The genetic diversity and relationships of cauliflower (Brassica oleracea var. botrytis) inbred lines assessed by using SSR markers

Abstract

Inbred lines are important germplasm in cauliflower breeding programs. To understand the genetic diversity and relationships of cauliflower inbred lines, the use of simple sequence repeat (SSR) markers will be of great value for parental line selection and breeding strategy design. In this study, the genetic diversity and relationships of 165 cauliflower inbred lines primarily derived from southeast China were assessed using SSR markers. Forty-three SSR markers were polymorphic across these inbred lines and generated a total of 111 alleles. The mean values of the number of alleles (Na), effective number of alleles (Ne), Shannon’s Information index (I), and polymorphism information content (PIC) per locus were 2.581, 1.599, 0.517 and 0.316, respectively. Genetic distance values among all pairs of the inbred lines varied from 0 to 0.67 with an average of 0.30. On the basis of genetic distance data estimated with the SSR markers, the 165 cauliflower inbred lines were classified into four main clusters (from group Ⅰ to group Ⅳ) by cluster analysis and four subpopulations (from POP 1 to POP 4) by structure analysis. The classification patterns of most cauliflower inbred lines were not consistent with their curd maturity, curd solidity or geographic origins. These results based on estimates by the SSR markers, suggested the genetic diversity of the 165 cauliflower inbred lines was relatively narrow. Therefore, pyramiding the valuable genes among different types of the cauliflower inbred lines is important to increase the genetic diversity to obtain desirable hybridization combinations. The information generated in this report will be useful for assessing germplasm and breeding in cauliflower.

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

“…In the present study the PIC content of 87 polymorphic loci ranged from 0.24-0.80 (Table 6), which classified all the 87 loci (g-SSR and EST-SSRs) as slightly informative (1 primer cnu107), reasonably informative (12 primers) and highly informative markers (74 primers) as per PIC content (Table 6), suggesting their ability in genetic differentiation of CMS and DH lines of cauliflower under study. The mean PIC content of 0.63 in present investigation based on 87 g-SSR and EST-SSRs was higher than the mean PIC of 0.316 observed for 165 cauliflower inbred lines by Zhu et al [92] and 0.60 as recorded for 57 genotypes of Brassica oleracea comprising 51 cultivars of cauliflower by Zhao et al [93]. The higher PIC value for most of loci revealed wide genetic diversity in the studied parental CMS and DH lines.…”

Heterosis and combining ability in cytoplasmic male sterile and doubled haploid based Brassica oleracea progenies and prediction of heterosis using microsatellites

“…In the present study the PIC content of 87 polymorphic loci ranged from 0.24–0.80, which classified all the 87 loci (g-SSR and EST-SSRs) as slightly informative (1 primer cnu107), reasonably informative (12 primers) and highly informative markers (74 primers). The mean PIC content of 0.63 in present investigation based on 87 genomic-SSR and EST-SSRs was higher than the mean PIC of 0.316 observed for 165 cauliflower inbred lines by Zhu et al [84] and 0.60 as recorded for 57 genotypes of Brassica oleracea comprising 51 cultivars of cauliflower by Zhao et al [85]. The DH lines developed through microspore culture are very diverse from most of the CMS lines.…”

Genetic Diversity and Population Structure Analysis of Chinese Wild Grape Using Simple Sequence Repeat Markers

“…PRINCIPAL COORDINATE ANALYSIS. PCA was chosen to complement the cluster analysis information and genetic relationships (Zhu et al, 2018). The PCA results for 100 accessions based on the genetic distance matrix data from the nine SSR markers is shown in Fig.…”

“…In addition, a population structure analysis showed that five populations were obtained from the 100 Vitis accessions. However, there were a few discrepancies between the cluster analysis and the structure analysis, which might be because each accession was assigned a fixed branch by cluster analysis, whereas the structural analysis assigned individuals to groups based on the percentage of population members (Zhu et al, 2018). The admixture of all the populations might indicate gene flow in these accessions (Aradhya et al, 2013).…”