Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentant...Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera （G. Don） Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi （Sweet） Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding ＆ Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.展开更多
Evergreen azaleas are among the most important ornamental shrubs in China.Today,there are probably over 300 cultivars preserved in different nurseries,but with little information available on the cultivar itself or re...Evergreen azaleas are among the most important ornamental shrubs in China.Today,there are probably over 300 cultivars preserved in different nurseries,but with little information available on the cultivar itself or relationships between cultivars.Amplified fragment length polymorphism(AFLP) markers were employed to determine the genetic relationships between evergreen azalea cultivars in China.One hundred and thirty genotypes collected from gardens and nurseries,including cultivars classified in the groups East,West,Hairy,and Summer,unknown cultivars,and close species,were analyzed using three primer pairs.A total of 408 polymorphic fragments were generated by AFLP reactions with an average of 136 fragments per primer pair.The average values of expected heterozygosity and Shannon's information index were 0.3395 and 0.5153,respectively.Genetic similarities were generated based on Dice coefficients,used to construct a neighbor joining tree,and bootstrapped for 100 replicates in Treecon V1.3b.Principal coordinate analysis(PCO) was performed based on Dice distances using NTSYS-pc software.The AFLP technique was useful for analyzing genetic diversity in evergreen azaleas.Cluster analysis revealed that cultivars in the West and Summer groups were quite distinct from other groups in the four-group classification system and that the East and Hairy groups should be redefined.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.30370106)
文摘Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera （G. Don） Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi （Sweet） Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding ＆ Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.
基金Project(No.2012C12909-7) supported by the Science and Technology Major Project of Zhejiang Province,China
文摘Evergreen azaleas are among the most important ornamental shrubs in China.Today,there are probably over 300 cultivars preserved in different nurseries,but with little information available on the cultivar itself or relationships between cultivars.Amplified fragment length polymorphism(AFLP) markers were employed to determine the genetic relationships between evergreen azalea cultivars in China.One hundred and thirty genotypes collected from gardens and nurseries,including cultivars classified in the groups East,West,Hairy,and Summer,unknown cultivars,and close species,were analyzed using three primer pairs.A total of 408 polymorphic fragments were generated by AFLP reactions with an average of 136 fragments per primer pair.The average values of expected heterozygosity and Shannon's information index were 0.3395 and 0.5153,respectively.Genetic similarities were generated based on Dice coefficients,used to construct a neighbor joining tree,and bootstrapped for 100 replicates in Treecon V1.3b.Principal coordinate analysis(PCO) was performed based on Dice distances using NTSYS-pc software.The AFLP technique was useful for analyzing genetic diversity in evergreen azaleas.Cluster analysis revealed that cultivars in the West and Summer groups were quite distinct from other groups in the four-group classification system and that the East and Hairy groups should be redefined.
