Using Simple Sequence Repeats in 9 Brassica Complex Species to Assess Hypertrophic Curd Induction

Five Simple Sequence Repeats (SSRs) were used to assess the relationship between inflorescence
characteristics and their allelic variation in 53 Brassica oleracea and Brassica wild relatives
(n = 9). Curd morphometric traits, such as weight (CW), height (CH), diameter (CD1), shape (CS)
inflorescence curvature angle (CA), and its curd stem diameter (CD2), were measured. The aim of
the work was to analyze the relationships among the allelic patterns of the SSRs primers utilized,
and their status of homo or heterozygosity registered at each locus, as well as the inflorescence
morphometric traits in order to individuate genomic regions stimulating the hypertrophy of this
reproductive organ. The relationships found explain the diversity among B. oleracea complex species
(n = 9) for the inflorescence size and structure, allowing important time reduction during the breeding
process by crossing wild species, transferring useful resistance, and organoleptic and nutraceutical
traits. The five SSRs loci were BoABI1, BoAP1, BoPLD1, BoTHL1, and PBCGSSRBo39. According
to the allelic variation ascertained, we evaluated the heterozygosity index (H) for each SSR above
cited. The results showed a significant interaction between the H index of the BoPLD1 gene and the
inflorescence characteristics, summarized by the First Principal Component (PC1) (p-value = 0.0244);
we ascertained a negative correlation between the H index and inflorescence characteristics, namely
CW, CH, CD1, CD2, CA. The homozygosity BoPLD1 alelles, indicated by the H index, affect the
inflorescence characteristics and broccoli and cauliflower yields.