Studies On Genetic Diversity Of Luffa Germplasm Resources

Luffa is an important horticultural plant with abundant nutritious ingredient and that is of greatbenefit to human health. The study on the genetic diversity of Luffa can benefit the conservation,classification, identification, genetic enhancement and effective utilization of the Luffa germplasmresources. Molecular marker, which can detect the genetic diversity at DNA level, is a powerful toolfor genetic diversity study. RAPD markers have been popularized for their simplicity, rapidity andnon-specialty among different genera. In this study, the genetic diversity in 26 Luffa accessions fromdifferent countries or regions were assessed via morphological descriptors and RAPD markers, and thegenetic relationship among the accessions was revealed by hierarchical cluster analysis, principalcomponents analysis at various level.The main results were as follows:In order to assess genetic diversity of 26 Luffa Germplasm, a total of 44 morphologicaldescriptors (18 quantitative and 26 qualitative) were measured. The UPGMA coefficient of variationwas 32.75ï¼…. They ranged from 5.27ï¼…in leaf shape index to 31.57ï¼…in UPGMA fruit weight based onthe 18 quantitative descriptors and from 20.28ï¼…in leaf shape to 107ï¼…in fruit ribs based on the 26qualitative descriptors.The UPGMA Shannon's Information index among the accessions was 1.27 based on the data of44 morphological descriptors. They varied from 1 in leaf shape index to 1.91 in peduncle length orseed height based on the 18 quantitative descriptors and from 0.49 in seed surface to 1.87 in number ofnodes under first male flower based on the 26 qualitative descriptors.The 26 Luffa germplasm were clustered into 2 groups based on the morphological data. The firstgroup includes all L. cylindrica Roem.type, and the second group includes all L. acutangulaRoxb.type.The results of principal components analysis showed accumulative variance contribution ofthe first three principal components was 55.87ï¼…. The variance contribution of the first principalcomponent was 35.33ï¼…. The results of hierarchical cluster analysis were in accord with principalcomponents analysis.A total of 200 10-mer random primers were used in this study. 16 screened primers produced 145scorable and repeatable RAPD bands, of which 125 bands (86.21ï¼…) were polymorphic across 26 Luffaaccessions. The Shannon's Information index of RAPD loci was 0.325. 26 Luffa germplasm wereclustered into 2 groups based on the RAPD data by the method of hierarchical cluster analysis. Theaccumulative variance contribution of the first three principal components was 89.03ï¼…. The firstprincipal component encompassed 76.61ï¼…of the total variation.All the results above confirmed that the level of polymorphism was medium in the 26 Luffagermplasm.The genetic distance between the 5 L. acutangula Roxb. germplasm and the others waslarger than that among the 21 L. cylindrica Roem. germplasm..