三种药用车前的染色体数目和核型的研究

<正> 车前为常用中药材,《神农本草经》和明李时珍的《本草纲目》中列为上品,以干燥全草及种子入药,有清热、明目、利尿、止泻、降低血压和镇咳祛痰等功效。 本文报道了作为“车前”中药材的三种车前属Plantago L.植物:大车前P. major L.车前P. aslatica L. 和平车前P. depressa Willd.染色体数目和核型的资料,旨在为探讨车前属内的分类和进化及为提高车前中药材的产量和质量的研究提供必要的细胞学资料。

CHROMOSOME NUMBER AND KARYOTYPE STUDY IN THREE SPECIES OF THE MEDICINAL PLANTAIN

The medicinal plantain, including Plantago major L., P. asiatica L. and P. depressa Willd., is a traditional Chinese medicine having been used since very ancient times. The present paper deals with a study of the chromosome numbers and karyotypes for the above three species. 1. Plantago major and P. depressa.Seeds used for examination were from Wuzhong of Ningxia Autonomous Region for P. major, and from Meixian of Guangdong Province for P. depressa. The somatic chromosome number of both species is 2n = 12, in accord with those reported by many previous authors . Their somatic complements are neayly all of me tacentric chromosomes (Tables 1 and 2; Figs. 2: a,b and 4: a,b), and belong to Stebbins' "lA" type of karyotypic asymmetry. According to McCullagh , the somatic complements of P. major and P. depressa are both 2n = 12 = 2m + 2sm + 6st + 2t (SAT). The karyotype formula for the same species reported by Jain is 2n = 12 = 2m + 6sm + 2sm (SAT) +2st. The present finding is not in accord with their results.Jain held that the infraspecific, genetically different variants of P. major did not show any specific differences in chromosome morphology. He, then, arrived at the point that the diversity distinguishing the variants had been produced by simple gene differences. But the fact that the karyotype of Chinese P. major being strikingly different from those reported by McCullagh and Jain shows clearly that the existence of karyotype differentiation within the species in question.2. Plantago asiatica.Seeds used for examination were from Guangrao of Shandong Province. The somatic chromosome number is 2n = 36(scarcely 2n = 12), in accord with most of the previous reports. But a few authors reported 2n = 24. If take n = 6 to be the basic chromosome number of Plantago ,P. asiatica will be a hexaploid. But McCullagh took the basic number of P. japonica Franch. et Savat , a closely allied species of P. asiatica, to be n= 9, which probably arose from the allopolyploidy of n = 5 and n = 4. However the occurrence of 2n = 24 and 12 within P. asiatica seems to us that taking 6 to be the basic number of the species is more desirable.