紫茎泽兰新型抑制剂的筛选

采用PCR-SSCP技术与mtDNAD-Loop序列分析相结合的方法，对我国云南昭通绵羊、腾冲绵羊、宁蒗绵羊3个地方绵羊品种共134个个体进行mtDNA序列多态性及起源进化研究。PCR-SSCP分析显示，在云南的3个绵羊群体中检测到线粒体编码区的Cytb和ND2基因的2种单倍型A和B。根据不同的单倍型从3个绵羊群体中共筛选出23个样品进行了mtDNAD-Loop区克隆测序，系统发育分析揭示袁，云南绵羊mtDNAD-Loop序列单倍型分为支系A和支系B两大类。基于PCR-SSCP和D-Loop区序列的分析结果一致提示云南绵羊存在支系A和支系B两大母系起源，对云南绵羊进行mtDNA D-Loop序列多态性分析，结果发现线粒体D-Loop区系列单倍型多样度Hd为87.5%～100%；核苷酸多样度Pi为0.21～0.26；平均核苷酸差异数k为22.9%～36.8%。此结果揭示云南绵羊遗传多样性相对贫乏遥对云南绵羊mtDNA D-Loop进行Mismatch分析和Tajima'sD值中性检验，结果显示，云南绵羊群体核昔酸差异数表现出完整的2个峰形，且经过中性检验不显著，由此推断云南绵羊在过去没有出现群体扩张，群体大小保持稳定。

Selection of New Herbicides for Control of Eupatorium adenophorum

Mitochondrial DNA (mtDNA) diversity of 134 individuals of three indigenous sheep breeds in Yunnan was analyzed by PCR-SSCP technology and mtDNA D-Loop sequences. The three indigenous breeds included Tengchong, Zhaotong, and Ninglang sheep. PCR-SSCP analyses revealed that two genotypes, A and B, of mitochondrial Cytband ND2genes were detected in the three indigenous breeds. The mtDNA D-Loop sequences of 22 individuals chosen from the three according to different genotypes were sequenced. Phylogenetic analysis indicates that two mtDNA lineages A and B are in Yunnan sheep. These results from PCR-SSCP and D-Loop sequences consistently indicate that Yunnan domestic sheep are derived from two maternal origins of A and B. In addition, the D-Loop sequences analyses show that the Haplotype diversity varies from 87.5% to 100%, nucleotide diversity from 0.21 to 0.26, and average number of nucleotide differences from 22.9% to 36.8% . Polymorphism analyses show that genetic diversity in Yunnan sheep is poor. According to Fu's and Tajima's D test and mismatch distribution analysis, the three indigenous breeds have not been subject to population expansion, suggesting that the population of Yunnan sheep be stable.