Karyotypes and C-values of Two Plantago Species from the Qinghai Tibet Plateau,China

The chromosome numbers, karyotypes and C values of 18 populations of Plantago depressa and 2 populations of Plantago major from the Qinghai Tibet Plateau, China, were reported in the present study. The results were as follows: the chromosome numbers of P. depressa populations from Yadong County and Nyingchi County of Tibetan Autonomous Region (TAR) were 2n=4x=24, other populations of Pdepressa and Pmajor were 2n=2x=12, and the basic chromosome number of all populations was x=6. All karyotype types were 1A, and the karyotype constitutions were not completely consistent with previous reported results. The 2C value of Pdepressa was reported for the first time, and the 1Cx vaule tended to decrease with increasing ploidy levels. Meanwhile, the 2C value of Pmajor was not identical with previous existing results. The results showed that the variation of 2C value occurred at the inter population level of Pdepressa and Pmajor, also flow cytometry couldn′t be used to estimate the ploidy of the genus Plantago Linn.