Molecular Markers for Detecting Inflorescence Size of Brassica oleracea L. Crops and B. oleracea Complex Species (n = 9) Useful for Breeding of Broccoli (B. oleracea var. italica) and Cauliflower (B. oleracea var. botrytis)

The gene flow from Brassica oleracea L. wild relatives to B. oleracea vegetable crops have
occurred and continue to occur ordinarily in several Mediterranean countries, such as Sicily, representing
an important hot spot of diversity for some of them, such as broccoli, cauliflower and
kale. For detecting and for exploiting the forgotten alleles lost during the domestication processes
of the B. oleracea crops, attention has been pointed to the individuation of specific markers for individuating
genotypes characterized by hypertrophic inflorescence traits by the marker assisted
selection (MAS) during the first plant growing phases after the crosses between broccoli (B. oleracea
var. italica)/cauliflower (B. oleracea var. botrytis) with B. oleracea wild relatives (n = 9), reducing the
cultivation and evaluation costs. The desired traits often found in several B. oleracea wild relatives
are mainly addressed to improve the plant resistance to biotic and abiotic stresses and to increase
the organoleptic, nutritive and nutraceutical traits of the products. One of the targeted traits for
broccoli and cauliflower breeding is represented by the inflorescences size as is documented by the
domestication processes of these two crops. Based on the previous results achieved, the numerical
matrix, obtained utilizing five simple sequence repeats (SSRs), was analyzed to assess the relationship
among the main inflorescence characteristics and the allelic variation of the SSRs loci analyzed
(BoABI1, BoAP1, BoPLD1, BoTHL1 and PBCGSSRBo39), both for the Brassica oleracea and B. oleracea
wild relatives (n = 9) accessions set. The main inflorescence morphometric characteristics, such as
weight, height, diameter, shape, inflorescence curvature angle and its stem diameter, were registered
before the flower anthesis. We analyzed the correlations among the allelic variation of the SSRs
primers utilized and the inflorescence morphometric characteristics to individuate genomic regions
stimulating the hypertrophy of the reproductive organ. The relationships found explain the diversity
among B. oleracea crops and the B. oleracea complex species (n = 9) for the inflorescence size and
structure. The individuated markers allow important time reduction during the breeding programs
after crossing wild species for transferring useful biotic and abiotic resistances and organoleptic and
nutraceutical traits to the B. oleracea crops by MAS.