Analysis of F_1 hybrid and BC_1 monosomic alien addition line plants from Brassica oleracea x Sinapis alba by GISH

摘要

Sterile and semi-fertile F_1 plants were obtained by intergeneric sexual hybridization between paternal Brassica oleracea var. alboglabra (genome CC, 2n = 18) and maternal Sinapis alba (genome SS, 2n = 24), BC_1 plants were obtained by backcrossing between paternal B. oleracea and maternal semi-fertile F_1 plants. Genomic in situ hybridization (GISH) combined with dual-colour fluorescence in situ hybridization (dcFISH) showed that sterile F_1 plants contained 21 chromosomes consisting of one B. oleracea chromosome set and one S. alba chromosome set, belonging to expected hybrids, and semi-fertile F_1 plants contained 30 chromosomes consisting of two B. oleracea chromosome sets and one S. alba chromosome set. It is obvious that the semi-fertile F_1 plants belong to unexpected hybrids. 1-3 trivalents were detected at meiotic metaphase Ⅰ of semi-fertile F_1 pollen mother cells (PMCs). Different separation ratios of S chromosomes were detected at anaphase Ⅰ. A monosomic alien addition line (MAAL) was identified by GISH-dcFISH from BC_1 plants; it contained 19 chromosomes consisting of 18 C chromosomes and 1 S chromosome. At meiotic metaphase Ⅰ, 9 divalents from B. oleracea and one univalent from S. alba could be detected. Sometimes, one putative C-S trivalent could also be detected. The achievement of B. oleracea-S. alba monosomic alien addition lines lays a foundation for gene introgression, location and cloning.