Karyotype Analysis of Brassica Napus CV. Huayou No.2

摘要

Brassica napus is one of the important oil crops in the world and has important economic value, B. napus cv. Huayou No.2 has excellent characteristics of resistance to lodging and disease, and has been widely cultivated in all provinces of the Yangtze River Basin and Yunnan-Guizhou Plateau in China. In this research, we try to obtain cytological parameters on 'Huayou No.2'. Seven chromosomal parameters were measured and calculated: chromosome length, relative length, index of relative length, type of relative length, arm ratio, centromere index, centromere type. The experiment results showed that the maximum chromosome length was measured 2.70 μm and max arm ratio was determined 2.12, relative length ranged between 3.54%-7.07%. There are fout types of relative length, including long (L), medium long (M2), medium short (M1) and short (S) chromosomes. In addition, the maximum centromeric index was measured in 47.70%, centromere type included submetacentric (sm) and metacentric (m) chromosomes. Karyotype asymmetry index was 60.52%, and the karyotype formula was 2n=38=28m+10sm (2SAT). The karyotype characteristics were type 2A according to Stebbins's classification criteria. The findings revealed its karyotypic characteristics of 'Huayou No.2' from the cytogenetic aspects.