From 2003 to 2005, in pot and field experiments, rice response to salinity stress of 15 rice varieties was studied at germination and young seedling stages using salt affected soils collected from rice production area...From 2003 to 2005, in pot and field experiments, rice response to salinity stress of 15 rice varieties was studied at germination and young seedling stages using salt affected soils collected from rice production areas in the Office du Niger zone of Mali. The rice varieties were composed of 10 rice genotypes from the breeding program of Mali and five from West African Rice Development Association （WARDA） program （Saint Louis, Senegal）. Soil samples were collected from the visually affected soils which were characterized by the appearance of white or black efflorescence on the soil surface. In pot experiments, the genotypes were allowed to germinate in both affected soil types （white efflorescence and black efflorescence） and salt effects on plant seedling growth were observed. Results showed that all varieties were significantly sensitive to salinity stress based on germination, young seedling shoot and root dry weights. Among the rice varieties, the most salt tolerant variety was BG90-2 （a high yielding genotype from the Institut d＇Economie Rurale （IER） breeding program） while the most sensitive variety was Telimani （also from the breeding program of IER）. All other varieties were intermediary between these two genotypes. A three year field experiment conducted in a highly affected area near Niono confirmed the results of the pot experiment. The relatively salt tolerant genotypes were found in both Malian （BG90-2, Kogoni91-1, SK51-5-2） and WARDA （Was30-11-1-1-4-6-1B） rice breeding programs.展开更多
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
文摘From 2003 to 2005, in pot and field experiments, rice response to salinity stress of 15 rice varieties was studied at germination and young seedling stages using salt affected soils collected from rice production areas in the Office du Niger zone of Mali. The rice varieties were composed of 10 rice genotypes from the breeding program of Mali and five from West African Rice Development Association （WARDA） program （Saint Louis, Senegal）. Soil samples were collected from the visually affected soils which were characterized by the appearance of white or black efflorescence on the soil surface. In pot experiments, the genotypes were allowed to germinate in both affected soil types （white efflorescence and black efflorescence） and salt effects on plant seedling growth were observed. Results showed that all varieties were significantly sensitive to salinity stress based on germination, young seedling shoot and root dry weights. Among the rice varieties, the most salt tolerant variety was BG90-2 （a high yielding genotype from the Institut d＇Economie Rurale （IER） breeding program） while the most sensitive variety was Telimani （also from the breeding program of IER）. All other varieties were intermediary between these two genotypes. A three year field experiment conducted in a highly affected area near Niono confirmed the results of the pot experiment. The relatively salt tolerant genotypes were found in both Malian （BG90-2, Kogoni91-1, SK51-5-2） and WARDA （Was30-11-1-1-4-6-1B） rice breeding programs.
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.
