A Preliminary Study On The Key Technology Of Giant Knotweed Breeding

The Chinese medicinal Polygoni cuspidati rhizoma et radix is the dried root and rhizome of Polygonum cuspidatum Sieb.et Zucc grown in the humid environment. With the improvement of medicinal and economic value and the deepening research, Polygonum cuspidatum resource is paid much attention, however, drought resistance research has not been reported.To screen out valuable drought-resistant varieties,we make a drought resistance assessment,establish and develop iPBS molecular marker about Polygonum cuspidatum materials from six areas. The study lay the foundation for large-scale cultivation, provide the basis for germplasm management, the core collection established and breeding of Polygonum cuspidatum.We utilize morphologic and physiology knowledge to research the drought-resistant Polygonum cuspidatum from5areas and establish drought evaluation system, which will promote the drought-resistant breeding study of Polygonum cuspidatum. The results showed that:1. Polygonum cuspidatum from different origin are similar in shape, but the leaf area and leaf angle are quite different. The drought resistance ability sequence of Polygonum cuspidatum from large to small is as follows:Yao zhiyuan> Du jiangyan>Bazhong>Ganzi>E’mei Polygonum cuspidatum;.2. We emulation Polygonum cuspidatum water stress in laboratory, relative water content (RWC) descend, water saturation deficit (WSD) rise, malondialdehyde (MDA)is slightly different in different varieties, the peroxidase oxidase (SOD) and osmotic adjustment substances Preserved acid (Pro) show a downward trend, peroxidase (POD), catalase (CAT) activity showed an upward trend with poly (ethylene glycol)-6000(PEG-6000) concentration increases;3.The results of physiological indicators of the different varieties of Polygonum cuspidatum is consistent with the results of the morphological index by subordinative function.In order to explore the application of new molecular markers in the breeding of Polygonum cuspidatum, we research the genotypic polymorphism among9germplasm resources from6areas in Sichuan province with iPBS analysis.22iPBS primers with higher polymorphism were screened out from50iPBS primers;66.5%bands displayed polymorphism among the total161identified bands.Each primer amplified an average of4.86polymorphic fragment. The cluster analysis shows that the materials can be separated by iPBS analysis.When GS equal to0.79,all accessions can be ascribed into5groups. The results show that much genetic25diversity on molecular level among the germplasm resources of Polygonum cupidatum is existed; genotype is closely related to regional.The results provided valuable information for the classification and breeding of Polygonum cuspidatum germplasm resources.The preliminary study on breeding of Polygonum cuspidatum will help filter out valuable drought resistance variety of Polygonum cuspidatum. Because of the special nature of medicinal plants, their quality plays a decisive role. This study identified the superior drought resistance variety of Polygonum cuspidatum and lay the foundation for comprehensive breeding, the drought resistance breeding and composition breeding of Polygonum cuspidatum.This reserch provide the basis for germplasm management, the establishment of the core collections and breeding of Polygonum cuspidatum.