ZHANG Shu-ning, ZHANG Hong-mei, ZHENG Jin-shuang, KONG Yan-e, WANG Jian-jun
College of Horticulture, Nanjing Agricultural University, Key Laboratory of Southern Vegetable Crop Genetic Improvement, Ministry of Agriculture, Nanjing 210095, Jiangsu, China
Abstract：Karyotype analysis and comparison of 7 subspecies of cole crops were conducted by traditional squash method. The results showed that broccoli（Brassica oleralea L.var. italica P.）：2n=2x=18=8m+10sm（2SAT）, satellites were observed at the 6th pair of chromosomes; cabbage（Brassica oleralea L. var. capitata L.）: 2n=2x=18=8m+10sm（2SAT）, satellites were observed at the 6th pair of chromosomes; cauliflower（Brassica oleralea L. var. botrytis L.): 2n=2x=18=12m+6sm（2SAT）, satellites located in the 7th pair of chromosomes; cabbage mustard（Brassica alboglabra L. H. Bailey）: 2n=2x= 18=8m+10sm（2SAT）, satellites were observed at the 7th pair of chromosomes; brussels sprouts（Brassica oleralea L. var. germmifera Zenk.）: 2n=2x=18=8m+10sm（2SAT）（first time to be reported）, satellites were observed at the 7th pair of chromosomes; collard（Brassica oleralea L. var. acephala DC.): 2n=2x= 18=10m+8sm and kohlrabi（Brassica oleralea L. var. caulorapa DC.）: 2n=2x=18=8m+10sm, no satellites were observed at these two subspecies. The karyotype type of all subspecies belong to 2A, presenting a ultimately symmetry karyotype. But the evolution extent is inconsistent among different subspecies. In addition，we also discussed about the genetic relationship and genetic diversity of cole crops.
