: The genetic diversity and genetic structure of a population of isolates of Sclerotinia sclerotiorum (Lib.) de Bary from different regions and host plants were investigated using the random amplified polymorphic DNA ...: The genetic diversity and genetic structure of a population of isolates of Sclerotinia sclerotiorum (Lib.) de Bary from different regions and host plants were investigated using the random amplified polymorphic DNA (RAPD) method with 20 random decamer primer pairs in order to provide some information on the phylogenetic taxa and breeding for resistance to sclerotinia stem rot. A minimum of three and a maximum of 15 unambiguously amplified bands were generated, furnishing a total of 170 bands ranging in size from 100 to 3 200 bp, corresponding to an average of 8.5 bands per primer pair. One hundred and four of these 170 bands (61.2%) were polymorphic, the percentage of polymorphic bands for each primer pair ranging from 0.0% to 86.7%. The genetic relationships among the isolates, based on the results of RAPD analysis, were examined. The genetic similarity of all selected isolates was quite high. At the species level, the genetic diversity estimated by Nei's gene diversity (h) was 0.197 and Shannon's index of diversity (I) was 0.300. The unweighted pair-group mean analysis (UPGMA) cluster analysis showed that most isolates from the same regions were grouped in the same cluster or a close cluster. The population of isolates from Hefei (Anhui Province, China) was more uniform and relatively distant to other populations. The Canadian population collected from carrot (Daucus carota var. sativa DC.) was relatively close to the Polish population collected from oilseed rape (Brassica napus L.) plants. There was no relationship between isolates from the same host plants. An analysis of molecular variance (AMOVA) revealed that the percentage of variance attributable to variation among and within populations was 50.62% and 49.38%, respectively. When accessions from China, Europe, and Canada were treated as three separate groups, the variance components among groups, among populations within groups, and within populations were ?0.96%, 51.48%, and 49.47%, respectively. The genetic differentiations among and within population展开更多
Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent year...Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent years. The objective of this research was to determine the effectiveness of two measurements of disease rating in predicting the field reaction of cultivars to sclerotinia stem rot. One hundred and ten cultivars or lines of oilseed rape were repeatedly evaluated the disease severity index (DSI) and lesion length for their resistance to nine isolates of S. sclerotiorum in two field stations. There were greatly significant differences between two stations, among isolates, among population of cultivars for the disease severity index and lesion length, and also significant station×isolate interaction for lesion length and population×isolate interactions for DSI and lesion length, but interactions of station×isolate for DSI were not significant. Cultivars such as Pomorzanin and Lisek consistently had the lowest disease severity ratings in the field tests. However, most of cultivars were susceptible to sclerotinia stem rot in the field test. A positive correlation between the mean DSI and lesion length was found for both isolates (Sc23 and B1). The correlations ranged from 0.23 to 0.83 at various plots, with nine of the twelve correlations significant. The correlations for disease caused by different fungal isolates were statistically significant difference. These correlations ranged from -0.44 to 0.90, with nine of the thirty-two correlations significant. It indicated that resistance to some isolates was significantly correlated and selection of some varieties for resistance to one isolate appeared to improve resistance to other isolates.展开更多
基金Basic Research and Development Plan of China，国家科技攻关项目，the Sino-Polish Scientific and Technological Cooperation Project for 2004-2006，中国科学院资助项目
文摘: The genetic diversity and genetic structure of a population of isolates of Sclerotinia sclerotiorum (Lib.) de Bary from different regions and host plants were investigated using the random amplified polymorphic DNA (RAPD) method with 20 random decamer primer pairs in order to provide some information on the phylogenetic taxa and breeding for resistance to sclerotinia stem rot. A minimum of three and a maximum of 15 unambiguously amplified bands were generated, furnishing a total of 170 bands ranging in size from 100 to 3 200 bp, corresponding to an average of 8.5 bands per primer pair. One hundred and four of these 170 bands (61.2%) were polymorphic, the percentage of polymorphic bands for each primer pair ranging from 0.0% to 86.7%. The genetic relationships among the isolates, based on the results of RAPD analysis, were examined. The genetic similarity of all selected isolates was quite high. At the species level, the genetic diversity estimated by Nei's gene diversity (h) was 0.197 and Shannon's index of diversity (I) was 0.300. The unweighted pair-group mean analysis (UPGMA) cluster analysis showed that most isolates from the same regions were grouped in the same cluster or a close cluster. The population of isolates from Hefei (Anhui Province, China) was more uniform and relatively distant to other populations. The Canadian population collected from carrot (Daucus carota var. sativa DC.) was relatively close to the Polish population collected from oilseed rape (Brassica napus L.) plants. There was no relationship between isolates from the same host plants. An analysis of molecular variance (AMOVA) revealed that the percentage of variance attributable to variation among and within populations was 50.62% and 49.38%, respectively. When accessions from China, Europe, and Canada were treated as three separate groups, the variance components among groups, among populations within groups, and within populations were ?0.96%, 51.48%, and 49.47%, respectively. The genetic differentiations among and within population
基金The research was supported by the State Key Basic Research and Development Plan of China(2004CB 117200,2002CB111300)the Hi-Tech Research and De-velopment Program of China(2004AA21111)+1 种基金the China Scholarship Council,the Sino-Polish Scientific and Technological Cooperation 2004 2006(3 1-23B)the National Natural Science Foundation of China(30000107).
文摘Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent years. The objective of this research was to determine the effectiveness of two measurements of disease rating in predicting the field reaction of cultivars to sclerotinia stem rot. One hundred and ten cultivars or lines of oilseed rape were repeatedly evaluated the disease severity index (DSI) and lesion length for their resistance to nine isolates of S. sclerotiorum in two field stations. There were greatly significant differences between two stations, among isolates, among population of cultivars for the disease severity index and lesion length, and also significant station×isolate interaction for lesion length and population×isolate interactions for DSI and lesion length, but interactions of station×isolate for DSI were not significant. Cultivars such as Pomorzanin and Lisek consistently had the lowest disease severity ratings in the field tests. However, most of cultivars were susceptible to sclerotinia stem rot in the field test. A positive correlation between the mean DSI and lesion length was found for both isolates (Sc23 and B1). The correlations ranged from 0.23 to 0.83 at various plots, with nine of the twelve correlations significant. The correlations for disease caused by different fungal isolates were statistically significant difference. These correlations ranged from -0.44 to 0.90, with nine of the thirty-two correlations significant. It indicated that resistance to some isolates was significantly correlated and selection of some varieties for resistance to one isolate appeared to improve resistance to other isolates.
