This paper traces the origins and achievements of the R^seau Ouest et Centre Africain du Riz--ROCARIZ （West and Central Africa Rice Research and Development Network）. The ROCARIZ institutional arrangement showed tha...This paper traces the origins and achievements of the R^seau Ouest et Centre Africain du Riz--ROCARIZ （West and Central Africa Rice Research and Development Network）. The ROCARIZ institutional arrangement showed that rice science is approached from multi-stakeholder perspectives that place end users and entrepreneurs at the center of research for development, and collaboration among rice-based stakeholders can be enhanced and sustained. The ROCARIZ used competitive research grants through multi-stakeholder task forces to generate, adapt, and facilitate the adoption of rice-based technologies and approaches by resource poor households. The grants contributed to： （1） farmer adoption of high yielding and multiple stress resilient lowland NERICAs （New Rices for Africa） （NERICA-L）; （2） producer access to credit and services resulting in increased marketing of quality seed rice, paddy, and grain rice by farmer entrepreneurs and poor rural households; （3） improved skills of stakeholders on the use of impact assessment tools to demonstrate adoption of rice-based technologies; （4） enhanced skills of rice breeders in molecular assisted marker selection to shorten the varietal development process; and （S） experiential learning and sharing to improve access to information and knowledge.展开更多
Hybrid rice technology in China was developed in three stages. From the 1950s onwards, hybrid rice researchers, as typified by Yuan Longping, sought out a feasible approach to utilizing rice heterosis, and developed t...Hybrid rice technology in China was developed in three stages. From the 1950s onwards, hybrid rice researchers, as typified by Yuan Longping, sought out a feasible approach to utilizing rice heterosis, and developed the three-line indica hybrid rice. Led by the government, the hybrid rice technology R&D teams adopted the research mode of "large-scale cooperation"(大协作), and accomplished technical innovations in the three-line system, selective breeding, and production of hybrid seeds. In the ensuing decade, Yuan Longping and others discovered the photo-thermo sensitive genic male sterility(PTGMS) of rice and developed PTGMS lines, turning highly advantageous two-line rice breeding from scientific vision into reality. Over the next twenty-five years, China’s super-rice breeding program integrated the conventional, three-line, and two-line breeding methods with modern molecular biotechnology methods. For nearly half a century, China made outstanding attainments in acquiring quality strains that yielded enormous economic and social benefits. Throughout this process, factors such as urgent social demand for increased grain production and scientific research cooperation provided significant impetus.展开更多
Conventional rice breeding has long focused on exploiting the DNA sequence diversity.However,epigenetic diversity,reflected particularly in DNA methylation,can also contribute to phenotypic variation and should not be...Conventional rice breeding has long focused on exploiting the DNA sequence diversity.However,epigenetic diversity,reflected particularly in DNA methylation,can also contribute to phenotypic variation and should not be overlooked in rice breeding.In this study,20 parental lines of indica rice,which are widely used in hybrid rice breeding in China,were analyzed to investigate variations of DNA methylation and its inheritance.The results revealed a wide diversity in DNA methylation among these breeding lines.A positive correlation was seen between DNA methylation and genetic diversity.Furthermore,some of the methylated DNA was inherited in the subsequent generation,regardless of whether they were produced by selfing or hybrid-crossing.This study provides insight into the methylation patterns in rice,and suggests the importance of epigenetic diversity in rice breeding.展开更多
文摘This paper traces the origins and achievements of the R^seau Ouest et Centre Africain du Riz--ROCARIZ （West and Central Africa Rice Research and Development Network）. The ROCARIZ institutional arrangement showed that rice science is approached from multi-stakeholder perspectives that place end users and entrepreneurs at the center of research for development, and collaboration among rice-based stakeholders can be enhanced and sustained. The ROCARIZ used competitive research grants through multi-stakeholder task forces to generate, adapt, and facilitate the adoption of rice-based technologies and approaches by resource poor households. The grants contributed to： （1） farmer adoption of high yielding and multiple stress resilient lowland NERICAs （New Rices for Africa） （NERICA-L）; （2） producer access to credit and services resulting in increased marketing of quality seed rice, paddy, and grain rice by farmer entrepreneurs and poor rural households; （3） improved skills of stakeholders on the use of impact assessment tools to demonstrate adoption of rice-based technologies; （4） enhanced skills of rice breeders in molecular assisted marker selection to shorten the varietal development process; and （S） experiential learning and sharing to improve access to information and knowledge.
文摘Hybrid rice technology in China was developed in three stages. From the 1950s onwards, hybrid rice researchers, as typified by Yuan Longping, sought out a feasible approach to utilizing rice heterosis, and developed the three-line indica hybrid rice. Led by the government, the hybrid rice technology R&D teams adopted the research mode of "large-scale cooperation"(大协作), and accomplished technical innovations in the three-line system, selective breeding, and production of hybrid seeds. In the ensuing decade, Yuan Longping and others discovered the photo-thermo sensitive genic male sterility(PTGMS) of rice and developed PTGMS lines, turning highly advantageous two-line rice breeding from scientific vision into reality. Over the next twenty-five years, China’s super-rice breeding program integrated the conventional, three-line, and two-line breeding methods with modern molecular biotechnology methods. For nearly half a century, China made outstanding attainments in acquiring quality strains that yielded enormous economic and social benefits. Throughout this process, factors such as urgent social demand for increased grain production and scientific research cooperation provided significant impetus.
基金supported by the National Natural Science Foundation of China(31071379)the Post-Doctoral Foundation of China(20090450616)a grant from"Yellow Crane"Special Talent Program of Wuhan
文摘Conventional rice breeding has long focused on exploiting the DNA sequence diversity.However,epigenetic diversity,reflected particularly in DNA methylation,can also contribute to phenotypic variation and should not be overlooked in rice breeding.In this study,20 parental lines of indica rice,which are widely used in hybrid rice breeding in China,were analyzed to investigate variations of DNA methylation and its inheritance.The results revealed a wide diversity in DNA methylation among these breeding lines.A positive correlation was seen between DNA methylation and genetic diversity.Furthermore,some of the methylated DNA was inherited in the subsequent generation,regardless of whether they were produced by selfing or hybrid-crossing.This study provides insight into the methylation patterns in rice,and suggests the importance of epigenetic diversity in rice breeding.
