Studies On Genetic Diversity Of Germplasm Resource Of Houttuyina Thunb.in Hubei

Houttuynia cordata Thunb., which is only the species in the Houttuynia genus and belongs to the family Saururaceae, is a perennial herb and mainly propagated by underground stems. Houttuynia cordata is one of the the medicine-food herbs with the approval of the country’s ministries of Health officially. The whole plant can be used as medicine.Its active contents-Houttuynin has the effect of antibacterial, anti-virus, anti-inflammatory and anti-tumor effect, in the broad clinical application. Its underground stems and ground leafs into nutrient-rich, can act as vegetable consumption.Germplasm Resources of Houttuynia cordata is widely distributed in central and southerns of China. Province of Hubei includeingYichang, Xuan Yan, Enshi, Lichuan, Badong, Xingshan, Fangxian, Xianning, and other counties, is one of the main production areas of houttuynia cordata. In particular, Yichang and Enshi underground stemof this plant is a local favorite vegetables. Wild resources have been introduced for cultivation, however, different region of germplasm have been mixed. The study on houttuynia cordata mainly foucus on the medicinal ingredient, pharmacological and cultivation techniques and other aspects, Genetic diversity studies on germplasm resource of Houttuyina Thunb.in Hubei Province have not been seen.34 germplasm populations were collected and evaluated with genetic diversity.,and the variation of genetic diversity of species were surveyed. The research results were as follows:An assessment to genetic variation of morphological characteristic among 20 Houttuynia cordata germplasm populations was carried. The populations of Houttuynia cordat showed rich genetic variation in the morphological traits. The populations of Houttuynia cordata can be divided into 3 groups by means of cluster grouping with 15 measurable traits.The chromosome numbers of 17 accessions of Houttuynia cordata were observed and counted. The species exhibits highly complex variation in chromosome numbers, the chromosome numbers varying from 36 to 99, of which 99,92,38,37,35 were checked for the first time and among them the chromosome numbers 94 showed highest frequency.To determine the renatinship between the variation of chromosome number and the male sterility, different meiosis behaviors were studied and explored, such as:cytomixis occurred in pollen mother cells (PMCs) during whole process of meiosis at high frequencies and with variable degrees of chromatin/chromosome transfer. The meiotic abnormalities such as chromosome laggards, asymmetric segregation and polyads also prevailed in PMCs at the metaphase of first division and later stages, which were caused by the cytomixis and resulted in the very low pollen viability and male sterility.A collection of 34 Houttuynia cordata populations have been screened with SRAP primers in order to analyze their genetic diversity. The result showed that a relatively high level of genetic variation among the populations, and all the Houttuynia cordata populations could be distinguished by SRAP markers and could divided into 3 groups with UPGMA method.The results implied that the genetic diversity between the Houttuynia cordata populations was correlated with geographic distribution.