甘蓝型油菜含油量的遗传研究

采用7×7双列杂交设计,研究了甘蓝型油菜含油量的基因作用和其它遗传参数,以及含油量与其它农艺性状、品质性状的关系。结果表明:含油量的遗传符合加性—显性遗传模型,有关基因在亲本中呈独立分布;显性指向增效,表现超显性作用;亲本中显性基因比隐性基因多,增效基因比减效基因的频率大;控制含油量并表现显性的基因约为4组;含油量的广义和狭义遗传力分别为81.16％和30.90％。单相关和逐步回归分析一致表明,单株产量、每角粒数、主花序长度和株高对含油量有较强正向作用,但角果长度和全株总角果数的作用为负。本文还讨论了基因作用分析在探讨配合力的基因效应成分和杂种优势产生的可能原因中的意义,及其在选择中的应用。     

基于深度学习的病虫害智能化识别系统

我国农作物种植覆盖面广、分散度高,病虫害发生种类多、区域性发生规律复杂,传统的人工鉴定技术从效率、能力与精度方面均难以满足新形势下重大病虫测报要求。针对这一实践需求,以测报灯下害虫图像数据库(约18万张)、田间病虫害图像数据库(约32万张)为基础,构建了基于深度学习方法的病虫害种类特征自动学习、特征融合、识别和位置回归计算框架,并研发了移动式病虫害智能化感知设备和自动识别系统。通过近2年的精确度和实操运行效率检验,该系统在自然状态下对16种灯下常见害虫的识别率为66%～90%,对38种田间常见病虫害(症状)的识别率为50%～90%。随基础数据库的不断丰富、神经网络深层特征提取的不断完善,该系统有望进一步提高识别准确率,从而真正实现田间病虫害识别自动化、智能化和高效率。     

睾丸支持细胞的功能、分离纯化及鉴定研究进展

支持细胞对维持精子形成过程中的微环境起决定作用,它可以通过分泌功能、细胞间连接形成的血睾屏障功能以及吞噬功能等来促进精子的形成过程,其发育异常会导致不同程度的雄性生殖缺陷。基于支持细胞在雄性动物生殖过程中的作用,体外培养高纯度支持细胞可成为研究睾丸两大核心功能-精子发生和性激素分泌功能相关调节机制重要的细胞模型。此外,体外培养睾丸支持细胞也可作为生殖毒理学等新兴热点领域的细胞模型,为评估和研究环境因素对雄性生殖的影响提供便利。因此,作者系统地归纳、总结了目前关于动物支持细胞生物功能的研究及常用的体外分离纯化、培养及鉴定方法,以期为利用动物支持细胞开展雄性生殖领域的研究提供参考。     

Genetic correlations between similar traits in the Danish and Swedish Warmblood sport horse populations

Genetic correlations between phenotypically similar or related traits tested at young horse performance tests for Danish Warmblood (DWB) and Swedish Warmblood (SWB) horses were calculated using Multi-trait Across Country Evaluation (MACE). Data comprised stallions with an estimated breeding value (EBV) from the national genetic evaluations (NGE) based on at least 10 progeny tested in performance tests, and the ancestors of those stallions in two generations. The DWB data included 349 stallions and the SWB data 426 stallions. Of these, 28 had EBVs in both DWB and SWB. Additionally 151 pedigree animals were common between DWB and SWB. The dependent variables used were NGE results of stallions born 1980 and later, which reduced the number of common stallions with EBVs to 23. The genetic correlations were very high for jumping traits (0.99) and dressage related traits (0.89–0.97). For conformation traits correlations varied between 0.10 and 0.98. Because of the high genetic correlations and frequent use of same or closely related foreign stallions, breeders of both DWB and SWB would benefit from using the NGEs for performance traits across countries, although the genetic correlations do not consider differences in genetic merit levels between the populations. It would be feasible to perform a joint genetic evaluation using MACE, which would improve the reliability of estimated breeding values, and enable ranking of all stallions according to the national scale of each country.     

犊牛大肠杆菌病病原的分离鉴定

从陕西杨凌某发病牛场采取腹泻犊牛病料5份,经微生物学诊断,从中分离出革兰阴性疑似致病菌6株。经生物学特性和生理生化试验鉴定,6株分离菌均为致病性大肠埃希菌。对分离菌进行抗生素敏感性试验,结果表明,该致病菌对氯霉素、菌必治、氧氟沙星、阿米卡星及卡那霉素等高度敏感;对妥布霉素、呋喃妥因和复达欣等中度敏感,对链霉素、庆大霉素、利福平、复方新诺明、四环素及红霉素等有较强的耐药性。动物致病性试验结果表明,该菌对小鼠有强致病性。     

Relating tradable credits for biodiversity to sustainability criteria in a dynamic landscape

Tradable biodiversity credit systems provide flexible means to resolve conflicts between development and conservation land-use options for habitats occupied by threatened or endangered species. We describe an approach to incorporate the influence of habitat fragmentation into the conservation value of tradable credits. Habitat fragmentation decreases gene flow, increases rates of genetic drift and inbreeding, and increases probabilities of patch extinction. Importantly, tradable credit systems will change the level of fragmentation over time for small and/or declining populations. We apply landscape equivalency analysis (LEA), a generalizable, landscape-scale accounting system that assigns conservation value to habitat patches based on patch contributions to abundance and genetic variance at landscape scales. By evaluating habitat trades using two models that vary the relationship between dispersal behaviors and landscape patterns, we show that LEA provides a novel method for limiting access to habitat at the landscape-scale, recognizing that the appropriate amount of migration needed to supplement patch recruitment and to offset drift and inbreeding will vary as landscape pattern changes over time. We also found that decisions based on probabilities of persistence alone would ignore changes in migration, genetic drift, and patch extinction that result from habitat trades. The general principle of LEA is that habitat patches traded should make at least equivalent contributions to rates of recruitment and migration estimated at a landscape scale. Traditional approaches for assessing the “take” and “jeopardy” standards under the Endangered Species Act based on changes in abundance and probability of persistence may be inadequate to prevent trades that increase fragmentation.     

富平关中奶山羊临床型乳房炎病原菌的分离鉴定

为进一步探讨关中奶山羊乳房炎感染病原菌的情况,对富平县三个不同乡镇的79头患病奶山羊,共118份奶样进行分离鉴定,共分离出7种共126个菌株.其中大肠杆菌36株,占28.5%;金黄色葡萄球菌28株,占22.2%;绿脓杆菌23株,占18.3%;链球菌21株,占16.7%;变形杆菌8株,占6.3%;蜡样芽孢杆菌6株,占4.8%;酵母菌4株,占3.2%.认为该研究区域的关中奶山羊乳房炎主要是由大肠杆菌,金黄色葡萄球菌、绿脓杆菌、链球菌所致.     

Genetic diversity of apricot revealed by a set of SSR markers from linkage group G1

Eight polymorphic simple sequence repeat (SSR) markers located in the G1 linkage group of apricot (Prunus armeniaca L.) were previously developed and evaluated in a small set of cultivars. Those primers were used for studying variability in 77 apricot cultivars belonging to five different geographical groups, such as Chinese, Asian (Irano-Caucasian and Central Asian), North American, Mediterranean and Western European as well as Middle European cultivars. Six of the markers were polymorphic and revealed a total of 71 alleles ranging from 5 (aprigms11) to 20 (aprigms1) alleles per locus with a mean value of 11.83 alleles per locus. In conclusion, the SSR loci located in the G1 linkage group show a level of polymorphism which is similar to loci dispersed throughout the entire genome. The total number of alleles and the number of unique alleles were the highest in Chinese apricots and the lowest in Middle European cultivars. Heterozygosity also showed a decrease from Asia and China to Middle Europe. No association could have been observed between any SSR markers tested and plum pox virus (PPV) resistant phenotype of cultivars. PPV resistant cultivars did not form a separate clade on the dendrogram obtained by UPGMA cluster analysis. Middle European and Chinese cultivars formed separate clusters while other genotypes formed smaller multiple sub-groups or scattered among different clusters. Our results support previous hypotheses on the origin of PPV resistance in North American apricots. The allele data was also presented in a form that allowed the easy observation of allele frequencies in each geographical group at each locus. Using this data field, differences and similarities between cultivar groups can be easily assessed. The analysis demonstrated the links between the North American and Mediterranean apricot germplasm and confirmed that the Chinese and Eastern European cultivars are distantly related.     

恢复生态学的理论与研究进展

为了解西江流域广西境内卷口鱼 (Ptychidio jordani) 种群遗传结构及分化程度,采用线粒体Cytb基因序列对西江流域广西境内6个江段的139尾野生卷口鱼的遗传多样性进行了分析。结果显示,线粒体Cytb基因长度为1 053 bp,碱基T、C、A、G的平均含量分别为29.1%、27.7%、29.3%、13.9%,其中A+T (58.4%) 高于C+G (41.6%)。共定义20个单倍型,并聚为2个分支,未观察到明显的地理聚群。6个卷口鱼群体的平均单倍型多样性和平均核苷酸多样性分别为0.7682、0.0023,其中红水河群体 (单倍型多样性h=0.748 7,核苷酸多样性π=0.003 3) 遗传多样性最高,柳江群体 (h=0.274 4, π=0.000 4) 和左江群体 (h=0.3747, π=0.000 3) 的遗传多样性相对较低。卷口鱼总体的遗传分化指数 (F_ST) 为0.461 4 (P<0.01),表现出较大的遗传分化。两两群体间遗传分化结果显示,左江和柳江种群之间的遗传分化程度最大,而柳江和西江之间最小。AMOVA分析表明西江流域的卷口鱼群体遗传变异一半来自群体内 (53.86%),一半来自群体间 (46.14%)。中性检验 (Tajima's D=−1.082 8, P>0.05;Fu's Fs=−6.572 5, 0.01<P<0.05) 与碱基错配分布分析表明西江流域卷口鱼种群大约在0.07~0.187 Ma经历了种群扩张。综上,西江流域广西境内的卷口鱼柳江群体和左江群体遗传多样性较低,总群体分化程度较大,但仍属于一个种群,其中空间距离与地理阻隔对卷口鱼的遗传分化具有一定的促进作用。

     

应用聚合酶链式反应鉴定新疆棉花落叶型黄萎病菌

用一对棉花落叶型黄萎病菌的特异性引物D1和D2进行PCR扩增,对于落叶型黄萎病菌,该对引物可特异性地扩增产生一段550bp的产物,而非落叶型黄萎病菌则不能被扩增.供试的35个新疆黄萎菌系中,有3个菌系扩增出550bp大小的落叶型黄萎病菌特异性片段,表明目前新疆已存在落叶型黄萎病菌,用此技术可快速、准确地检疫和鉴定落叶型黄萎病菌.