‘Ogura’-based ‘CMS’ lines with different nuclear backgrounds of cabbage revealed substantial diversity at morphological and molecular levels

Abstract

A comprehensive study on characterization and genetic diversity analysis was carried out in 16 'Ogura'-based 'CMS' lines of cabbage using 14 agro-morphological traits and 29 SSR markers. Agro-morphological characterization depicted considerable variations for different horticultural traits studied. The genotype, ZHA-2, performed better for most of the economically important quantitative traits. Further, gross head weight (0.76), head length (0.60) and head width (0.83) revealed significant positive correlation with net head weight. Dendrogram based on 10 quantitative traits exhibited considerable diversity among different CMS lines and principle component analysis (PCA) indicated that net and gross head weight, and head length and width are the main components of divergence between 16 CMS lines of cabbage. In molecular study, a total of 58 alleles were amplified by 29 SSR primers, averaging to 2.0 alleles in each locus. High mean values of Shannon's Information index (0.62), expected (0.45) and observed (0.32) heterozygosity and polymorphic information content (0.35) depicted substantial polymorphism. Dendrogram based on Jaccard's similarity coefficient constructed two major groups and eight sub-groups, which revealed substantial diversity among different CMS lines. In overall, based on agro-morphological and molecular studies genotype RRMA, ZHA-2 and RCA were found most divergent. Hence, they have immense potential in future breeding programs for the high-yielding hybrid development in cabbage.

Doubled haploid based parental lines are most suitable in predicting heterosis using microsatellites and in development of highly heterotic F1hybrids inBrassica oleracea

“…Thus, the information pertaining to morphological and genetic diversity along with GCA could be useful in selecting desirable CMS lines as female parent for the development of cultivars with desirable traits. Similar types of findings have been reported by Dey et al [17] and Parkash et al [58] with respect to CMS lines in Brassica oleracea .…”

“…Further, we observed high allele frequency of overall 511 alleles through 87 genomic-SSR and EST-SSRs loci in 26 parental CMS and DH lines with average allelic frequency of 5.87 alleles per locus. It is quite high as compared to results reported by Parkash et al [58], who observed only 58 total alleles with an average of 2 alleles per locus by 29 polymorphic SSRs in CMS lines of Brassica oleracea, and El-Esawi et al [19], who reported 47 alleles with an average of 3.92 alleles per locus by 12 SSRs in Brassica oleracea genotypes. The quite high number of total alleles and high allelic frequency per locus revealed in the present investigation is quite possible as we used over all more numbers of genomic-SSR and EST-SSRs (total 350 microsatellite primers) distributed throughout the Brassica oleracea genome (n = 9, CC, 2n = 2x = 18), of which 87 loci depicted clear cut polymorphism.…”

“…The identification of heterotic pools and analyzing existing genetic variation in CMS lines is the preliminary requisite for efficient use of elite CMS lines in heterosis breeding. Study of genetic diversity at morphological and molecular level has been regarded as potential tool in identification of promising parental lines for developing heterotic hybrids in Brassica oleracea [17, 19, 58, 87]. Based upon PCA and HCA of 26 parental CMS lines and DH testers for 16 phenotypic traits, it was evident that all the parental lines had sufficient genetic variation.…”

Introgression of ‘Ogura’ cytoplasm in cabbage alters its nutritional quality and antioxidant activities

“…Presently, Ogura based CMS is commercially used for hybrid seed production in Brassica vegetables (Yamagishi, Bhat, 2014). At Indian Agricultural Research Institute Regional Station in Katrain, also had developed Ogura based CMS lines of cabbage by inter-specific hybridization and repeated back-crossing (Parkash et al, 2018). But, introgression of alien cytoplasm in Brassica vegetables showed poor agronomic performance (Hoser-Krause, 1989), abnormal style and reduced nectaries (Dey et al, 2011), leaf chlorosis (Ren, Cao, 1990) and poor female fertility (Chamola et al, 2013).…”

“…Heterosis breeding plays a critical role in genetic improvement of any crop relative to yield and quality traits . Therefore, an efficient, economic, reliable and stable method of hybrid seed production is needed for successful F 1 hybrid breeding in cabbage (Parkash et al, 2018). The selfincompatibility system is effective in hybrid breeding of Brassica vegetables (Kitashiba, Nasrallah, 2014).…”