1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain ...1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain weight were mapped through sequencing-based genotyping of 150 rice recombinant inbred lines （RILs）. In this study, we validated the effects of four QTLs from Nipponbare using chromosome segment substitution lines （CSSLs）, and pyramided eight grain yield related QTLs. The new lines containing the eight QTLs with positive effects showed increased panicle and spikelet size as compared with the parent variety 93-11. We further proposed a novel pyramid breeding scheme based on marker-assistant and phenotype selection （MAPS）. This scheme allowed pyramiding of as many as 24 QTLs at a single hybridization without massive cross work. This study provided insights into the molecular basis of rice grain yield for direct wealth for high-yielding rice breeding.展开更多
Wheat(Triticum aestivum)is among the most important staple crops for safeguarding the food security of the growing world population.To bridge the gap between genebank diversity and breeding programs,we developed an ad...Wheat(Triticum aestivum)is among the most important staple crops for safeguarding the food security of the growing world population.To bridge the gap between genebank diversity and breeding programs,we developed an advanced backcross-nested association mapping plus inter-crossed population(AB-NAMIC)by crossing three popular wheat cultivars as recurrent founders to 20 germplasm lines from a mini core collection.Selective backcrossing combined with selection against undesirable traits and extensive crossing within and between sub-populations created new opportunities to detect unknown genes and increase the frequency of beneficial alleles in the AB-NAMIC population.We performed phenotyping of 590 AB-NAMIC lines and a natural panel of 476 cultivars for six consecutive growing seasons and genotyped these 1066 lines with a 660K SNP array.Genome-wide association studies of both panels for plant development and yield traits demonstrated improved power to detect rare alleles and loci with medium genetic effects in AB-NAMIC.Notably,genome-wide association studies in AB-NAMIC detected the candidate gene TaSWEET6-7B(TraesCS7B03G1216700),which has high homology to the rice SWEET6b gene and exerts strong effects on adaptation and yield traits.The commercial release of two derived AB-NAMIC lines attests to its direct applicability in wheat improvement.Valuable information on genome-wide association studymapping,candidate genes,and their haplotypes for breeding traits are available through WheatGAB.Our research provides an excellent framework for fast-tracking exploration and accumulation of beneficial alleles stored in genebanks.展开更多
Rice(Oryza sativa L.)stands as the most significantly influential food crop in the developing world,with its total production and yield stability affected by environmental stress.Drought stress impacts about 45%of the...Rice(Oryza sativa L.)stands as the most significantly influential food crop in the developing world,with its total production and yield stability affected by environmental stress.Drought stress impacts about 45%of the world’s rice area,affecting plants at molecular,biochemical,physiological,and phenotypic levels.The conventional breeding method,predominantly employing single pedigree selection,has been widely utilized in breeding numerous drought-tolerant rice varieties since the Green Revolution.With rapid progress in plant molecular biology,hundreds of drought-tolerant QTLs/genes have been identified and tested in rice crops under both indoor and field conditions.Several genes have been introgressed into elite germplasm to develop commercially accepted drought-tolerant varieties,resulting in the development of several drought-tolerant rice varieties through marker-assisted selection and genetically engineered approaches.This review provides up-to-date information on proof-of-concept genes and breeding methods in the molecular breeding era,offering guidance for rice breeders to develop drought-tolerant rice varieties.展开更多
Sex determination in plants gives rise to unisexual flowers. A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in p...Sex determination in plants gives rise to unisexual flowers. A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in plants and allow researchers and farmers to harness heterosis. Androecious cucumber(Cucumis sativus L.) plants can be used as the male parent when planted alongside a gynoecious line to produce heterozygous seeds, thus reducing the cost of seed production. The isolation and characterization of additional androecious genotypes in varied backgrounds will increase the pool of available germplasm for breeding. Here, we discovered an androecious mutant in a previously generated ethyl methanesulfonate(EMS)-mutagenized library of the cucumber inbred line ‘406’. Genetic analysis, whole-genome resequencing, and molecular marker-assisted verification demonstrated that a nonsynonymous mutation in the ethylene biosynthetic gene 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 11(ACS11) conferred androecy. The mutation caused an amino acid change from serine(Ser) to phenylalanine(Phe) at position 301(S301F). In vitro enzyme activity assays revealed that this S301F mutation leads to a complete loss of enzymatic activity. This study provides a new germplasm for use in cucumber breeding as the androecious male parent, and it offers new insights into the catalytic mechanism of ACS enzymes.展开更多
Fusarium head blight(FHB)is one of the most detrimental wheat diseases which greatly decreases the yield and grain quality,especially in the middle and lower reaches of the Yangtze River of China.Fhb1 and Fhb2 are two...Fusarium head blight(FHB)is one of the most detrimental wheat diseases which greatly decreases the yield and grain quality,especially in the middle and lower reaches of the Yangtze River of China.Fhb1 and Fhb2 are two major resistance loci against Fusarium graminearum.Yangmai 15(YM15)is one of the most popular varieties in the middle and lower reaches of the Yangtze River,and it has good weak gluten characters but poor resistance to FHB.Here we used Fhb1 and Fhb2 to improve the FHB resistance of YM15 by a molecular marker-assisted selection(MAS)backcrossing strategy.The selection of agronomic traits was performed for each generation.We successfully selected seven introgressed lines which carry homozygous Fhb1 and Fhb2 with significantly higher FHB resistance than the recurrent parent YM15.Three of the introgressed lines had agronomic and quality characters that were similar to YM15.This study demonstrates that the pyramiding of Fhb1 and Fhb2 could significantly improve the FHB resistance in wheat using the MAS approach.展开更多
Whole-genome genotyping methods are important for breeding.However,it has been challenging to develop a robust method for simultaneous foreground and background genotyping that can easily be adapted to different genes...Whole-genome genotyping methods are important for breeding.However,it has been challenging to develop a robust method for simultaneous foreground and background genotyping that can easily be adapted to different genes and species.In our study,we accidently discovered that in adapter ligation-mediated PCR,the amplification by primertemplate mismatched annealing(PTMA)along the genome could generate thousands of stable PCR products.Based on this observation,we consequently developed a novel method for simultaneous foreground and background integrated genotyping by sequencing(FBI-seq)using one specific primer,in which foreground genotyping is performed by primer-template perfect annealing(PTPA),while background genotyping employs PTMA.Unlike DNA arrays,multiple PCR,or genome target enrichments,FBI-seq requires little preliminary work for primer design and synthesis,and it is easily adaptable to different foreground genes and species.FBI-seq therefore provides a prolific,robust,and accurate method for simultaneous foreground and background genotyping to facilitate breeding in the postgenomics era.展开更多
The production and productivity of rice has been challenged due to biotic and abiotic factors.Bacterial blight(BB)disease,caused by Xanthomonas oryzae pv.oryzae,is one of the important biotic stress factors,which redu...The production and productivity of rice has been challenged due to biotic and abiotic factors.Bacterial blight(BB)disease,caused by Xanthomonas oryzae pv.oryzae,is one of the important biotic stress factors,which reduces rice production by 20%-50%.The deployment of host plant resistance is the most preferred strategy for management of BB disease,and breeding disease resistant varieties remains a very economical and effective option.However,it is difficult to develop rice varieties with durable broad-spectrum resistance against BB using conventional approaches alone.Modern biotechnological tools,particularly the deployment of molecular markers,have facilitated the cloning,characterization and introgression of BB resistance genes into elite varieties.At least 46 BB resistance genes have been identified and mapped from diverse sources till date.Among these,11 genes have been cloned and characterized.Marker-assisted breeding remains the most efficient approach to improve BB resistance by introducing two or more resistance genes into target varieties.Among the identified genes,xa5,xa13 and Xa21 are being widely used in marker-assisted breeding and more than 70 rice varieties or hybrid rice parental lines have been improved for their BB resistance alone or in combination with genes/QTLs conferring tolerance to other stress.We review the developments related to identification and utilization of various resistance genes to develop BB resistant rice varieties through marker-assisted breeding.展开更多
Drought is one of the major abiotic threat to rice production in the context of climate change.Super Basmati is an elite,fine grain basmati rice variety grown in Punjab,Pakistan.Due to drought sensitive in nature,its ...Drought is one of the major abiotic threat to rice production in the context of climate change.Super Basmati is an elite,fine grain basmati rice variety grown in Punjab,Pakistan.Due to drought sensitive in nature,its yield has been facing an alarming situation in production because of gradual decrease in irrigated water for a couple of years.Three reported novel QTLs for drought tolerance were selected for incorporation into Super Basmati by employing marker assisted selection strategy.IR55419-04 with novel QTLs was used as a donor parent.Foreground selection was performed by applying PCR based QTL linked SSR markers followed by recombinant selection by using 2-4 flanking markers.Background selection was exercised by using polymorphic SSR markers for maximum genome recovery of the Super Basmati.The individuals homozygous at the target QTLs and with maximum background of Super Basmati at the rest of the non-target genome was selected for evaluation of drought tolerance.Under drought stress conditions,the yields of all introgressed lines(ILs)were 44.2%-125.7%higher than recurrent parent.Six superior ILs that are drought tolerant and very similar to Super Basmati in terms of agronomic and grain quality traits are marked for release as drought-tolerant varieties in arid regions or for use in breeding programs of high grain quality and drought-tolerant parents.展开更多
基金supported by the Ministry of Science and Technology(Grant No. 2011 CB 100205)the Ministry of Agriculture of China (Grant Nos.2011ZX08001-004 and 2011ZX08009-002)the National Natural Science Foundation of China(Grant No. 31121063)
文摘1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain weight were mapped through sequencing-based genotyping of 150 rice recombinant inbred lines （RILs）. In this study, we validated the effects of four QTLs from Nipponbare using chromosome segment substitution lines （CSSLs）, and pyramided eight grain yield related QTLs. The new lines containing the eight QTLs with positive effects showed increased panicle and spikelet size as compared with the parent variety 93-11. We further proposed a novel pyramid breeding scheme based on marker-assistant and phenotype selection （MAPS）. This scheme allowed pyramiding of as many as 24 QTLs at a single hybridization without massive cross work. This study provided insights into the molecular basis of rice grain yield for direct wealth for high-yielding rice breeding.
基金supported by the National Key Research and Development Program of China(2022YFD1201503 and 2016YFD0100302)the National Major Agricultural Science and Technology Project(NK2022060101).
文摘Wheat(Triticum aestivum)is among the most important staple crops for safeguarding the food security of the growing world population.To bridge the gap between genebank diversity and breeding programs,we developed an advanced backcross-nested association mapping plus inter-crossed population(AB-NAMIC)by crossing three popular wheat cultivars as recurrent founders to 20 germplasm lines from a mini core collection.Selective backcrossing combined with selection against undesirable traits and extensive crossing within and between sub-populations created new opportunities to detect unknown genes and increase the frequency of beneficial alleles in the AB-NAMIC population.We performed phenotyping of 590 AB-NAMIC lines and a natural panel of 476 cultivars for six consecutive growing seasons and genotyped these 1066 lines with a 660K SNP array.Genome-wide association studies of both panels for plant development and yield traits demonstrated improved power to detect rare alleles and loci with medium genetic effects in AB-NAMIC.Notably,genome-wide association studies in AB-NAMIC detected the candidate gene TaSWEET6-7B(TraesCS7B03G1216700),which has high homology to the rice SWEET6b gene and exerts strong effects on adaptation and yield traits.The commercial release of two derived AB-NAMIC lines attests to its direct applicability in wheat improvement.Valuable information on genome-wide association studymapping,candidate genes,and their haplotypes for breeding traits are available through WheatGAB.Our research provides an excellent framework for fast-tracking exploration and accumulation of beneficial alleles stored in genebanks.
基金the National Natural Science Foundation of China(Grant No.31900361).
文摘Rice(Oryza sativa L.)stands as the most significantly influential food crop in the developing world,with its total production and yield stability affected by environmental stress.Drought stress impacts about 45%of the world’s rice area,affecting plants at molecular,biochemical,physiological,and phenotypic levels.The conventional breeding method,predominantly employing single pedigree selection,has been widely utilized in breeding numerous drought-tolerant rice varieties since the Green Revolution.With rapid progress in plant molecular biology,hundreds of drought-tolerant QTLs/genes have been identified and tested in rice crops under both indoor and field conditions.Several genes have been introgressed into elite germplasm to develop commercially accepted drought-tolerant varieties,resulting in the development of several drought-tolerant rice varieties through marker-assisted selection and genetically engineered approaches.This review provides up-to-date information on proof-of-concept genes and breeding methods in the molecular breeding era,offering guidance for rice breeders to develop drought-tolerant rice varieties.
基金supported by the National Key Research and Development Program of China (2018YFD1000803)the National Natural Science Foundation of China (31701933 and 32002036)the Shandong Provincial Natural Science Foundation, China (ZR2020QC157)。
文摘Sex determination in plants gives rise to unisexual flowers. A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in plants and allow researchers and farmers to harness heterosis. Androecious cucumber(Cucumis sativus L.) plants can be used as the male parent when planted alongside a gynoecious line to produce heterozygous seeds, thus reducing the cost of seed production. The isolation and characterization of additional androecious genotypes in varied backgrounds will increase the pool of available germplasm for breeding. Here, we discovered an androecious mutant in a previously generated ethyl methanesulfonate(EMS)-mutagenized library of the cucumber inbred line ‘406’. Genetic analysis, whole-genome resequencing, and molecular marker-assisted verification demonstrated that a nonsynonymous mutation in the ethylene biosynthetic gene 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 11(ACS11) conferred androecy. The mutation caused an amino acid change from serine(Ser) to phenylalanine(Phe) at position 301(S301F). In vitro enzyme activity assays revealed that this S301F mutation leads to a complete loss of enzymatic activity. This study provides a new germplasm for use in cucumber breeding as the androecious male parent, and it offers new insights into the catalytic mechanism of ACS enzymes.
基金supported by the National Natural Science Foundation of China(31901544 and 2071999)the National Key Research and Development Program of China(2017YFD0100801)。
文摘Fusarium head blight(FHB)is one of the most detrimental wheat diseases which greatly decreases the yield and grain quality,especially in the middle and lower reaches of the Yangtze River of China.Fhb1 and Fhb2 are two major resistance loci against Fusarium graminearum.Yangmai 15(YM15)is one of the most popular varieties in the middle and lower reaches of the Yangtze River,and it has good weak gluten characters but poor resistance to FHB.Here we used Fhb1 and Fhb2 to improve the FHB resistance of YM15 by a molecular marker-assisted selection(MAS)backcrossing strategy.The selection of agronomic traits was performed for each generation.We successfully selected seven introgressed lines which carry homozygous Fhb1 and Fhb2 with significantly higher FHB resistance than the recurrent parent YM15.Three of the introgressed lines had agronomic and quality characters that were similar to YM15.This study demonstrates that the pyramiding of Fhb1 and Fhb2 could significantly improve the FHB resistance in wheat using the MAS approach.
基金supported by the National Natural Science Foundation of China(31970379 and 32172086)the Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC-MCP)+3 种基金the National Key R&D Program of China (ZZ202001)the R&D program of Shenzhen (KCXFZ20211020164207012)the R&D program in key areas of Guangdong Province (2021B0707010006)the Science and Technology Planning Project of Guangdong Province (2022B0202060002)。
文摘Whole-genome genotyping methods are important for breeding.However,it has been challenging to develop a robust method for simultaneous foreground and background genotyping that can easily be adapted to different genes and species.In our study,we accidently discovered that in adapter ligation-mediated PCR,the amplification by primertemplate mismatched annealing(PTMA)along the genome could generate thousands of stable PCR products.Based on this observation,we consequently developed a novel method for simultaneous foreground and background integrated genotyping by sequencing(FBI-seq)using one specific primer,in which foreground genotyping is performed by primer-template perfect annealing(PTPA),while background genotyping employs PTMA.Unlike DNA arrays,multiple PCR,or genome target enrichments,FBI-seq requires little preliminary work for primer design and synthesis,and it is easily adaptable to different foreground genes and species.FBI-seq therefore provides a prolific,robust,and accurate method for simultaneous foreground and background genotyping to facilitate breeding in the postgenomics era.
文摘The production and productivity of rice has been challenged due to biotic and abiotic factors.Bacterial blight(BB)disease,caused by Xanthomonas oryzae pv.oryzae,is one of the important biotic stress factors,which reduces rice production by 20%-50%.The deployment of host plant resistance is the most preferred strategy for management of BB disease,and breeding disease resistant varieties remains a very economical and effective option.However,it is difficult to develop rice varieties with durable broad-spectrum resistance against BB using conventional approaches alone.Modern biotechnological tools,particularly the deployment of molecular markers,have facilitated the cloning,characterization and introgression of BB resistance genes into elite varieties.At least 46 BB resistance genes have been identified and mapped from diverse sources till date.Among these,11 genes have been cloned and characterized.Marker-assisted breeding remains the most efficient approach to improve BB resistance by introducing two or more resistance genes into target varieties.Among the identified genes,xa5,xa13 and Xa21 are being widely used in marker-assisted breeding and more than 70 rice varieties or hybrid rice parental lines have been improved for their BB resistance alone or in combination with genes/QTLs conferring tolerance to other stress.We review the developments related to identification and utilization of various resistance genes to develop BB resistant rice varieties through marker-assisted breeding.
基金We thank Higher Education Commission of Pakistan and Green Super Rice Project a Component of Productivity Enhancement of Rice(PSDP No.0754),Pakistan for providing financial support.
文摘Drought is one of the major abiotic threat to rice production in the context of climate change.Super Basmati is an elite,fine grain basmati rice variety grown in Punjab,Pakistan.Due to drought sensitive in nature,its yield has been facing an alarming situation in production because of gradual decrease in irrigated water for a couple of years.Three reported novel QTLs for drought tolerance were selected for incorporation into Super Basmati by employing marker assisted selection strategy.IR55419-04 with novel QTLs was used as a donor parent.Foreground selection was performed by applying PCR based QTL linked SSR markers followed by recombinant selection by using 2-4 flanking markers.Background selection was exercised by using polymorphic SSR markers for maximum genome recovery of the Super Basmati.The individuals homozygous at the target QTLs and with maximum background of Super Basmati at the rest of the non-target genome was selected for evaluation of drought tolerance.Under drought stress conditions,the yields of all introgressed lines(ILs)were 44.2%-125.7%higher than recurrent parent.Six superior ILs that are drought tolerant and very similar to Super Basmati in terms of agronomic and grain quality traits are marked for release as drought-tolerant varieties in arid regions or for use in breeding programs of high grain quality and drought-tolerant parents.
