Diversity Of Rosa Odorata Var. Gigantea In Liangwangshan Mountains,Yunnan

Rosa odorata var.gigantea is a member of Sect.Chinenses,Rosa L.,Rosaceae,which is the one of original species of Rosa odorata and one of the important indirect parents of Old Chinese rose cultivars and modern rose.However,in recent years,with the emergence of habitat loss,artificial mining and other problems,the number of Rosa odorata var.gigantea has decreased,and the genetic diversity may gradually lose.Therefore,it is urgent to carry out field investigation and conservation research on it.In the study,phenotypic and pollen diversity of three Rosa odorata var.gigantea populations containing 240plants was measured and analyzed in Liangwangshan Mountains,Chengjiang City,Yunnan province.The main conclusions of the study are as follows:1.Field investigation found extensive variation among Rosa odorata var.gigantea plants,mainly reflected in habit,number of scolus,petal shape,style and stigma color,number of glandular hairs,number and shape of leaflets,fruit shape and so on.2.Phenotypic diversity of Rosa odorata var.gigantea abundant was both within and between populations,and the total mean value of phenotypic differentiation coefficient(V_ST)was only 9.05%.In a relatively short distance,intra-population variation was the main source of variability.The average variation coefficient of phenotypic traits in the population was 15.52%,and the stability of reproductive and nutritive organs may not be significantly different.3.Most of non-metrical phenotypic traits had complex genetic relationships with low or even no correlation,such as growth,number of glandular hairs and fruit set number.Most of metrical phenotypic traits had significant or extremely significant correlations,such as petal size,leaflet size,and stipule size.but the correlation between vegetative growth and reproductive growth was not strong.4.Principal component analysis showed that the intraspecies differences of Rosa odorata var.gigantea were mainly reflected in the shape and size of leaf and stipule,the shape and size of petal and sepal,the number of seeds per fruit and fruit shape,which could be used as important morphological indicators for the evaluation and conservation of Rosa odorata var.gigantea resources.5.The pollen of Rosa odorata var.gigantea belongs to N₃P₄C₅ type,most of which are perprolate,and the pollen exine has long strip ornamentation.The variation coefficient of pollen traits ranged from4.41%-19.44%,with an average variation coefficient of 8.32%.There were some differences in pollen size,shape and pollen exine,especially rich variations in striae width and striae distance among populations,which indicated the rich genetic diversity of Rosa odorata var.gigantea.The study provides a theoretical basis for the protection,utilization and classification of the germplasm resources of Rosa odorata var.gigantea.