Studies on genetic diversity in chrysanthemum (Chrysanthemum morifolium Ramat.) through hybridization, cytological and molecular approaches for commercial traits
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
The present investigations entitled “Studies on genetic diversity in chrysanthemum (Chrysanthemum morifolium Ramat.) through hybridization, cytological and molecular approaches for commercial traits” were undertaken at Department of Floriculture and Landscaping, Department of Plant Breeding and Genetics and Fruit Molecular Biotechnology Lab in School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, during 2016-19. The study consisted of genetic diversity analysis of diverse genotypes of chrysanthemum through cytological, molecular studies and hybridization for commercial traits. Thirty chrysanthemum genotypes were selected from chrysanthemum germplasm maintained at PAU, Ludhiana for cytological studies. Young flower buds were used for preparation of slides and a range of ploidy level 2n=52-116 recorded among all selected chrysanthemum cultivars. In molecular characterization SSR markers were used to study genetic diversity of thirty chrysanthemum genotypes. Total 17 SSR‟s were selected and among these 15 markers exhibited polymorphism and remaining two were monomorphic. Fifteen polymorphic markers demonstrated relatively high level of polymorphism as out of total 53 alleles produced, 47 were polymorphic showing 92.22 % polymorphism. Genotypes were clustered into two main clusters based on the variability of 15 polymorphic SSR markers. In hybridization twenty-one crosses were made between cultivars belonging to early and main season group. Among twenty-one crosses seed set was recorded in sixteen crosses and germination per cent was observed in fourteen crosses only. Maximum number of seeds per flower head were found in cross Ratlam Selection x Reagan Emperor (11.00), highest seed germination percentage (40.00 %) was recorded in cross between Basanti x Reagan Emperor and seedling vigour found highest (60.00) in cross between Basanti x Reagan Emperor. Hybrids developed from inter crossing of chrysanthemum genotypes were evaluated for various morphological characters and showed variation with respect to flower colour and flower type can be used for different purposes like for pot culture, exhibition purpose and for loose flower production etc. From the effective positive response in terms of various investigations under study, it can be concluded that chromosomal and molecular study helped to estimate genetic diversity which is the most essential pre-requisite as it plays an important role in developing new and novel desired forms through breeding and selection. Polyploidy found could be further helpful for breeding programmes and new cultivars could be developed by addition or deletion of chromosomes in cultivars with known ploidy level. Hybridization helps in development of segregating population having different range of flower colour and height and can be used for different floricultural purposes.