Karyotype Analysis of Cypripedium japonicum Thunb. and Calanthe tsoongiana T. Tang et F. T. Wang

Abstract:

The aim was to understand the karyotype of Cypripedium japonicum Thunb. and Calanthe tsoongiana T. Tang et F. T. Wang. Their chromosome number and karyotype were studied by using fingertip squashing method. The results showed that the chromosome number of Cypripedium japonium was 2n = 22, karyotype formula was 2n = 2x = 22 = 16m + 2sm + 2st + 2t, constitution of relative length was 2n = 22 = 2L + 6M₂ + 12M₁ + 2S, asymmetry index was 60.01%, karyotype type was classified as 2B; while the chromosome number of Calanthe tsoongiana was 2n = 40, karyotype formula was 2n = 2x = 40 = 28m + 10sm + 2st, constitution of relative length was 2n = 40 = 8L + 10M₂ + 16M₁ + 6S, asymmetry index was 59.84%, karyotype type also belonged to 2B. Both of them have relatively symmetric karyotype. The karyotype of Calanthe tsoongiana was reported for the first time. These provided some cytological evidences for evolutionary status and germplasm conservation of Cypripedium japonicum and Calanthe tsoongiana.