This study was conducted to analyze the phenotypic and genotypic similarity or diversity of rice （Oryza sativa L.） landraces in household and hypothermic genebank conservations in Hunan Province and identify the gen...This study was conducted to analyze the phenotypic and genotypic similarity or diversity of rice （Oryza sativa L.） landraces in household and hypothermic genebank conservations in Hunan Province and identify the genetic distance between the rice landraces with the same or similar names. A total of 92 accessions of rice landraces were divided into seven groups according to their local names, but the morphological traits showed large variations even within the same group as well as between household and genebank conservations. The SSR marker analysis showed that, in all the groups except Group E, the allelic variations within each subgroup of the household conservation were less than those of the genebank conservation, indicating the household-conserved rice landraces’ many-generation purifcation from natural and artifcial selections in the process of their cultivation year after year; and the similarity coeffcient among the household rice landraces was the highest except for Groups C and E. Thus, the study suggested that the same-name or similar-name rice resources retained by farmers would be valuable for collection and evaluation.展开更多
Speciation research has seen a renewed interest in ecological speciation, which emphasises divergent ecological se- lection leading to the evolution of reproductive isolation. Selection from divergent ecologies means ...Speciation research has seen a renewed interest in ecological speciation, which emphasises divergent ecological se- lection leading to the evolution of reproductive isolation. Selection from divergent ecologies means that phenotypic plasticity can play an important role in ecological speciation. Phenotypic plasticity involves the induction of phenotypes over the lifetime of an organism and emerging evidence suggests that epigenetic marks such as cytosine and protein （histone） modifications might regu- late such environmental induction. Epigenetic marks play a wide role in a variety of processes including development, sex dif- ferentiation and allocation, sexual conflict, regulation of transposable elements and phenotypic plasticity. Here we describe recent studies that investigate epigenetic mechanisms in a variety of contexts. There is mounting evidence for environmentally induced epigenetic variation and for the stable inheritance of epigenetic marks between generations. Thus, epigenetically-based pheno- typic plasticity may play a role in adaptation and ecological speciation. However, there is less evidence for the inheritance of in- duced epigenetic variation across multiple generations in animals. Currently few studies of ecological speciation incorporate the potential for the involvement of epigenetically-based induction of phenotypes, and we argue that this is an important omission [Current Zoology 59 （5）： 686-696, 2013 ].展开更多
基金Supported by Protection Fund for Species Resources of Ministry of Agriculture(1120162130135252036)the Third Chinese Crop Germplasm Resources Census and CollectionSpecial Fund for National Modern Agro-Industrial Technology System Construction(nycytx-001)~~
文摘This study was conducted to analyze the phenotypic and genotypic similarity or diversity of rice （Oryza sativa L.） landraces in household and hypothermic genebank conservations in Hunan Province and identify the genetic distance between the rice landraces with the same or similar names. A total of 92 accessions of rice landraces were divided into seven groups according to their local names, but the morphological traits showed large variations even within the same group as well as between household and genebank conservations. The SSR marker analysis showed that, in all the groups except Group E, the allelic variations within each subgroup of the household conservation were less than those of the genebank conservation, indicating the household-conserved rice landraces’ many-generation purifcation from natural and artifcial selections in the process of their cultivation year after year; and the similarity coeffcient among the household rice landraces was the highest except for Groups C and E. Thus, the study suggested that the same-name or similar-name rice resources retained by farmers would be valuable for collection and evaluation.
文摘Speciation research has seen a renewed interest in ecological speciation, which emphasises divergent ecological se- lection leading to the evolution of reproductive isolation. Selection from divergent ecologies means that phenotypic plasticity can play an important role in ecological speciation. Phenotypic plasticity involves the induction of phenotypes over the lifetime of an organism and emerging evidence suggests that epigenetic marks such as cytosine and protein （histone） modifications might regu- late such environmental induction. Epigenetic marks play a wide role in a variety of processes including development, sex dif- ferentiation and allocation, sexual conflict, regulation of transposable elements and phenotypic plasticity. Here we describe recent studies that investigate epigenetic mechanisms in a variety of contexts. There is mounting evidence for environmentally induced epigenetic variation and for the stable inheritance of epigenetic marks between generations. Thus, epigenetically-based pheno- typic plasticity may play a role in adaptation and ecological speciation. However, there is less evidence for the inheritance of in- duced epigenetic variation across multiple generations in animals. Currently few studies of ecological speciation incorporate the potential for the involvement of epigenetically-based induction of phenotypes, and we argue that this is an important omission [Current Zoology 59 （5）： 686-696, 2013 ].
