in stems and panicles.Yeast two-hybrid assay,bimolecular fluorescent complementation and luciferase complementation image assay showed that DDG1 interacts with theα-subunit of the heterotrimeric G protein.Disruption of RGA1 resulted in dwarfism,short panicles,and darker-green leaves.Furthermore,we found that ddg1 and the RGA1 mutant was more sensitive to salt treatment,suggesting that DDG1 and RGA1 are involved in regulating salt stress response in rice.Our results show that DDG1/DEP2 regulates plant height and leaf senescence through interacting with RGA1.展开更多
Global warming poses a threat to rice production.Breeding heat-tolerant rice is an effective and economical approach to address this challenge.African rice is a valuable genetic resource for developing heat-tolerant c...Global warming poses a threat to rice production.Breeding heat-tolerant rice is an effective and economical approach to address this challenge.African rice is a valuable genetic resource for developing heat-tolerant crops due to its intricate mechanism for adapting to high temperatures.Oryza longistaminata,a widely distributed wild rice species in Africa,may harbor an even richer gene pool for heat tolerance,which remains untapped.In this study,we identified three heat tolerance QTLs from O.longistaminata at the seedling stage,including novel heat tolerance loci qTT4 and qTT5.Our findings demonstrated that the O.longistaminata alleles for these two QTLs can enhance the heat tolerance of rice seedlings.Remarkably,qTT5 was mapped to a region spanning approximately 287.2 kb,which contains 46 expressing genes.Through the analysis of Gene Ontology and expression differences under heat induction,we identified four candidate genes.Our results lay the foundation for discovering heat tolerance genes underlying O.longistaminata and developing new genetic resources for heat-tolerant rice breeding.展开更多
As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or...As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or QTL from the AA genome wild rice O. longistaminata, which is characterized by tall and robust habit and long tassels and anthers and shows high potential for use in cultivated rice improvement. We constructed a stable BC_(2)F_(20) backcross inbred line(BIL) population of 152 lines from the cross of 9311 × O.longistaminat. Some BILs showed large panicles, large seeds, and strong resistance to rice false smut, bacterial leaf blight, rice blast spot, and brown planthopper. Genomic resequencing showed that the 152 BILs covered about 99.6% of the O. longistaminata genome. QTL mapping with 2432 bin markers revealed 13QTL associated with seven yield traits and eight with resistance to brown planthopper and to four diseases. Of these QTL, 12 for grain yield and 11 for pest and disease resistance are novel in Oryza species.A large-panicle NIL1880 line containing QTL qPB8.1 showed a nearly 50% increase in spikelet number and27.5% in grain yield compared to the recurrent parent 9311. These findings support the potential value of O. longistaminata for cultivated rice improvement.展开更多
Background As demand for high quality animal feed continues to raise,it becomes increasingly important to mini-mize the environmental impact of feed production.An appealing sustainable approach to provide feed fractio...Background As demand for high quality animal feed continues to raise,it becomes increasingly important to mini-mize the environmental impact of feed production.An appealing sustainable approach to provide feed fractions is to use organic residues from agro-food industry.In this regard,volatile fatty acids(VFAs)such as acetic,propionic and butyric acids,derived from bioconversion of organic residues can be used as precursors for production of micro-bial protein with ruminant feed inclusion potential.This study aims to investigate the in vitro digestibility of the Asper-gillus oryzae edible fungal biomass cultivated on VFAs-derived from anaerobic digestion of residues.The produced fungal protein biomass,along with hay clover silage and rapeseed meal were subjected to various in vitro assays using two-stage Tilley and Terry(TT),gas,and bag methods to evaluate and compare its digestibility for application in ruminant feed.Results The produced fungal biomass contained a higher crude protein(CP)(41%–49%)and rather similar neutral detergent fiber(NDF)(41%–56%)compared to rapeseed meal.The rumen in vitro dry matter digestibility(IVDMD)of the fungal biomass in the TT method ranged from 82%to 88%(statistically similar to that of the gas method(72%to 85%)).The IVDMD of fungal biomass were up to 26%and 40%greater than that of hay clover silage and rapeseed meal,respectively.The type of substrate and bag method had pronounced effect on the fermentation products(ammonium-N(NH4+-N),total gas and VFAs).Fungal biomass digestion resulted in the highest release of NH4+-N(340–540 mg/L)and the ratio of acetate to propionate ratio(3.5)among subjected substrates.Conclusion The results indicate that gas method can be used as a reliable predictor for IVDMD as well as fermenta-tion products.Furthermore,the high IVDMD and fermentation product observed for Aspergillus oryzae fungal biomass digestion,suggest that the supplementation of fungal biomass will contribute to improving the rumen digestion by providing necessary nitrogen and energy to the ruminant and microbiota.展开更多
Monogenic lines,which carried 23 genes for blast resistance were tested and used donors to transfer resistance genes by crossing method.The results under blast nursery revealed that 9 genes from 23 genes were suscepti...Monogenic lines,which carried 23 genes for blast resistance were tested and used donors to transfer resistance genes by crossing method.The results under blast nursery revealed that 9 genes from 23 genes were susceptible to highly susceptible under the three locations(Sakha,Gemmeza,and Zarzoura in Egypt);Pia,Pik,Pik-p,Piz-t,Pita,Pi b,Pi,Pi 19 and Pi 20.While,the genes Pii,Pik-s,Pik-h,Pi z,Piz-5,Pi sh,Pi 3,Pi 1,Pi 5,Pi 7,Pi 9,Pi 12,Pikm and Pita-2 were highly resistant at the same locations.Clustering analysis confirmed the results,which divided into two groups;the first one included all the susceptible genes,while the second one included the resistance genes.In the greenhouse test,the reaction pattern of five races produced 100%resistance under artificial inoculation with eight genes showing complete resistance to all isolates.The completely resistant genes:Pii,Pik-s,Piz,Piz-5(=bi2)(t),Pita(=Pi4)(t),Pita,Pi b and Pi1 as well as clustering analysis confirmed the results.In the F1 crosses,the results showed all the 25 crosses were resistant for leaf blast disease under field conditions.While,the results in F2 population showed seven crosses with segregation ratio of 15(R):1(S),two cross gave segregated ratio of 3 R:1 S and one gave 13:3.For the identification of blast resistance genes in the parental lines,the marker K3959,linked to Pik-s gene and the variety IRBLKS-F5 carry this gene,which was from the monogenic line.The results showed that four genotypes;Sakha 105,Sakha 103,Sakha 106 and IRBLKS-F5 were carrying Pik-s gene,while was absent in the Sakha 101,Sakha 104,IRBL5-M,IRBL9-W,IRBLTACP1 and IRBL9-W(R)genotypes.As for Pi 5 gene,the results showed that it was present in Sakha 103 and Sakha 104 varieties and absent in the rest of the genotypes.In addition,Pita-Pita-2 gene was found in the three Egyptian genotypes(Sakha 105,Sakha 101 and Sakha 104)plus IRBLTACP1 monogenetic.In F2 generation,six populations were used to study the inheritance of blast resistance and specific primers to confirm the ratio and identify the resistance genes.However,the ratios in molecular markers were the same of the ratio under field evaluation in the most population studies.These findings would facilitate in breeding programs for gene pyramiding and gene accumulation to produce durable resistance for blast using those genotypes.展开更多
One of the most devastating diseases of rice worldwide is bacterial blight (BLB) caused by Xanthomonas oryzae pv. Oryzae (Xoo). In Benin, Xoo was first described in 2013 on wild rice Oryzae longistaminata. So far, no ...One of the most devastating diseases of rice worldwide is bacterial blight (BLB) caused by Xanthomonas oryzae pv. Oryzae (Xoo). In Benin, Xoo was first described in 2013 on wild rice Oryzae longistaminata. So far, no study has been done on Beninese Xoo strains. We do not know whether the pathogen has already passed into the rice varieties grown, or if they are exposed to other bacteria. Whereas the use of resistant varieties, carrying resistance genes, is the only highly effective and environmentally friendly way to control this disease, no information is available on these Xoo resistance genes in rice varieties grown in Benin apart from the one we recently. This study aims to identify Beninese Xoo strains, causing BLB and screen rice varieties grown in Benin for the main resistance genes. Diseased rice leaves showing typical symptoms of fire blight collected from different rice fields in the three phytogeographic areas of Benin were analyzed by PCR for Xoo-specific sequence identification. Furthermore, seventy-five collected rice accessions were screened to identify xa5, Xa7, xa13, and Xa21 resistance genes to Xoo. The results reveal that Xanthomonas oryzae was identified in two fields in Banikouara and one in Malanville. On the other hand, Sphingomonas sp. has been identified in several other rice fields in Benin. Forty-seven of seventy-five rice accessions examined (62.66%) carried Xoo resistance genes with 3 (4%) and 40 (53.33%) of xa5 and Xa21 respectively. None of the accessions had either Xa7 or xa13 resistance genes. Three accessions possess both xa5 and Xa21 genes. Isogenic lines IRBB60 and IRBB21, supposed to be a positive control, presented a Xoo sensitivity allele. These results indicate that Xoo has moved from the wild rice variety to the cultivated variety in northern Benin and varietal improvement programs must be implemented with varieties having several resistance genes for the efficient response against a possible BLB pandemic in Benin.展开更多
[Objectives]This study was conducted to screen out rice resources resistant to rice blast(Magnaporthe oryzae).[Methods]The qualitative and quantitative resistance of 1659 rice resources from 45 countries and regions t...[Objectives]This study was conducted to screen out rice resources resistant to rice blast(Magnaporthe oryzae).[Methods]The qualitative and quantitative resistance of 1659 rice resources from 45 countries and regions to rice blast were evaluated by disease nursery in upland condition and the test of the spectrum to rice blast isolates.[Results]There were 292 entries which accounted for 17.6%showed high blast resistance(0 and 1 disease scale),68 entries(counted for 4.1%)showed resistance to blast(3 disease scale);and the number of the entries showed intermediate resistance,intermediate susceptible and susceptible were 208(with the corresponding percentage of 12.5%),471(28.4%),620(37.4%)respectively.Among the tested entries,27 entries including BG1222,BL122,BTX,IR37704-131-2-3-2,and LEBONNET had showed broad-spectrum blast resistance with the resistance frequency of higher than 90%,Quantitative resistance evaluation was conducted on some key resources,and 14 entries,of which are BR27,DRAGO,IR100,QINLIUAI、SERIBU GANTANG,YUEXIANGZHAN and so on,showed good quantitative resistances,and 8 entries had higher quantitative resistances than IR36.[Conclusions]This study provides important blast resistance resources for the local rice breeding program and has a significant value for the discovery of new blast resistance genes and its application in the blast resistance breeding.展开更多
In this study, three wheat varieties were tested to determine seed germination and the incidence of Magnaporthe oryzae triticum (MoT). Among these varieties, BARI Gom 24 (Prodip) wheat seed exhibited the highest seed ...In this study, three wheat varieties were tested to determine seed germination and the incidence of Magnaporthe oryzae triticum (MoT). Among these varieties, BARI Gom 24 (Prodip) wheat seed exhibited the highest seed germination rate (93%) but also had the highest incidence (30%) of MoT. To manage blast disease in an ecofriendly manner, seven treatments were employed: T<sub>1</sub> = Control, T<sub>2</sub> = Garlic clove extracts, T<sub>3</sub> = Aloe vera leaf extracts, T<sub>4</sub> = Black cumin seed extracts, T<sub>5</sub> = Neem leaf extracts, T<sub>6</sub> = Nativo 75 WG, and T<sub>7</sub> = Provax 200 WP. The experiment was conducted using a Randomized Complete Block Design (RCBD) layout with three replications using Prodip wheat variety that exhibited highest MoT infection severity based on laboratory analysis among collected varieties. Data were collected on blast disease incidence (%), disease severity, and various growth and yield parameters of wheat. The experiment’s results indicated that among all the treatments, T<sub>7</sub> (Seed treatment with Provax 200 WP) and T<sub>5</sub> (Foliar spraying with Neem leaf extract) performed better in controlling blast disease in wheat. The lowest blast disease incidence (%) was observed with T<sub>7</sub> (Provax 200 WP), with values of 7.86, 9.86, and 10.19 recorded during the milking stage, soft dough stage, and hard dough stage of wheat, respectively. T<sub>5</sub> (Neem leaf extract) also demonstrated a statistically equivalent reduction in blast disease incidence (%). In terms of disease severity, T<sub>7</sub> (Seed treatment with Provax 200 WP) showed the lowest values of 1.03, 1.23, and 1.63 during the milking stage, soft dough stage, and hard dough stage of wheat, respectively. Foliar spraying with neem leaf extract also exhibited similar result as of Provax 200 WP regarding panicle blast severity. As a result of these findings, it can be concluded that T<sub>5</sub> (Neem leaf extract) is recommended as an ecofriendly management approach for blast disease in wheat.展开更多
Most indigenous rice landraces are sensitive to photoperiod during short day seasons,and this sensitivity is more pronounced in indica than in japonica landraces.Attempts to identify photoperiod sensitive(PPS)cultivar...Most indigenous rice landraces are sensitive to photoperiod during short day seasons,and this sensitivity is more pronounced in indica than in japonica landraces.Attempts to identify photoperiod sensitive(PPS)cultivars based on the life history stages of the rice plant,and several models and indices based on phenology and day length have not been precise,and in some cases yield counterfactual inferences.Following the empirical method of traditional Asian rice farmers,the author has developed a robust index,based on the sowing and flowering dates of a large number of landraces grown in different seasons from 2020 to 2023,to contradistinguish PPS from photoperiod insensitive cultivars.Unlike other indices and models of photoperiod sensitivity,the index does not require the presumed duration of different life history stages of the rice plant but relies only on the flowering dates and the number of days till flowering of a rice cultivar sown on different dates to consistently identify photoperiod sensitive cultivars.展开更多
The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three...The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.展开更多
以旱稻田间试验资料为基础,对水稻生长模拟模型ORY ZA 2000模拟旱稻生长进行参数校正和验证,图解和回归分析结果显示ORY ZA 2000模拟旱稻生物量、产量、作物吸氮量的模拟值与观测值基本呈线性关系,模拟效果良好,但对土壤水分的模拟效果...以旱稻田间试验资料为基础,对水稻生长模拟模型ORY ZA 2000模拟旱稻生长进行参数校正和验证,图解和回归分析结果显示ORY ZA 2000模拟旱稻生物量、产量、作物吸氮量的模拟值与观测值基本呈线性关系,模拟效果良好,但对土壤水分的模拟效果欠佳,需做进一步研究。应用校正和验证的结果,结合肥料效应函数原理,对旱稻不同灌溉方式和密度管理下的氮肥经济最佳施肥量做了探讨,初步得出了该地区旱稻栽培氮肥经济最佳施肥量,丰富了作物模拟和节水农业的理论和实践,对以后旱稻发展及栽培管理有一定的参考价值。展开更多
基金supported by grants from the National Natural Science Foundation of China(31401692,31901960,32272513,32001976)the Natural Science Foundation of Fujian Province(2019J01766,2023J011418,2020J05177)+3 种基金Fujian Provincial Science and Technology Key Project(2022NZ030014)External Cooperation Program of Fujian Academy of Agricultural Sciences(DWHZ-2024-23)State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crop Opening Project(SKL2019005)Project of Fujian Provincial Department of Education(JAT190627)。
文摘Avirulence effectors(Avrs),encoded by plant pathogens,can be recognized by plants harboring the corresponding resistance proteins,thereby initiating effector-triggered immunity(ETI).In susceptible plants,however,Avrs can function as effectors,facilitating infection via effector-triggered susceptibility(ETS).Mechanisms of Avr-mediated ETS remain largely unexplored.Here we report that the Magnaporthe oryzae effector Avr-PikD enters rice cells via the canonical cytoplasmic secretion pathway and suppresses rice basal defense.Avr-PikD interacts with an LSD1-like transcriptional activator AKIP30 of rice,and AKIP30 is also a positive regulator of rice immunity,whereas Avr-PikD impedes its nuclear localization and suppresses its transcriptional activity.In summary,M.oryzae delivers Avr-PikD into rice cells to facilitate ETS by inhibiting AKIP30-mediated transcriptional regulation of immune response against M.oryzae.
基金supported by the major science and technology research projects of Guangdong Laboratory for Lingnan Modern Agriculture(NT2021001)the Key Projects of Basic Research and Applied Basic Research of Guangdong Province(2019B030302006)+1 种基金the National Natural Science Foundation of China(32072040,31622041)the National Innovation and Entrepreneurship Training Program for College Students(202110564045)。
文摘Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.
基金supported by the Program for Huaishang Talents,Huai’an Academy of Agricultural Sciences Initiation and Development of Scientific Research Fund for High-Level Introduced Talents(0062019016B)Jiangsu Collaborative Innovation Center of Regional Modern Agriculture&Environmental Protection(HSXT30133)+1 种基金the Jiangsu Qinglan Project,the Hunan Province Natural Science Fund(2019JJ50714)the Student Innovation Program of Jinagsu Province(202110323084Y,202210323029Z).
文摘Many studies have already shown that dwarfism and moderate delayed leaf senescence positively impact rice yield,but the underlying molecular mechanism of dwarfism and leaf senescence remains largely unknown.Here,using map-based cloning,we identified an allele of DEP2,DDG1,which controls plant height and leaf senescence in rice.The ddg1 mutant displayed dwarfism,short panicles,and delayed leaf senescence.Compared with the wild-type,ddg1 was insensitive to exogenous gibberellins(GA)and brassinolide(BR).DDG1 is expressed in various organs,especially in stems and panicles.Yeast two-hybrid assay,bimolecular fluorescent complementation and luciferase complementation image assay showed that DDG1 interacts with theα-subunit of the heterotrimeric G protein.Disruption of RGA1 resulted in dwarfism,short panicles,and darker-green leaves.Furthermore,we found that ddg1 and the RGA1 mutant was more sensitive to salt treatment,suggesting that DDG1 and RGA1 are involved in regulating salt stress response in rice.Our results show that DDG1/DEP2 regulates plant height and leaf senescence through interacting with RGA1.
基金partly granted from the National Natural Science Foundation of China(Grant No.U20A2023)the Joint Open Competitive Project of the Yazhou Bay Laboratory and the China National Seed Company Limitedhe Hubei Hongshan Laboratory,China(Grant No.2021hszd010)。
文摘Global warming poses a threat to rice production.Breeding heat-tolerant rice is an effective and economical approach to address this challenge.African rice is a valuable genetic resource for developing heat-tolerant crops due to its intricate mechanism for adapting to high temperatures.Oryza longistaminata,a widely distributed wild rice species in Africa,may harbor an even richer gene pool for heat tolerance,which remains untapped.In this study,we identified three heat tolerance QTLs from O.longistaminata at the seedling stage,including novel heat tolerance loci qTT4 and qTT5.Our findings demonstrated that the O.longistaminata alleles for these two QTLs can enhance the heat tolerance of rice seedlings.Remarkably,qTT5 was mapped to a region spanning approximately 287.2 kb,which contains 46 expressing genes.Through the analysis of Gene Ontology and expression differences under heat induction,we identified four candidate genes.Our results lay the foundation for discovering heat tolerance genes underlying O.longistaminata and developing new genetic resources for heat-tolerant rice breeding.
基金partly granted from the National Natural Science Foundation of China(U20A2023, 31870322)the Creative Research Groups of the Natural Science Foundation of Hubei Province,China (2020CFA009)the Hubei Hongshan Laboratory (2021hszd010)。
文摘As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or QTL from the AA genome wild rice O. longistaminata, which is characterized by tall and robust habit and long tassels and anthers and shows high potential for use in cultivated rice improvement. We constructed a stable BC_(2)F_(20) backcross inbred line(BIL) population of 152 lines from the cross of 9311 × O.longistaminat. Some BILs showed large panicles, large seeds, and strong resistance to rice false smut, bacterial leaf blight, rice blast spot, and brown planthopper. Genomic resequencing showed that the 152 BILs covered about 99.6% of the O. longistaminata genome. QTL mapping with 2432 bin markers revealed 13QTL associated with seven yield traits and eight with resistance to brown planthopper and to four diseases. Of these QTL, 12 for grain yield and 11 for pest and disease resistance are novel in Oryza species.A large-panicle NIL1880 line containing QTL qPB8.1 showed a nearly 50% increase in spikelet number and27.5% in grain yield compared to the recurrent parent 9311. These findings support the potential value of O. longistaminata for cultivated rice improvement.
基金Open access funding provided by University of Boras
文摘Background As demand for high quality animal feed continues to raise,it becomes increasingly important to mini-mize the environmental impact of feed production.An appealing sustainable approach to provide feed fractions is to use organic residues from agro-food industry.In this regard,volatile fatty acids(VFAs)such as acetic,propionic and butyric acids,derived from bioconversion of organic residues can be used as precursors for production of micro-bial protein with ruminant feed inclusion potential.This study aims to investigate the in vitro digestibility of the Asper-gillus oryzae edible fungal biomass cultivated on VFAs-derived from anaerobic digestion of residues.The produced fungal protein biomass,along with hay clover silage and rapeseed meal were subjected to various in vitro assays using two-stage Tilley and Terry(TT),gas,and bag methods to evaluate and compare its digestibility for application in ruminant feed.Results The produced fungal biomass contained a higher crude protein(CP)(41%–49%)and rather similar neutral detergent fiber(NDF)(41%–56%)compared to rapeseed meal.The rumen in vitro dry matter digestibility(IVDMD)of the fungal biomass in the TT method ranged from 82%to 88%(statistically similar to that of the gas method(72%to 85%)).The IVDMD of fungal biomass were up to 26%and 40%greater than that of hay clover silage and rapeseed meal,respectively.The type of substrate and bag method had pronounced effect on the fermentation products(ammonium-N(NH4+-N),total gas and VFAs).Fungal biomass digestion resulted in the highest release of NH4+-N(340–540 mg/L)and the ratio of acetate to propionate ratio(3.5)among subjected substrates.Conclusion The results indicate that gas method can be used as a reliable predictor for IVDMD as well as fermenta-tion products.Furthermore,the high IVDMD and fermentation product observed for Aspergillus oryzae fungal biomass digestion,suggest that the supplementation of fungal biomass will contribute to improving the rumen digestion by providing necessary nitrogen and energy to the ruminant and microbiota.
基金Authors extend their appreciation to Deanship of Scientific Research,King Faisal University,Saudi Arabia,for supporting this research(NA000112).
文摘Monogenic lines,which carried 23 genes for blast resistance were tested and used donors to transfer resistance genes by crossing method.The results under blast nursery revealed that 9 genes from 23 genes were susceptible to highly susceptible under the three locations(Sakha,Gemmeza,and Zarzoura in Egypt);Pia,Pik,Pik-p,Piz-t,Pita,Pi b,Pi,Pi 19 and Pi 20.While,the genes Pii,Pik-s,Pik-h,Pi z,Piz-5,Pi sh,Pi 3,Pi 1,Pi 5,Pi 7,Pi 9,Pi 12,Pikm and Pita-2 were highly resistant at the same locations.Clustering analysis confirmed the results,which divided into two groups;the first one included all the susceptible genes,while the second one included the resistance genes.In the greenhouse test,the reaction pattern of five races produced 100%resistance under artificial inoculation with eight genes showing complete resistance to all isolates.The completely resistant genes:Pii,Pik-s,Piz,Piz-5(=bi2)(t),Pita(=Pi4)(t),Pita,Pi b and Pi1 as well as clustering analysis confirmed the results.In the F1 crosses,the results showed all the 25 crosses were resistant for leaf blast disease under field conditions.While,the results in F2 population showed seven crosses with segregation ratio of 15(R):1(S),two cross gave segregated ratio of 3 R:1 S and one gave 13:3.For the identification of blast resistance genes in the parental lines,the marker K3959,linked to Pik-s gene and the variety IRBLKS-F5 carry this gene,which was from the monogenic line.The results showed that four genotypes;Sakha 105,Sakha 103,Sakha 106 and IRBLKS-F5 were carrying Pik-s gene,while was absent in the Sakha 101,Sakha 104,IRBL5-M,IRBL9-W,IRBLTACP1 and IRBL9-W(R)genotypes.As for Pi 5 gene,the results showed that it was present in Sakha 103 and Sakha 104 varieties and absent in the rest of the genotypes.In addition,Pita-Pita-2 gene was found in the three Egyptian genotypes(Sakha 105,Sakha 101 and Sakha 104)plus IRBLTACP1 monogenetic.In F2 generation,six populations were used to study the inheritance of blast resistance and specific primers to confirm the ratio and identify the resistance genes.However,the ratios in molecular markers were the same of the ratio under field evaluation in the most population studies.These findings would facilitate in breeding programs for gene pyramiding and gene accumulation to produce durable resistance for blast using those genotypes.
文摘One of the most devastating diseases of rice worldwide is bacterial blight (BLB) caused by Xanthomonas oryzae pv. Oryzae (Xoo). In Benin, Xoo was first described in 2013 on wild rice Oryzae longistaminata. So far, no study has been done on Beninese Xoo strains. We do not know whether the pathogen has already passed into the rice varieties grown, or if they are exposed to other bacteria. Whereas the use of resistant varieties, carrying resistance genes, is the only highly effective and environmentally friendly way to control this disease, no information is available on these Xoo resistance genes in rice varieties grown in Benin apart from the one we recently. This study aims to identify Beninese Xoo strains, causing BLB and screen rice varieties grown in Benin for the main resistance genes. Diseased rice leaves showing typical symptoms of fire blight collected from different rice fields in the three phytogeographic areas of Benin were analyzed by PCR for Xoo-specific sequence identification. Furthermore, seventy-five collected rice accessions were screened to identify xa5, Xa7, xa13, and Xa21 resistance genes to Xoo. The results reveal that Xanthomonas oryzae was identified in two fields in Banikouara and one in Malanville. On the other hand, Sphingomonas sp. has been identified in several other rice fields in Benin. Forty-seven of seventy-five rice accessions examined (62.66%) carried Xoo resistance genes with 3 (4%) and 40 (53.33%) of xa5 and Xa21 respectively. None of the accessions had either Xa7 or xa13 resistance genes. Three accessions possess both xa5 and Xa21 genes. Isogenic lines IRBB60 and IRBB21, supposed to be a positive control, presented a Xoo sensitivity allele. These results indicate that Xoo has moved from the wild rice variety to the cultivated variety in northern Benin and varietal improvement programs must be implemented with varieties having several resistance genes for the efficient response against a possible BLB pandemic in Benin.
基金Supported by Science and Technology Plan Project of Shaoguan(210804164531395)Special Fund for Modern Agricultural Industry Technology System(CARS-01-32,2022KJ105)"14thFive-Year Plan"New Discipline Team Building Project of Guangdong Academy of Agricultural Sciences(202116TD)。
文摘[Objectives]This study was conducted to screen out rice resources resistant to rice blast(Magnaporthe oryzae).[Methods]The qualitative and quantitative resistance of 1659 rice resources from 45 countries and regions to rice blast were evaluated by disease nursery in upland condition and the test of the spectrum to rice blast isolates.[Results]There were 292 entries which accounted for 17.6%showed high blast resistance(0 and 1 disease scale),68 entries(counted for 4.1%)showed resistance to blast(3 disease scale);and the number of the entries showed intermediate resistance,intermediate susceptible and susceptible were 208(with the corresponding percentage of 12.5%),471(28.4%),620(37.4%)respectively.Among the tested entries,27 entries including BG1222,BL122,BTX,IR37704-131-2-3-2,and LEBONNET had showed broad-spectrum blast resistance with the resistance frequency of higher than 90%,Quantitative resistance evaluation was conducted on some key resources,and 14 entries,of which are BR27,DRAGO,IR100,QINLIUAI、SERIBU GANTANG,YUEXIANGZHAN and so on,showed good quantitative resistances,and 8 entries had higher quantitative resistances than IR36.[Conclusions]This study provides important blast resistance resources for the local rice breeding program and has a significant value for the discovery of new blast resistance genes and its application in the blast resistance breeding.
文摘In this study, three wheat varieties were tested to determine seed germination and the incidence of Magnaporthe oryzae triticum (MoT). Among these varieties, BARI Gom 24 (Prodip) wheat seed exhibited the highest seed germination rate (93%) but also had the highest incidence (30%) of MoT. To manage blast disease in an ecofriendly manner, seven treatments were employed: T<sub>1</sub> = Control, T<sub>2</sub> = Garlic clove extracts, T<sub>3</sub> = Aloe vera leaf extracts, T<sub>4</sub> = Black cumin seed extracts, T<sub>5</sub> = Neem leaf extracts, T<sub>6</sub> = Nativo 75 WG, and T<sub>7</sub> = Provax 200 WP. The experiment was conducted using a Randomized Complete Block Design (RCBD) layout with three replications using Prodip wheat variety that exhibited highest MoT infection severity based on laboratory analysis among collected varieties. Data were collected on blast disease incidence (%), disease severity, and various growth and yield parameters of wheat. The experiment’s results indicated that among all the treatments, T<sub>7</sub> (Seed treatment with Provax 200 WP) and T<sub>5</sub> (Foliar spraying with Neem leaf extract) performed better in controlling blast disease in wheat. The lowest blast disease incidence (%) was observed with T<sub>7</sub> (Provax 200 WP), with values of 7.86, 9.86, and 10.19 recorded during the milking stage, soft dough stage, and hard dough stage of wheat, respectively. T<sub>5</sub> (Neem leaf extract) also demonstrated a statistically equivalent reduction in blast disease incidence (%). In terms of disease severity, T<sub>7</sub> (Seed treatment with Provax 200 WP) showed the lowest values of 1.03, 1.23, and 1.63 during the milking stage, soft dough stage, and hard dough stage of wheat, respectively. Foliar spraying with neem leaf extract also exhibited similar result as of Provax 200 WP regarding panicle blast severity. As a result of these findings, it can be concluded that T<sub>5</sub> (Neem leaf extract) is recommended as an ecofriendly management approach for blast disease in wheat.
文摘Most indigenous rice landraces are sensitive to photoperiod during short day seasons,and this sensitivity is more pronounced in indica than in japonica landraces.Attempts to identify photoperiod sensitive(PPS)cultivars based on the life history stages of the rice plant,and several models and indices based on phenology and day length have not been precise,and in some cases yield counterfactual inferences.Following the empirical method of traditional Asian rice farmers,the author has developed a robust index,based on the sowing and flowering dates of a large number of landraces grown in different seasons from 2020 to 2023,to contradistinguish PPS from photoperiod insensitive cultivars.Unlike other indices and models of photoperiod sensitivity,the index does not require the presumed duration of different life history stages of the rice plant but relies only on the flowering dates and the number of days till flowering of a rice cultivar sown on different dates to consistently identify photoperiod sensitive cultivars.
基金support of the National 863 Project (2012AA021601)the New Seedling program for graduate students of Zhejiang Province (2012R409012)
文摘The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.
文摘以旱稻田间试验资料为基础,对水稻生长模拟模型ORY ZA 2000模拟旱稻生长进行参数校正和验证,图解和回归分析结果显示ORY ZA 2000模拟旱稻生物量、产量、作物吸氮量的模拟值与观测值基本呈线性关系,模拟效果良好,但对土壤水分的模拟效果欠佳,需做进一步研究。应用校正和验证的结果,结合肥料效应函数原理,对旱稻不同灌溉方式和密度管理下的氮肥经济最佳施肥量做了探讨,初步得出了该地区旱稻栽培氮肥经济最佳施肥量,丰富了作物模拟和节水农业的理论和实践,对以后旱稻发展及栽培管理有一定的参考价值。
