Parasitic relationship of Cistanche deserticola and host-plant Haloxylon ammodendron based on genetic variation of host

Objective: Cistanche deserticola is a famous and endangered medicinal plant that is parasitic upon Haloxylon ammodendron with rather low parasitic rates. It is important to find high affinity germplasms for increasing the survival of C. deserticola. However, little is known in genetic variation and high affinity populations of H. ammodendron in China. Methods: In this study, 98 accessions of H. ammodendron seeds were collected from five regions covering almost the entire natural distribution of H. ammodendron in China. Their genetic variations were analyzed using AFLP and ITS by the maximum parsimony method, and a dendrogram was constructed using the unweighted pair-group method with arithmetic average (UPGMA). The parasitic rates of C. deserticola on different accessions of H. ammodendron were calculated in the field experiment. Results: Both AFLP and ITS methods consistently revealed that there was a high level of genetic diversity in the natural populations of H. ammodendron. Hierarchical population structure analysis uncovered a clear pattern that all populations were grouped into three main clusters, and eight populations from eastern region were genetically clustered together. These regions were significantly differentiated (P < 0.05), 13.10% of variation occurred among populations, and 86.90% within populations was revealed by analysis of molecular variance (AMOVA). The populations of Inner Mongolia had the highest parasitic rates followed by Ganjiahu Reserve and Yongning Plantation for the top three, which were not completely related to the genetic variation. Conclusion: Genetic characteristics of H. ammodendron in China were clarified and the order of affinity of different populations was given, which were primers for discovering high affinity germplasms. (C) 2019 Tianjin Press of Chinese Herbal Medicines. Published by Elsevier B.V. All rights reserved.