[Study on phenotypic diversity and cluster analysis of Cistanche Herba in different populations in Xinjiang]

To intuitively understand the phenotypic diversity of intra-population and inter-population of the medicinal Cistanche Herba distributed in Xinjiang province, three species of Cistanche Herba were selected for the first time to be conducted to phenotypic observation and measurement from the morphological perspective, aiming to fill the gap in the morphological research concerning Cistanche Herba, and discuss about the relationship between the phenotypic variation and the host plants together with the geographical conditions, thus better understanding the speciation and evolutionary mechanism of Cistanche Herba and providing some scientific basis for the resource protection and germplasm breeding of Cistanche Herba. Based on sampling survey, a total of 118 well grown medicinal Cistanche samples from 17 Cistanche Herba distribution areas in Xinjiang province were selected, and various indexes were observed and measured. Besides, ANOVA and clustering analysis were conducted with 9 phenotypic quantity characters. The Cistanche Herba was plentiful in phenotypic variation. For detail, significant intra-population differences were observed in eight of the nine character indexes, and the intra-population differences were more obvious than those of inter-population. For each quantity character of the three species, the flower density possessed the maximal variable coefficient (71.1%) while the flower length was the minimum (15.9%). The phenotypic variation was also obvious among different populations. Specifically, the average variable coefficient of flower number was the maximal one (46.5%) and the flower length was the minimum one (10.0%). For different populations, the average variable coefficient of the D4 population was the maximal one (41.1%) and the S3 population was the minimum one (13.5%). According to the clustering analysis, all the samples of Cistanche Herba could be divided into three groups when the Euclidean distance was set at 15. The populations of S1, S3, D1, S2, D4, D6, D7 and D5 which distributed in the north of Xinjiang were clustered into one group, and the populations of D8, S4, D9, D2 and D3 that grown in east and central of Xinjiang were clustered into another group. The populations of C. deserticola and C. salsa could not be completely separated, but both of them were obviously differentiated from the T1, T3 and T2 populations of C. tubulosa. Besides, the C. deserticola and C. salsa displayed a patch distribution among different populations, and similar phenotypic characters were shared for each population. The research results of phenotype were consistent with that of molecular biology study of Cistanche Herba. The different phenotypic characters in different distribution areas were deduced to be arose from geographical isolation caused by mountains, which led to the specific genetic structure for each population of Cistanche Herba during the long-term adaptation and evolution. In conclusion, the current study showed the adaptation potency of Cistanche Herba exposed to different habitats.