Karyotype analysis of Camellia sinensis cv. Chuannong-Huangyazao

Chuannong-Huangyazao’ is a new yellow tea variety bred by Sichuan Agricultural University, and approved by Sichuan Crop Variety Validation Committee in 2009. In this research, we try to obtain cytological parameters on ‘Chuannong-Huangyazao’. Seven chromosomal parameters were measured and calculated: chromosome length, relative length, index of relative length, type of relative length, arm ratio, centromere index and centromere type. The experiment results showed that the max arm ratio was determined 5.54, relative length ranged between 4.69% to 6.83%. There are four 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 43.11%, there were seven pairs of submetacentric chromosomes (sm), six pairs of centromere types were metacentric chromosomes (m) and two pairs of centromere types were subterminal chromosomes (st). Karyotype asymmetry index was 64.902%, and the karyotype formula was 2n=2x=30=12m+14sm (2SAT) +4st. The karyotype characteristics was type 2C according to Stebbins’s classification criteria. According to the above information, we can draw a conclusion that ‘Chuannong-Huangyazao’ is a relatively evolved tea variety. The findings revealed its karyotypic characteristics of ‘Chuannong-Huangyazao’ from the cytogenetic aspects.