排序方式: 共有140条查询结果,搜索用时 0 毫秒
21.
A new species of Phytophthora, previously referred to as the 'Dre I' taxon, is named Phytophthora irrigata. Isolates of P. irrigata morphologically and physiologically resemble Phytophthora drechsleri. They are heterothallic, produce nonpapillate sporangia, and grow well at 35 degrees C. The above two species differ significantly in uniformity of mycelium, presence of chlamydospores, DNA fingerprint, and sequences of multiple nuclear and mtDNA regions. Phytophthora irrigata produces smaller sporangia and a distinct DNA fingerprint. Sequence alignments in the ribosomal DNA internal transcribed spacer regions place Phytophthora fallax and Phytophthora captisoa as its closest relatives. The optimal temperature for culture growth is above 30 degrees C and the maximum temperature is 40 degrees C. This new species is abundant in irrigation reservoirs and natural waterways in Virginia and was also isolated in Pennsylvania. 相似文献
22.
Sinomanglietia glauca is a critically endangered species described from Jiangxi Province in the 1990s. Recently two populations were discovered from Yongshun County of west Hunan Province, about 450 km away from those in Jiangxi. Because of the new findings and the poor reproducibility inherent to RAPD and ISSR markers of previous studies, the population structure of this rare species was reanalyzed with chloroplast PCR-SSCP (single-stranded conformation polymorphism), including all of four recorded populations. The results showed that two distinct haplotypes characterized Jiangxi and Hunan populations separately, with no genetic variation occurring within regions. We postulated that this surprising pattern might result from habitat fragmenta-tion and demographic bottlenecks during and/or after the Quaternary glaciation. On the basis of the pronounced genetic structure, two evolutionarily significant units (ESUs) were recommended for effective conservation of S. glauca. 相似文献
24.
Gao Y Zhang YH Zhang S Li F Wang S Dai L Jiang H Xiao S Liu D Sun B Zhao Z Zhang JB 《Gene》2011,487(2):170-173
This study was designed to investigate the single nucleotide polymorphism (SNP) in intron 1 of the gene A-FABP in 127 Junmu No. 1 white swine using PCR-SSCP. The association between the polymorphism and meat quality traits was also studied. The cloning and sequencing results indicated that the polymorphism of intron 1 was due to a point mutation in position 3481 bp of A-FABP, giving 3 genotypes (CC, CD and DD). Association analysis indicated that the polymorphism had a significant effect on marbling (P < 0.05). Genotype DD had higher marbling than CD and CC, but the difference between CD and CC was no significant. Polymorphism had a highly significant effect on intramuscular fat (IMF) content (P < 0.01). DD was higher than CD, which was higher than CC. No significant conclusions can be drawn regarding other traits. Immunoblot analysis of A-FABP levels was carried out on 3 different genotype individuals. Expression was markedly reduced in DD compared with genotype CC. Thus A-FABP may be a candidate gene or a quantitative trait locus-linked gene associated with meat quality traits. 相似文献
25.
新疆泥火山细菌群落PCR-SSCP 分析 总被引:1,自引:0,他引:1
采用单链构象多态性(SSCP)技术, 以16S rDNA 基因的V3 区为靶对象, 分析泥火山细菌多样性及其群落结构。通过对泥火山不同月份的不同深度土样DNA 提取后, 针对16S rDNA 进行PCR 扩增出236 bp 大小片段, 通过SSCP 电泳对泥火山细菌进行季节性多样性分析, 并对主要条带进行克隆分析。结果显示: 新疆泥火山细菌不同季节多态性明显, 而且这种多态性容易受生态和气候的影响; 假单胞菌属是泥火山土壤优势菌群, 在泥火山区土壤中广泛分布, 受生态和气候环境影响较小。 相似文献
26.
FGF5基因对内蒙古绒山羊绒毛性状的影响 总被引:2,自引:0,他引:2
根据FGF5基因已知DNA序列设计了2对引物, 采用PCR-SSCP和PCR-RFLP技术, 在内蒙古绒山羊群体中进行基因多态性检测, 结果发现FGF5基因外显子1存在限制性内切酶BglⅠ多态位点。对其不同基因型个体PCR回收产物进行测序, 测序结果发现该SNP是由碱基序列C→T的突变而引起的。基因型和基因频率统计, 该实验群体以等位基因A具有明显的优势, χ2检验表明该SNP位点的基因频率处于Hardy-Weinberg平衡状态; 对该SNP与绒毛性状关联分析, 表明该SNP对绒纤维伸直长度(P<0.01)和含绒量(P<0.05)有显著影响, 而对其他各绒毛性状的影响不显著(P>0.05)。AB基因型个体绒纤维伸直长度(P<0.01)和含绒量(P<0.05)显著高于AA基因型个体。 相似文献
27.
28.
鸡apoA5基因单核苷酸多态性及其与屠体性状的关联研究 总被引:2,自引:0,他引:2
以丝羽乌骨鸡和隐性白洛克正反交产生的F2代为实验群体, 采用PCR-SSCP和DNA测序的方法检测鸡载脂蛋白A5(apoA5)基因的单核苷酸多态性(SNPs), 并将所发现的SNPs与体重、胸肌重、腿肌重、心脏重、肝脏重和腹脂重等屠体性状进行关联分析。结果发现, 鸡apoA5基因5′-调控区C-169T, 外显子2 C600T、T635C, 外显子3 C841G、C914T、C1142G、C1394T共7个突变位点。其中外显子2突变位点C600T、T635C对12周龄腹脂重、腹脂率、肝脏重和心脏重有显著影响(P<0.05), 根据PCR-SSCP的结果将其分为6种基因型(AA, AB, AC, BB, BC, CC): 其中CC型个体的腹脂重和腹脂率显著高于AA型、AB型、AC型、BB型、BC型 (P<0.05); AC型个体的肝脏重显著低于AA型、AB型、BB型、BC型和CC型的肝脏重(P<0.05); BC型个体的心脏重显著低于BB型的心脏重(P<0.05)。 相似文献
29.
摘要: ZAG基因的功能主要是促进脂肪分解, 减少脂肪含量。文章利用PCR-SSCP和DNA测序技术研究了145头郏县红牛ZAG基因编码区4个位点(Z1、Z2、Z3、Z4)的多态性, 发现Z1、Z3、Z4 位点存在SSCP多态。对不同SSCP带型的对应片段进行了测序分析, 共发现6个新的SNP多态位点(C115T、A3257G、A4013G、T4027C、C4032T、T4120C)。Z3位点处于Hardy-Weinberg平衡状态, Z1、Z4 位点处于非平衡状态。不同基因型与生长发育性状的相关性分析显示, Z4位点上, AC基因型个体的体斜长、胸围、管围、体重指标显著(P<0.05)或极显著(P<0.01), 大于AA、AB基因型个体, 暗示该位点有可能作为郏县红牛生长性状标记辅助选择的标记之一。 相似文献
30.