Liliangyou 3822 is a novel indica hybrid rice variety that exhibits disease resistance,high yield,lodging resistance,and late maturity.It employs a self-selected two-line sterile line,Li 38S,and a self-selected restor...Liliangyou 3822 is a novel indica hybrid rice variety that exhibits disease resistance,high yield,lodging resistance,and late maturity.It employs a self-selected two-line sterile line,Li 38S,and a self-selected restorer line,R22.This variety was subjected to a regional test of indica late-maturing groups in the middle and lower reaches of the Yangtze River in 2020.The results demonstrated that the average yield of the variety was 9.95 t/hm 2,which was 10.67%higher than that of the control Fengliangyou 4,indicating a highly significant yield increase.In the continuous test in 2021,the average yield was 9.74 t/hm 2,representing a 6.52%increase over the control,which also exhibited a significant increase.Finally,the average yield of the two years regional test was 9.84 t/hm 2,which was 8.58%higher than that of the control.In the 2021 production test,the average yield of the variety was 9.32 t/hm 2,which was 12.19%higher than that of the control,indicating a remarkably significant yield increase.In 2022,the variety was validated by the National Crop Variety Approval Committee(GSD 20220143).展开更多
With global warming and frequent occurrence of severe weather,rice diseases are also on the rise.Therefore,the breeding of new rice varieties with disease resistance is still the breeding direction for rice breeding e...With global warming and frequent occurrence of severe weather,rice diseases are also on the rise.Therefore,the breeding of new rice varieties with disease resistance is still the breeding direction for rice breeding experts."Liangyou 7968"is a new hybrid rice combination with double resistance to bacterial blight and rice blast.This paper introduced the breeding process,characteristics,high-yielding cultivation techniques and high-yielding seed production technical regulations for Liangyou 7968.展开更多
The hybrid cotton varieties of Hanza 160 and Hanza 1692 were bred by reciprocal crosses between Han 5158 and Han 333 in Hainan and Hebei for several years. Both varieties had the characters of high yield, high quality...The hybrid cotton varieties of Hanza 160 and Hanza 1692 were bred by reciprocal crosses between Han 5158 and Han 333 in Hainan and Hebei for several years. Both varieties had the characters of high yield, high quality and disease resistance. Hanza 160 and Hanza 1692 were approved by Hebei Crop Variety Approval Committee in 2013 and 2016, respectively.展开更多
This paper outlines the physiological responses of plants to pathogenic microbial infection and pest feeding stress,as well as the resistance characteristics of plants to diseases and pests,and proposes new directions...This paper outlines the physiological responses of plants to pathogenic microbial infection and pest feeding stress,as well as the resistance characteristics of plants to diseases and pests,and proposes new directions for future research on crop resistance to diseases and pests.The objective of this paper is to provide a reference framework for the breeding of crops with enhanced resistance to diseases and pests,the utilization of natural immunity in crops,and the efficient prevention and control of diseases and pests.This framework is intended to facilitate the healthy and sustainable development of the agricultural industry.展开更多
Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have
PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T...PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T3,and T4)in transgenic maize germplasms(S3002 and 349)containing the bivalent genes(insect resistance gene Cry1Ab13-1 and disease resistance gene NPR1)and their corresponding wild type.Results indicated that the target genes Cry1Ab13-1 and NPR1 were successfully transferred into both germplasms through tested generations;q-PCR confirmed the expression of Cry1Ab13-1 and NPR1 genes in roots,stems,and leaves of tested maize plants.In addition,S3002 and 349 bivalent gene-transformed lines exhibited resistance to large leaf spots and corn borer in the field evaluation compared to the wild type.Our study confirmed that Cry1Ab13-1 and NPR1 bivalent genes enhanced the resistance against maize borer and large leaf spot disease and can stably inherit.These findings could be exploited for improving other cultivated maize varieties.展开更多
Maize(Zea mays L.)is an indispensable crop worldwide for food,feed,and bioenergy production.Fusarium verticillioides(F.verticillioides)is a widely distributed phytopathogen and incites multiple destructive diseases in...Maize(Zea mays L.)is an indispensable crop worldwide for food,feed,and bioenergy production.Fusarium verticillioides(F.verticillioides)is a widely distributed phytopathogen and incites multiple destructive diseases in maize:seedling blight,stalk rot,ear rot,and seed rot.As a soil-,seed-,and airborne pathogen,F.verticillioides can survive in soil or plant residue and systemically infect maize via roots,contaminated seed,silks,or external wounds,posing a severe threat to maize production and quality.Infection triggers complex immune responses:induction of defense-response genes,changes in reactive oxygen species,plant hormone levels and oxylipins,and alterations in secondary metabolites such as flavonoids,phenylpropanoids,phenolic compounds,and benzoxazinoid defense compounds.Breeding resistant maize cultivars is the preferred approach to reducing F.verticillioides infection and mycotoxin contamination.Reliable phenotyping systems are prerequisites for elucidating the genetic structure and molecular mechanism of maize resistance to F.verticillioides.Although many F.verticillioides resistance genes have been identified by genome-wide association study,linkage analysis,bulkedsegregant analysis,and various omics technologies,few have been functionally validated and applied in molecular breeding.This review summarizes research progress on the infection cycle of F.verticillioides in maize,phenotyping evaluation systems for F.verticillioides resistance,quantitative trait loci and genes associated with F.verticillioides resistance,and molecular mechanisms underlying maize defense against F.verticillioides,and discusses potential avenues for molecular design breeding to improve maize resistance to F.verticillioides.展开更多
Over the past years, infectious disease has caused enormous economic loss in pig industry. Among the pathogens, gram negative bacteria not only cause inflammation, but also cause different diseases and make the pigs m...Over the past years, infectious disease has caused enormous economic loss in pig industry. Among the pathogens, gram negative bacteria not only cause inflammation, but also cause different diseases and make the pigs more susceptible to virus infection. Vaccination, medication and elimination of sick pigs are major strategies of controlling disease. Genetic methods, such as selection of disease resistance in the pig, have not been widely used. Recently, the completion of the porcine whole genome sequencing has provided powerful tools to identify the genome regions that harboring genes controlling disease or immunity. Immunogenornics, which combines DNA variations, transcriptorne, immune response, and QTL mapping data to illustrate the interactions between pathogen and host immune system, will be an effective genomics tool for identification of disease resistance genes in pigs. These genes will be potential targets for disease resistance in breeding programs. This paper reviewed the progress of disease resistance study in the pig focusing on Gram-negative bacilli. Major porcine Gram-negative bacilli and diseases, suggested candidate genes/pathways against porcine Gram-negative bacilli, and distributions of QTLs for immune capacity on pig chromosomes were summarized. Some tools for immunogenomics research were described. We conclude that integration of sequencing, whole genome associations, functional genomics studies, and immune response information is necessary to illustrate molecular mechanisms and key genes in disease resistance.展开更多
Jiyou 360, a new hybrid rice combination, was developed by the Guangdong Jindao Seed Co., Ltd. and Rice Research Institute of Guangdong Academy of Agricultural Sciences with restorers Guanghui 360 and Jifeng A as the ...Jiyou 360, a new hybrid rice combination, was developed by the Guangdong Jindao Seed Co., Ltd. and Rice Research Institute of Guangdong Academy of Agricultural Sciences with restorers Guanghui 360 and Jifeng A as the parents. This combination is highly resistant to blast, and it was approved as a new variety by the Guangdong Provincial Crop Variety Approval Committee in February 2016, with approval number of YSD 2016015, Jiyou 360 is suitable for planting in Guangdong Province as early and late rice.展开更多
This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and ...This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and countermeasures for solving.展开更多
Rapeseed is an important oil crop with high economic value.It can be used not only as edible oil and livestock feed,but also in medicine,industry and tourism.Sclerotium sclerotiorum is a necrotrophic fungal pathogen t...Rapeseed is an important oil crop with high economic value.It can be used not only as edible oil and livestock feed,but also in medicine,industry and tourism.Sclerotium sclerotiorum is a necrotrophic fungal pathogen that harms the yield and quality of rape.This article mainly summarizes the research status of S.sclerotiorum from three aspects:the biological characteristics,infection mode,process and disease resistance breeding of S.sclerotiorum,and summarizes the future research directions of antibacterial sclerotium on rape,to provide reference for future research on sclerotinia.展开更多
Eggplant phomopsis rot was summarized from the aspects of distribution and damage, pathogen identification and pathogenicity differentiation, and disease-resistant breeding. Furthermore, some existing problems and res...Eggplant phomopsis rot was summarized from the aspects of distribution and damage, pathogen identification and pathogenicity differentiation, and disease-resistant breeding. Furthermore, some existing problems and research directions in future was also discussed.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
In this paper a general introduction is given to research advances in genetics improvement and breeding of Chinese aspen (Populus davidiana Dode) in China. This introduction includes natural distribution and collectio...In this paper a general introduction is given to research advances in genetics improvement and breeding of Chinese aspen (Populus davidiana Dode) in China. This introduction includes natural distribution and collection, conservation, gene diversity, provenance trial, crossing breeding, vegetative propagation and disease resistant etc. Based on the current situation of forest tree breeding in China, some strategic suggestions concerning the future development of Chinese aspen genetics improvement in China are presented, taking into consideration the existing domestic demands of forestry production and international trends in forest tree breeding.展开更多
The development of durable and broad-spectrum resistance is an economical and eco-friendly approach to control crop diseases for sustainable agricultural production. Emerging knowledge of the molecular basis of pathog...The development of durable and broad-spectrum resistance is an economical and eco-friendly approach to control crop diseases for sustainable agricultural production. Emerging knowledge of the molecular basis of pathogenesis and plant–pathogen interactions has contributed to the development of novel pathogen-informed breeding strategies beyond the limits imposed by conventional breeding. Here,we review the current status of pathogen-assisted resistance-related gene cloning. We also describe how pathogen effector proteins can be used to identify resistance resources and to inform cultivar deployment. Finally, we summarize the main approaches for pathogen-directed plant improvement,including transgenesis and genome editing. Thus, we describe the emerging role of pathogen-related studies in the breeding of disease-resistant varieties, and propose innovative pathogen-informed strategies for future applications.展开更多
The quantitative resistance gene pi21 from Sensho was introgressed to an indica breeding line IR63307-4B-13-2,a pyramiding line IRBB4/5/13/21,and a tropical japonica line Kinandang Patong by marker-assisted backcrossi...The quantitative resistance gene pi21 from Sensho was introgressed to an indica breeding line IR63307-4B-13-2,a pyramiding line IRBB4/5/13/21,and a tropical japonica line Kinandang Patong by marker-assisted backcrossing.A total of 192 improved lines at the BC4F3 and BC4F4 generations were developed and confirmed to have the gene introgression via genotyping using a pi21-specific InDel marker.Thirteen randomly selected improved lines,representing all the three genetic backgrounds,demonstrated resistance against leaf blast composites in the field and a broader spectrum resistance against individual isolates compared to the recurrent parents in the glasshouse.Specifically,the tested lines exhibited pi21-acquired resistance against 11 leaf blast isolates that elicited susceptible reactions from the recurrent parents.All the tested lines maintained a comparative heading date,and similar or improved panicle length,number of primary branches per panicle and number of total grains per panicle relative to the recurrent parents.The physical grain characteristics of the recurrent parents were also maintained in the 13 lines tested,although variability in the amylose content and chalkiness degree was observed.The successful marker-assisted introgression of pi21 in diverse genetic backgrounds and the resulting broader spectrum resistance of improved lines against leaf blast indicate the potential of pi21 for deployment in cultivars grown across other rice growing regions in Asia.展开更多
文摘Liliangyou 3822 is a novel indica hybrid rice variety that exhibits disease resistance,high yield,lodging resistance,and late maturity.It employs a self-selected two-line sterile line,Li 38S,and a self-selected restorer line,R22.This variety was subjected to a regional test of indica late-maturing groups in the middle and lower reaches of the Yangtze River in 2020.The results demonstrated that the average yield of the variety was 9.95 t/hm 2,which was 10.67%higher than that of the control Fengliangyou 4,indicating a highly significant yield increase.In the continuous test in 2021,the average yield was 9.74 t/hm 2,representing a 6.52%increase over the control,which also exhibited a significant increase.Finally,the average yield of the two years regional test was 9.84 t/hm 2,which was 8.58%higher than that of the control.In the 2021 production test,the average yield of the variety was 9.32 t/hm 2,which was 12.19%higher than that of the control,indicating a remarkably significant yield increase.In 2022,the variety was validated by the National Crop Variety Approval Committee(GSD 20220143).
基金Supported by Anhui Provincial Key Research and Development Project(2023n06020013).
文摘With global warming and frequent occurrence of severe weather,rice diseases are also on the rise.Therefore,the breeding of new rice varieties with disease resistance is still the breeding direction for rice breeding experts."Liangyou 7968"is a new hybrid rice combination with double resistance to bacterial blight and rice blast.This paper introduced the breeding process,characteristics,high-yielding cultivation techniques and high-yielding seed production technical regulations for Liangyou 7968.
基金Supported by the Key Technology R&D Program of Hebei Province(16226307D-4)
文摘The hybrid cotton varieties of Hanza 160 and Hanza 1692 were bred by reciprocal crosses between Han 5158 and Han 333 in Hainan and Hebei for several years. Both varieties had the characters of high yield, high quality and disease resistance. Hanza 160 and Hanza 1692 were approved by Hebei Crop Variety Approval Committee in 2013 and 2016, respectively.
基金Supported by Science and Technology Innovation Guidance Project of Zhaoqing in 2023(2023040308006)Major Science and Technology Special Project of Yunnan Province(202202AE090036)+1 种基金Open Project of Yunnan State Key Laboratory for Conservation and Utilization of Bio-Resources(gzkf2022004)Innovation Platform Construction Project of Zhaoqing University in 2024(202413004).
文摘This paper outlines the physiological responses of plants to pathogenic microbial infection and pest feeding stress,as well as the resistance characteristics of plants to diseases and pests,and proposes new directions for future research on crop resistance to diseases and pests.The objective of this paper is to provide a reference framework for the breeding of crops with enhanced resistance to diseases and pests,the utilization of natural immunity in crops,and the efficient prevention and control of diseases and pests.This framework is intended to facilitate the healthy and sustainable development of the agricultural industry.
文摘Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have
基金supported by the National Key Research and Development Program of China(2019YFD1002603-1)。
文摘PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T3,and T4)in transgenic maize germplasms(S3002 and 349)containing the bivalent genes(insect resistance gene Cry1Ab13-1 and disease resistance gene NPR1)and their corresponding wild type.Results indicated that the target genes Cry1Ab13-1 and NPR1 were successfully transferred into both germplasms through tested generations;q-PCR confirmed the expression of Cry1Ab13-1 and NPR1 genes in roots,stems,and leaves of tested maize plants.In addition,S3002 and 349 bivalent gene-transformed lines exhibited resistance to large leaf spots and corn borer in the field evaluation compared to the wild type.Our study confirmed that Cry1Ab13-1 and NPR1 bivalent genes enhanced the resistance against maize borer and large leaf spot disease and can stably inherit.These findings could be exploited for improving other cultivated maize varieties.
基金the National Natural Science Foundation of China(32201787,32201793)the Innovation Special Program of Henan Agricultural University for Science and Technology(30501044)the Special Support Fund for High-Level Talents of Henan Agricultural University(30501302).
文摘Maize(Zea mays L.)is an indispensable crop worldwide for food,feed,and bioenergy production.Fusarium verticillioides(F.verticillioides)is a widely distributed phytopathogen and incites multiple destructive diseases in maize:seedling blight,stalk rot,ear rot,and seed rot.As a soil-,seed-,and airborne pathogen,F.verticillioides can survive in soil or plant residue and systemically infect maize via roots,contaminated seed,silks,or external wounds,posing a severe threat to maize production and quality.Infection triggers complex immune responses:induction of defense-response genes,changes in reactive oxygen species,plant hormone levels and oxylipins,and alterations in secondary metabolites such as flavonoids,phenylpropanoids,phenolic compounds,and benzoxazinoid defense compounds.Breeding resistant maize cultivars is the preferred approach to reducing F.verticillioides infection and mycotoxin contamination.Reliable phenotyping systems are prerequisites for elucidating the genetic structure and molecular mechanism of maize resistance to F.verticillioides.Although many F.verticillioides resistance genes have been identified by genome-wide association study,linkage analysis,bulkedsegregant analysis,and various omics technologies,few have been functionally validated and applied in molecular breeding.This review summarizes research progress on the infection cycle of F.verticillioides in maize,phenotyping evaluation systems for F.verticillioides resistance,quantitative trait loci and genes associated with F.verticillioides resistance,and molecular mechanisms underlying maize defense against F.verticillioides,and discusses potential avenues for molecular design breeding to improve maize resistance to F.verticillioides.
基金supported by National Natural Science Foundation of China(30901021)863the Key Programs for Science and Technology Development of Hubei Province
文摘Over the past years, infectious disease has caused enormous economic loss in pig industry. Among the pathogens, gram negative bacteria not only cause inflammation, but also cause different diseases and make the pigs more susceptible to virus infection. Vaccination, medication and elimination of sick pigs are major strategies of controlling disease. Genetic methods, such as selection of disease resistance in the pig, have not been widely used. Recently, the completion of the porcine whole genome sequencing has provided powerful tools to identify the genome regions that harboring genes controlling disease or immunity. Immunogenornics, which combines DNA variations, transcriptorne, immune response, and QTL mapping data to illustrate the interactions between pathogen and host immune system, will be an effective genomics tool for identification of disease resistance genes in pigs. These genes will be potential targets for disease resistance in breeding programs. This paper reviewed the progress of disease resistance study in the pig focusing on Gram-negative bacilli. Major porcine Gram-negative bacilli and diseases, suggested candidate genes/pathways against porcine Gram-negative bacilli, and distributions of QTLs for immune capacity on pig chromosomes were summarized. Some tools for immunogenomics research were described. We conclude that integration of sequencing, whole genome associations, functional genomics studies, and immune response information is necessary to illustrate molecular mechanisms and key genes in disease resistance.
基金Supported by China Spark Program(2011GA780008)~~
文摘Jiyou 360, a new hybrid rice combination, was developed by the Guangdong Jindao Seed Co., Ltd. and Rice Research Institute of Guangdong Academy of Agricultural Sciences with restorers Guanghui 360 and Jifeng A as the parents. This combination is highly resistant to blast, and it was approved as a new variety by the Guangdong Provincial Crop Variety Approval Committee in February 2016, with approval number of YSD 2016015, Jiyou 360 is suitable for planting in Guangdong Province as early and late rice.
文摘This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and countermeasures for solving.
文摘Rapeseed is an important oil crop with high economic value.It can be used not only as edible oil and livestock feed,but also in medicine,industry and tourism.Sclerotium sclerotiorum is a necrotrophic fungal pathogen that harms the yield and quality of rape.This article mainly summarizes the research status of S.sclerotiorum from three aspects:the biological characteristics,infection mode,process and disease resistance breeding of S.sclerotiorum,and summarizes the future research directions of antibacterial sclerotium on rape,to provide reference for future research on sclerotinia.
基金Supported by Project of Jilin Department of Education(2013076)
文摘Eggplant phomopsis rot was summarized from the aspects of distribution and damage, pathogen identification and pathogenicity differentiation, and disease-resistant breeding. Furthermore, some existing problems and research directions in future was also discussed.
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.
文摘In this paper a general introduction is given to research advances in genetics improvement and breeding of Chinese aspen (Populus davidiana Dode) in China. This introduction includes natural distribution and collection, conservation, gene diversity, provenance trial, crossing breeding, vegetative propagation and disease resistant etc. Based on the current situation of forest tree breeding in China, some strategic suggestions concerning the future development of Chinese aspen genetics improvement in China are presented, taking into consideration the existing domestic demands of forestry production and international trends in forest tree breeding.
基金supported by the National Natural Science Foundation of China (31625023 and 32001959)the Natural Science Foundation of Jiangsu Province (BK20200286 and BK20170616)the Open Fund of Jiangsu Key Laboratory for the Research and Utilization of Plant Resources(JSPKLB202025)。
文摘The development of durable and broad-spectrum resistance is an economical and eco-friendly approach to control crop diseases for sustainable agricultural production. Emerging knowledge of the molecular basis of pathogenesis and plant–pathogen interactions has contributed to the development of novel pathogen-informed breeding strategies beyond the limits imposed by conventional breeding. Here,we review the current status of pathogen-assisted resistance-related gene cloning. We also describe how pathogen effector proteins can be used to identify resistance resources and to inform cultivar deployment. Finally, we summarize the main approaches for pathogen-directed plant improvement,including transgenesis and genome editing. Thus, we describe the emerging role of pathogen-related studies in the breeding of disease-resistant varieties, and propose innovative pathogen-informed strategies for future applications.
基金supported by the Japan International Cooperation Agency as part of the Wonder Rice Initiative for Food Security and Health (WISH) Projectin part by the Canon Foundation and the SATREPS project entitled ‘Improvement in Productivity and Yield Stability of Rice under Kenya’s Biotic and Abiotic Stress Conditions Through Tailor-made Breeding and Development of Cultivation Methods’.
文摘The quantitative resistance gene pi21 from Sensho was introgressed to an indica breeding line IR63307-4B-13-2,a pyramiding line IRBB4/5/13/21,and a tropical japonica line Kinandang Patong by marker-assisted backcrossing.A total of 192 improved lines at the BC4F3 and BC4F4 generations were developed and confirmed to have the gene introgression via genotyping using a pi21-specific InDel marker.Thirteen randomly selected improved lines,representing all the three genetic backgrounds,demonstrated resistance against leaf blast composites in the field and a broader spectrum resistance against individual isolates compared to the recurrent parents in the glasshouse.Specifically,the tested lines exhibited pi21-acquired resistance against 11 leaf blast isolates that elicited susceptible reactions from the recurrent parents.All the tested lines maintained a comparative heading date,and similar or improved panicle length,number of primary branches per panicle and number of total grains per panicle relative to the recurrent parents.The physical grain characteristics of the recurrent parents were also maintained in the 13 lines tested,although variability in the amylose content and chalkiness degree was observed.The successful marker-assisted introgression of pi21 in diverse genetic backgrounds and the resulting broader spectrum resistance of improved lines against leaf blast indicate the potential of pi21 for deployment in cultivars grown across other rice growing regions in Asia.