Characterization of VP2 gene of an Indian Bluetongue virus serotype 2 and its close phylogenetic relationship to the Taiwan isolate

In this study we present the first report on partial amplification, sequencing and phylogenetic relationship of VP2 of the Indian isolate BTV-2. A PCR product of 1135 bp was amplified, cloned and sequenced. About 1063 bp of partial VP2 gene (1792-2854 bp region) of the Indian isolate was subjected to sequence analysis with already published sequences available in the genome database. The percent similarity of 85.2 was observed with Taiwan isolate and 59% with other isolates of BTV-2. However, 46.2% similarity with Australian BTV-1 and no significant similarity were noted with other serotypes. In-silico analysis and restriction enzyme digestion confirmed the presence of conserved SalI site at 2380 bp position in both Indian and Taiwan isolates. Phylogenetic analysis showed that all BTV-2 isolates formed one distinct group in which BTV-2 Indian and Taiwan isolate is more closely related and further demonstrated that BTV’s of the same serotype from different geographical regions were closely related at nucleotide and amino acid level, respectively.     

锦屏二级水电站减水河段生态环境资源价值核算研究

以自然资源补偿价值为依据,对雅砻江锦屏二级水电站减水河段的生态环境影响进行分析,发现其主要生态环境影响因子是水文环境的变化。该变化带来的不利影响将会导致减水河段鱼类资源生产损失。运用生产力变化法核算出主要因子的价值损失,结果表明,减水河段水环境变化导致的鱼类资源损失至少为80万~120万元/a。     

基于支持向量机的重叠大豆颗粒计数

为了提高大豆千粒重的测定效率和精度,提出一种基于机器视觉的有效分割多层重叠颗粒和记数方法.将由摄像机采集的大豆颗粒图像经预处理后,提取所有的颗粒块区域;寻找颗粒块区域的拓扑形状特征欧拉数和形状特征向量:颗粒块轮廓边缘上凹点、颗粒块类圆近似核心;采用支持向量机分类法智能识别颗粒叠加类型,将其分为串重叠、多个并粘连和两层并重叠,最后实现自动分割.结果表明:该方法能有效解决两层重叠或深度粘连类圆大豆颗粒的准确计数.     

Pinyon and Juniper Encroachment into Sagebrush Ecosystems Impacts Distribution and Survival of Greater Sage-Grouse

In sagebrush (Artemisia spp.) ecosystems, encroachment of pinyon (Pinus spp.) and juniper (Juniperus spp.; hereafter, “pinyon-juniper”) trees has increased dramatically since European settlement. Understanding the impacts of this encroachment on behavioral decisions, distributions, and population dynamics of greater sage-grouse (Centrocercus urophasianus) and other sagebrush obligate species could help benefit sagebrush ecosystem management actions. We employed a novel two-stage Bayesian model that linked avoidance across different levels of pinyon-juniper cover to sage-grouse survival. Our analysis relied on extensive telemetry data collected across 6 yr and seven subpopulations within the Bi-State Distinct Population Segment (DPS), on the border of Nevada and California. The first model stage indicated avoidance behavior for all canopy cover classes on average, but individual grouse exhibited a high degree of heterogeneity in avoidance behavior of the lowest cover class (e.g., scattered isolated trees). The second stage modeled survival as a function of estimated avoidance parameters and indicated increased survival rates for individuals that exhibited avoidance of the lowest cover class. A post hoc frailty analysis revealed the greatest increase in hazard (i.e., mortality risk) occurred in areas with scattered isolated trees consisting of relatively high primary plant productivity. Collectively, these results provide clear evidence that local sage-grouse distributions and demographic rates are influenced by pinyon-juniper, especially in habitats with higher primary productivity but relatively low and seemingly benign tree cover. Such areas may function as ecological traps that convey attractive resources but adversely affect population vital rates. To increase sage-grouse survival, our model predictions support reducing actual pinyon-juniper cover as low as 1.5%, which is lower than the published target of 4.0%. These results may represent effects of pinyon-juniper cover in areas with similar ecological conditions to those of the Bi-State DPS, where populations occur at relatively high elevations and pinyon-juniper is abundant and widespread.     

锥花福禄考根段的组织培养

以锥花福禄考根段为外植体,对影响其再生的主要因素激素和光照进行了试验,结果表明,每天光照12￣14h,在培养基MS 6-BA1.5mg/L NAA0.5mg/L可以直接获得再生植株,且诱导效果最好。     

利用CSSL群体研究稻米AC和PC相关QTL表达稳定性

利用以Asominori为遗传背景具IR24染色体片段的置换系（CSSL）群体，在“2年4点”8个环境对稻米直链淀粉含量（AC）和蛋白质含量（PC）进行QTL定位和表达稳定性分析。结果共检测到8个AC和PC相关QTL，其中2个QTL在8个环境中都能重复出现，即影响AC的qAC-8和控制PC的qPC-8，平均贡献率分别为21.0%和26.9%。qAC-8和qPC-8对应置换系与背景亲本Asominori在8个环境中相应性状的表现型都达到极显著差异(P<0.01)；都仅与8个环境中的2个环境之间存在显著的互作效应；说明qAC-8 和qPC-8的效应显著且稳定性较高。此外，qAC-8和qPC-8都被定位在第8染色体R727~G1149区间，IR24的等位基因可同时提高AC和PC，这为研究水稻籽粒直链淀粉和蛋白质形成途径之间的相互关系以及碳氮代谢协同调控的遗传机制提供了新的信息。     

锥花福禄考根段的组织培养

以锥花福禄考根段为外植体,对影响其再生的主要因素激素和光照进行了试验,结果表明,每天光照12￣14h,在培养基MS 6-BA1.5mg/L NAA0.5mg/L可以直接获得再生植株,且诱导效果最好。     

红茶加工过程中微生物卫生质量关键控制研究

红茶微生物卫生安全性问题是其出口的主要问题之一。为提高红茶卫生质量,根据它的生产工艺特点,随机抽取红茶生产中主要环节的茶样,分析其中细菌总数、大肠菌群最近似数、霉菌总数的污染情况,分析判定出红茶加工过程中卫生质量关键控制环节,提出红茶卫生质量改进措施。     

传染性法氏囊病病毒河南分离株（HN04）A片段cDNA的克隆及序列分析

利用RT-PCR技术,以传染性法氏囊病毒河南分离株(HN04)基因组RNA为模板,扩增并克隆IBDV HN04株基因组A片段cDNA。测序结果表明:克隆的A片段全长3260个核苷酸,包括2个部分重叠的开放阅读框(ORFl和ORF2)及两端的非编码区。ORFl和ORF2分别编码含有1012个氨基酸的结构蛋白(VP2-4-3)及含有145个氨基酸的VP5。IBDV HN04株基因组A片段核苷酸序列与来自GenBank IBDV血清Ⅰ型毒株核苷酸序列的同源性高达94.9%～99.4%,血清Ⅱ型毒株核苷酸序列同源性为83.8%。对IBDV HN04株的A片段核苷酸及其推导氨基酸进行序列分析,结果显示HN04株与国内外IBDV数株弱毒株的同源性在99.0%以上。