Robinia pseudoacacia is an important afforesta-tion tree introduced to China in 1878.In the present study,we examined the genetic diversity among 687 strains rep-resenting four improved varieties and two secondary pro...Robinia pseudoacacia is an important afforesta-tion tree introduced to China in 1878.In the present study,we examined the genetic diversity among 687 strains rep-resenting four improved varieties and two secondary prov-enances,comprising 641 clones and 46 seedlings.Ninety-one simple sequence repeats(SSRs)were selected through segregation analysis and polymorphism characterization,and all sampled individuals were genotyped using well-characterized SSR markers.After excluding loci with non-neutral equilibrium,missing locus data and null alleles,we used 36 primer pairs to assess the genetic diversity of these germplasm resources,revealing vast genetic differentiation among the samples,with an average of 8.352 alleles per locus and a mean Shannon′s index of 1.302.At the popula-tion level,the partitioning of variability was assessed using analysis of molecular variance,which revealed 93%and 7%variation within and among collection sites,respectively.Four clusters were detected using structure analysis,indi-cating a degree of genetic differentiation among the six populations.Insights into the genetic diversity and structure of R.pseudoacacia provide a theoretical basis for the con-servation,breeding and sustainable development in China.展开更多
Differences in drought tolerance were studied among three strains of black locust(Robinia pseudoacacia L.) clones(one-year-old micropropagated K2,K3 clones and a common diploid clone CK) under simulated natural drough...Differences in drought tolerance were studied among three strains of black locust(Robinia pseudoacacia L.) clones(one-year-old micropropagated K2,K3 clones and a common diploid clone CK) under simulated natural drought conditions.The experiment was carried out as a randomized complete blocks design.The following physiological variables were examined,biomass and allocation,photosynthetic characteristics,i.e.net photosynthetic rate(Pn),transpiration rate(E),stomatal conductance(Gs),intercellular CO2 concentration(Ci),instantaneous water use efficiency(WUEI),and long-term water use efficiency(WUEL).Results showed that the K2 and K3 had greater biomass,with the K3 displaying favorable ratio of root biomass to shoot and leaf biomass.Net photosynthetic rate(Pn) declined along with Gs,Ci and the ratio intercellular/ambient(Ci/Ca),under increasing drought stress.The decline in photosynthesis was mainly due to stomatal limitation.The K2 and K3 showed higher WUE and Pn than the CK.There were significant differences of drought level on WUEL,and the WUEL of K2 and K3 was greater than that of CK.Evaluation based overall physiological characteristics indicates the K2 and K3 are more drought tolerant,which are well adapted to the drought-stricken area of Northwest China.展开更多
基金This work was supported by the Doctoral Scientific Research Starting Foundation of Henan University of Science and Technology(13480089)National Nature Science Foundation of China(31570677)+1 种基金the National Key R&D Program of China(2017YFD0600503)the National Forestry and Grassland Administration of Science and Technology Development Center Project(2016007).
文摘Robinia pseudoacacia is an important afforesta-tion tree introduced to China in 1878.In the present study,we examined the genetic diversity among 687 strains rep-resenting four improved varieties and two secondary prov-enances,comprising 641 clones and 46 seedlings.Ninety-one simple sequence repeats(SSRs)were selected through segregation analysis and polymorphism characterization,and all sampled individuals were genotyped using well-characterized SSR markers.After excluding loci with non-neutral equilibrium,missing locus data and null alleles,we used 36 primer pairs to assess the genetic diversity of these germplasm resources,revealing vast genetic differentiation among the samples,with an average of 8.352 alleles per locus and a mean Shannon′s index of 1.302.At the popula-tion level,the partitioning of variability was assessed using analysis of molecular variance,which revealed 93%and 7%variation within and among collection sites,respectively.Four clusters were detected using structure analysis,indi-cating a degree of genetic differentiation among the six populations.Insights into the genetic diversity and structure of R.pseudoacacia provide a theoretical basis for the con-servation,breeding and sustainable development in China.
文摘Differences in drought tolerance were studied among three strains of black locust(Robinia pseudoacacia L.) clones(one-year-old micropropagated K2,K3 clones and a common diploid clone CK) under simulated natural drought conditions.The experiment was carried out as a randomized complete blocks design.The following physiological variables were examined,biomass and allocation,photosynthetic characteristics,i.e.net photosynthetic rate(Pn),transpiration rate(E),stomatal conductance(Gs),intercellular CO2 concentration(Ci),instantaneous water use efficiency(WUEI),and long-term water use efficiency(WUEL).Results showed that the K2 and K3 had greater biomass,with the K3 displaying favorable ratio of root biomass to shoot and leaf biomass.Net photosynthetic rate(Pn) declined along with Gs,Ci and the ratio intercellular/ambient(Ci/Ca),under increasing drought stress.The decline in photosynthesis was mainly due to stomatal limitation.The K2 and K3 showed higher WUE and Pn than the CK.There were significant differences of drought level on WUEL,and the WUEL of K2 and K3 was greater than that of CK.Evaluation based overall physiological characteristics indicates the K2 and K3 are more drought tolerant,which are well adapted to the drought-stricken area of Northwest China.
