Studies On Allelopathic Potential In Barley(Hordeum Vulgare)Gemplasms And Their Genetic Diversity

The application of allelopathy is an alternative weed control method that could be incorporated into integrated weed management package, thereby reducing over-reliance on herbicides and decreasing environmental pollution. Research in this area has been receiving increasing attention in the world. In this paper, a laboratory screening was conducted to study the allelopathic potential of 289 spring barley accessions from home and abroad by RCA bioassay method. Then the ability of weed-suppressing and agronomic characters were evaluated in the field. Genetic diversity of 65 representive barley varieties was estimated using ISSR markers. The results were summarized as follows:1. Of 289 barley accessions, 36 accessions showed strong allelopathic potential by significantly inhibiting root growth of Lettuce(Lactuca sativa L.) in the laboratory screening.One accession inhibited the growth of receiver plant by 91.5%, whereas 35 other accessions caused growth inhibition by more than 70%.53 cultivars were found to strongly suppress weed growth in the fields. Several cultivars such as M24, Xingsheng and Yong 2176 performed stong allelopathy potential in the laboratory screening and the same result was found in the field screening.Correlation between the laboratory screening and the field experiment showed that field performance could be predicted to some extent by Lactuca sativa L root length reduction in the laboratory. The result demonstrated that there was a considerable genetic variation of alllelopathic activity in barley germplasms and the alllelopathic activity was easily affected by environment.2. At the level of D=10.8, 65 barley varieties were clustered into six groups.The second group consisted of 17 accessions, showing strongly allelopathic in it, of which 15 ones performed more than70% inhibition in the suppression on the receive plant. They were thought to be a potentially useful source for the research on barley allelopathy and the breeding program for allelopathic cultivars. The third group included 22 accessions which could be divided into 3 subgroups. The third subgroup included 3 accessions such as Fan 18, CM67 H0651 and M13, which averaged 1R value was 31.7%. They still...