| The genetic diversity and the feeding value and drought tolerance of wild Hemarthria compressa from southwest China were studied. The genetic variation of twenty-eight and fouty-five wild accessions were evaluated by ISSR and SRAP, repectively. The production ability and feeding value of H. compressa with a pre-selection were also assessed by the yield and quality, compared with the check cultivars'Chonggao'and'Guangyi'. Finally, the drought tolerance of materials was also evaluated. The results were as follows:1. Inter-simple sequence repeat (ISSR) method was applied to detect genetic variation of 28 Hemarthria compressa accessions from Southwest China (Sichuan, Chongqing and Guizhou Province). Thirteen primers were selected from 96 ISSR primers, and 129 DNA fragments were amplified from 28 samples. Of which,110 fragments were polymorphic (percentage of polymorphic bands was 84.2%), and the average number of DNA bands was 9.9 per primer. The genetic similarity among all accessions ranged from 0.466 to 0.980, which indicated that the genetic diversity was comparatively rich among the tested accessions. UPGMA cluster based on genetic similarity and principle component analyses (PCoA) based on band patterns divided the accessions into two groups corresponding to their geographical sources.2. The sequence-related amplified polymorphism (SRAP) was applied to detect genetic diversity of 43 Hemarthria compressa accessions mainly from Southwest China (Sichuan, Chongqing, Guizhou and Yunnan province). Eleven primer pairs were selected for amplification, and 153 DNA fragments were generated, of which 140 bands were polymorphic and the average number of bands were 13.91. The genetic similarity coefficient (GS) among all accessions ranged from 0.565-0.992 with the mean of 0.723, which also indicated that the genetic diversity was comparatively rich among the accessions tested. The cluster of H. compressa related to the geographic origins, ecological types and morphological characteristics of the accessions. Moreover, the result of principal coordination analysis (PCoA) intuitively indicated the genetic relationships among the materials. AMOVA revealed that 85.99% of total variation occurred within the groups, and 14.01%of total variation occurred among the groups, with 0.140 forΦST value. The results of the study could supply references for the collecting, breeding and conservation of H. compressa.3. The production ability of twenty-seven H. compressa accessions was compered with the stability and adaptability at Qiaoping in Chongqing, compared with the check cultivars of'Guangyi'and'Chonggao'during 2004-2006. The six materials selected from the comparison were selected for further evaluating at Nanchong, Meishan, Rongchang regions. Finally, the H2003-5 was selected as the elite accession with the high yield and good quality.4. The feeding value of fourteen H. compressa accessions was assessed. The results showed that:(1) seven accessions displayed the better feeding value than check cultivar based on analytical hierarchy process(AHP), which was 2002-2, 2002-4,2003-3,2003-6,2003-5,2003-2,2003-4; (2) the gray relation analysis showed that 2003-5 was the most similar to check cultivar, then 2003-4,2002-6, 2002-1,2002-5, H002,2003-6,2003-1,2002-2,2003-3,2002-4 had the similar characters to check cultivar, and 2003-2,2002-3, H019 had the different characters from the check cultivar.5. Under the controlling of water, the drought tolerance of twenty H. compressa was comprehensively evaluated with the method of membership function using 8 indices including the relative plant tall, relative production. The result of tolerance order showed that:'Guangyi'> H027> 2002-4> H042> H054> 2003-5> H055> H002> H035> 2003-1> H050>'Chonggao'> H031> H047> H043> H033> H036> 2003-4> H019> H029. Furthermore, the correlation analysis between the tolerance and indices showed that there was a significant correlation between the tolerance and relative production, electrical conductivity, water content.
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