[Karyotype analysis of Gentiana straminea]

Study on chromosome number, karyotype of Gentiana straminea for the first time. Compare karyotypes of Gentiana straminea, Gentiana macrophylla and Gentiana dahurica. Provide cytological evidence for further studies on genetics and evolution.

Soak the root tip in 0.002 mol/L 8-oxychinolin solution for 5.7 h. Decomposed in 2.5% mixed enzyme solution for 1.6 h at 25 degrees C and use Hypotonic treatment for 3 h in refrigerator. At last, make specimen slides by the Air-drying technique. Sections combined with micrograph were used to analyze chromosome.

The karyotypes formula of Gentiana straminea is K(2n) = 26 = 2M + 24 m, the AS. K was 52.68%, which belong to "1A" type.

Compare karyotypes of Gentiana straminea, Gentiana macrophylla and Gentiana dahurica, the result showed that Gentiana macrophylla lives in highest stage of evolution. Gentiana straminea is intermediate between Gentiana macrophylla and Gentiana dahurica.