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31.
运用SRAP分子标记技术分析了80份西瓜种质资源的遗传多样性,28对不同的引物组合共扩增出308条谱带,其中多态性谱带68条。引物组合的多态性频率最低为9.1%,最高为45.5%,平均22.1%。基于全部材料的SRAP基因型数据评价品种间的遗传关系,80份西瓜种质的遗传相似系数变化范围在0.94~1.00之间,表明供试西瓜种质资源的遗传背景比较狭窄。利用NTSYS软件聚类分析,80份西瓜材料被划分为3个类群,类群间相似度较高。来源地不同的西瓜材料也被划分到一个类群,进一步说明供试材料遗传背景狭窄。西瓜育种要取得突破性进展,必须加强种质资源的引进与创新。 相似文献
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Plasmodiophora brassicae is an obligate biotroph that causes clubroot, one of the most damaging diseases of crucifers. Differential cultivars and random amplified polymorphic DNA markers were used to assess the extent of genetic diversity among nine single-gall populations of P. brassicae and 37 single-spore isolates (SSI) derived from four of those field samples. Isolates were classified into eight pathotypes, and each isolate was associated with a unique molecular genotype. Virulence and DNA polymorphisms were detected within and between field isolates, and among SSIs from different pathotypes, hosts and geographical origins. The relatively high level of genetic diversity among field isolates was similar to that among SSIs derived from a single-club field isolate. Molecular and pathogenicity-based classifications were not clearly correlated, but isolates belonging to pathotype P1 were clustered. Two RAPD markers were specific to pathotype P1. The finding that genetic differences can occur in P. brassicae field isolates will be an important consideration in resistance genetic studies and in choosing breeding strategies to develop durable clubroot resistance. 相似文献
35.
J.?LichtenzveigEmail author P.?Winter S.?Abbo D.?Shtienberg W.?J.?Kaiser G.?Kahl 《Phytoparasitica》2002,30(5):467-472
A genetic map was developed for the ascomyceteDidymella rabiei (Kovachevski) v. Arx (anamorph:Ascochyta rabiei Pass. Labr.), the causal agent of Ascochyta blight in chickpea (Cicer arietinum L.). The map was generated with 77 F1 progeny derived from crossing an isolate from the U.S.A. and an isolate from Syria. A total of 232 DAF (DNA Amplification
Fingerprinting) primers and 37 STMS (Sequence-Tagged Microsatellite Site) primer pairs were tested for polymorphism between
the parental isolates; 50 markers were mapped, 36 DAFs and 14 STMSs. These markers cover 261.4cM in ten linkage groups. Nineteen
markers remained unlinked. Significant deviation from the expected 1:1 segregation ratios was observed for only two markers
(Prob. of χ2<0.05). The implications of our results on ploidy level of the asexual spores are discussed.
http://www.phytoparasitica.org posting Sept. 5, 2002. 相似文献
36.
Lobetti R Dvir E Pearson J 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(1):63-68
This study compared the sensitivity of ECG and cardiac troponins to predict cardiac histopathological changes, clinical severity, and survival in canine babesiosis. One control group (n = 9) and 4 groups of dogs with mild uncomplicated babesiosis (n = 8), severe uncomplicated babesiosis (n = 9), complicated babesiosis (n = 8), and babesiosis and concurrent immune-mediated hemolytic anemia (IMHA) (n = 9) were studied. A 1-minute lead II ECG was recorded, and cardiac troponin I (cTnI) and T (cTnT) concentrations in plasma were measured. cTnI concentrations were significantly higher in the complicated (mean, 9.9; SE, +/-5.76) and concurrent IMHA (mean, 6.53; SE, +/-4.32) groups and in the 3 dogs that died of the disease (mean, 22.17; SE, +/-12.85) than in the control dogs (concentration below detection limit of test, -0.3 ng/mL). The 3 nonsurvivors had the most severe cardiac histopathological changes, but no arrhythmia and minimal other ECG changes. Dogs with babesiosis developed a variety of ECG abnormalities, but the abnormalities were not associated with disease severity, outcome, or plasma cardiac troponin concentrations. The exception was the presence of ventricular premature complexes (VPCs), which were associated with high cardiac troponin concentrations. This study showed an association between cTnI concentration and histological changes, clinical severity, and survival and no correlation between ECG abnormalities and histological changes or biochemical evidence of myocardial damage as reflected by cTnI concentrations. From this study, it was concluded that the analysis of plasma cTnI is a feasible and sensitive test and is superior to cTnT in diagnosing cardiac involvement in dogs with babesiosis. 相似文献
37.
OPAY02型2条多态性条带经克隆、测序和引物设计后,转换成SCAR标记,并对86个新扬州鸡随机交配后代基因组DNA进行了PCR扩增.2条带DNA序列与红色原鸡基因组序列比对结果表明,大分子量条带与位于红色原鸡第3号染色体上序列有98%的同源性,共检测到8个SNPS,其中195位的碱基T→G,316位的A→T,538位的G→A,731位的T→A,1 147位的G→A,1 329位的T→C,1 927位的C→T,2 081位的C→T,小分子量条带与红色原鸡没有同源序列,推测新扬州鸡野祖除红色原鸡外,还有其它来源.SCAR标记分析表明,经条件优化随机扩增的OPAY02型标记稳定、可靠,可用于遗传分析.2条带所在座位群体基因型平衡性测验结果表明,所测新扬州鸡群体处于平衡状态,选择可以打破平衡,有利于动物育种. 相似文献
38.
An experiment was conducted with Saanen goats fed fresh grass ad libitum to compare 51Cr-mordanted fibre and even-chain alkanes sprayed onto either grass leaves or stems to estimate faecal output, total mean retention time (TMRT) and parameters obtained from faecal marker concentration curves, such as k1 (slow rate of passage), k2 (fast rate of passage) and transit time (TT). 51Cr-mordanted grass showed the lowest fractional rates of passage (k1 and k2) and hence the largest value of TMRT. There were not significant (P > 0.05) differences between even-chain alkanes sprayed onto leaves or stems for k2, TT and TMRT, but k1 estimates were higher (P < 0.05) for stems than for sprayed leaves. Despite the marker used, TMRT values were negatively correlated with the level of dry matter intake (r = − 0.81, − 0.80 and − 0.80 for 51Cr-mordanted fibre and even-chain alkanes adsorbed onto leaves or stems, respectively). Average faecal outputs estimated from faecal concentrations of 51Cr-mordanted fibre and even-chain alkanes were not different from the actual outputs but there were differences between markers in the accuracy of estimation. The highest mean square prediction error (MSPE) and the poorest correlation between observed and estimated faecal output values corresponded to even-chain alkanes adsorbed onto stems. Values estimated using 51Cr-mordanted fibre and even-chain alkanes adsorbed onto leaves were significantly correlated with faecal outputs (r = 0.94 and r = 0.92, respectively), with MSPE being greater for the latter marker. 相似文献
39.
微卫星序列是以1~6个短核苷酸为基本重复单位的重复序列,呈共显性、重复性好、多态性丰富和操作简单,在基因定位与QTL分析、亲权分析、分子标记辅助选择等方面应用广泛.本文综述了与肉牛部分经济性状(生长发育性状、胴体性状、肉质性状、多胎性状和出生重)相关的微卫星标记研究进展. 相似文献
40.
Sebastjan Radišek Jernej Jakše Branka Javornik 《European journal of plant pathology / European Foundation for Plant Pathology》2006,116(4):301-314
Verticillium wilt, caused by Verticillium albo-atrum or V. dahliae, is an important disease of many worldwide crop species. In Europe, V. albo-atrum isolates infecting hop express different levels of virulence, inducing mild or lethal disease syndromes, and it is therefore an attractive model for studying the virulence of this pathogen. In this work, eleven amplified fragment length polymorphism (AFLP) primer combinations were used to analyze genetic variability among 55 V. albo-atrum hop isolates from four European hop growing regions, as well as isolates from other hosts and V. dahliae isolates. Cluster analysis divided V. albo-atrum and V. dahliae isolates into two well-separated groups. Within the V. dahliae cluster, isolates were separated without host specific grouping, although no host adapted isolates were included. In V. albo-atrum, the alfalfa isolates were distinct from isolates of other hosts, where a high association with virulence was observed in hop and tomato isolates. All lethal hop isolates were genetically different from mild hop isolates. The lethal hop isolates from England and Slovenia expressed the same virulence phenotype, although they showed a different AFLP pattern. The mild hop isolates formed two subgroups, to which isolates clustered irrespective of geographical location. These data suggest multiple origins of V. albo-atrum hop isolates, and the possible appearance of new virulent isolates in the future in other hop growing regions. 相似文献