黄土低山丘陵及坨甸草原区风蚀规律的研究

本文通过对黄土低山丘陵及坨甸草原区248个风蚀图斑资料的分析,运用线性模型理论,对此地区的风蚀规律进行了研究。获得了下垫面各因素与风蚀量关系的数学模型。找出了影响风蚀的主导因素,并系统阐述了植被覆盖度和土地利用类型对风蚀量大小的影响,且与水蚀规律进行了比较分析。     

Organic substance metabolism during seed germination ofPinus bungeana

The metabolism of fats, proteins and carbohydrates and change of enzyme of seeds ofpinus bungeana during the germination were conducted by the methods of gas-liquid chromatography, flow injection, colorimetric analysis of spectrophotometer, to provide theoretical basis for seeds dormancy, germination and storage of seeds of forest tree. The results indicate that (1) carbohydrates were first utilized during germination of seed ofpinus bungeana; (2) stored substances in seeds began to decompose quickly after radicale broke through seed coats; (3) the activity of enzymes in the seeds does not always coincides with the increase or decrease in quantity of its responsible substance during germination of the seed. Changes in stored substance relate to metabalism of other metabolism of other materials and the use of hydrolysates.     

蛋鸡血浆VLDL浓度二世代双向选择对体脂沉积的影响

以雅发褐壳蛋鸡为素材,在零世代和一世代双向选择的基础上,应用血浆极低密度脂蛋白(VLDL)浓度对体腹脂性状继续进行双向选择,比较了高低脂系间体组成的差异,并研究了中后期血浆VLDL浓度与上述性状的相关程度,进一步探讨了血浆VLDL浓度的选择效应。结果表明:二世代母鸡中后期高脂系体重较高(P<0.05),血浆VLDL浓度与体重呈极显著的表型相关(P<0.01)和中等程度的正遗传相关。62周龄高脂系的腹脂率显著高于低脂系(P<0.05),说明运用血浆VLDL浓度经过二个世代的双向选择,使产蛋鸡中后期体重降低,且对腹脂沉积产生了一定的影响。     

化学法和生物法制备巨菌草腐植酸的比较

对化学方法和生物方法制备巨菌草(Pennisetum sp.)腐植酸和黄腐酸进行分析比较。结果表明,硝酸、盐酸、乙酸、草酸、氨水均能降解纤维素、半纤维素或木质素从而生产腐植酸和黄腐酸,其中10.0%氨水提取巨菌草得到的腐植酸含量最高,其次为37.5%硝酸和37.5%盐酸,草酸和乙酸提取得到的腐植酸含量最低。枯草芽孢杆菌(Bacillus subtilis)、毛霉(Mucor)、根霉(Rhizopus)、青霉(Penicillium)在巨菌草腐殖质的形成中均起到了积极作用,其中根霉对木质素的降解程度最高,生成总腐植酸的含量最高。根霉发酵制备得到的总腐植酸含量是10.0%氨水提取得到的总腐植酸含量的1.45倍,毛霉发酵制备得到的总腐植酸含量是10.0%氨水提取得到的总腐植酸含量的1.29倍,而枯草芽孢杆菌和青霉发酵制备得到的总腐植酸含量比10%氨水提取得到的总腐植酸含量低。37.5%硝酸提取得到的黄腐酸含量是毛霉发酵制备得到的黄腐酸含量的1.79倍,22.5%盐酸提取得到的黄腐酸含量是毛霉发酵制备得到的黄腐酸含量的1.98倍。综上可知,生物发酵法制备得到的总腐植酸含量比化学法提取得到的总腐植酸含量要高,而化学方法提取得到的黄腐酸含量比生物发酵法制备得到的黄腐酸含量要高。     

Saquayamycin B1 Suppresses Proliferation,Invasion, and Migration by Inhibiting PI3K/AKT Signaling Pathway in Human Colorectal Cancer Cells

Moromycin B (Mor B), saquayamycin B₁ (Saq B₁), saquayamycin B (Saq B), and landomycin N (Lan N), four angucyclines produced by the marine-derived actinomycete Streptomyces sp., are a class of polyketone compounds containing benzanthracene. Here, the structure–activity relationship of these four compounds was analyzed in human colorectal cancer (CRC) cells. Saq B₁, which showed the strongest cytotoxicity with an IC₅₀ of 0.18–0.84 µM for CRC cells in MTT assays, was employed to test underlying mechanisms of action in SW480 and SW620 cells (two invasive CRC cell lines). Our results showed that Saq B₁ inhibited CRC cell proliferation in a dose- and time-dependent manner. Notably, lower cytotoxicity was measured in normal human hepatocyte cells (QSG-7701). Furthermore, we observed proapoptosis, antimigration, and anti-invasion activities of Saq B₁ in CRC cells. At the same time, the protein and mRNA expression of important markers related to the epithelial–mesenchymal transition (EMT) and apoptosis changed, including N-cadherin, E-cadherin, and Bcl-2, in Saq B₁-treated CRC cells. Surprisingly, the PI3K/AKT signaling pathway was shown to be involved in Saq B₁-induced apoptosis, and in inhibiting invasion and migration. Computer docking models also suggested that Saq B₁ might bind to PI3Kα. Collectively, these results indicate that Saq B₁ effectively inhibited growth and decreased the motor ability of CRC cells by regulating the PI3K/AKT signaling pathway, which provides more possibilities for the development of drugs in the treatment of CRC.     

辣椒雄性不育的研究进展

综述了辣椒雄性不育的遗传类型,不育基因的来源、分布及其特性和不育植株在形态、细胞学和生理指标上的表现,并且分析了辣椒雄性不育在生产中的应用,提出了尚存在的问题.     

9种常用杀螨剂对巴氏新小绥螨和二斑叶螨的毒力及毒力选择性研究

为使化学防治和保护利用捕食螨的生物防治措施相协调, 实现以螨治螨, 采用叶片残毒法分别测定了甘肃省保护地常用的9种杀螨剂对巴氏新小绥螨和二斑叶螨的LC50, 计算出各药剂的益害生物毒性选择指数(TSR)。供试药剂的毒性选择指数大小依次为：毒死蜱＞螺螨酯＞哒螨灵＞炔螨特＞唑螨酯＞阿维菌素＞三唑锡＞甲氰菊酯＞噻螨酮。其中, 毒死蜱和螺螨酯的毒性选择指数分别为10.864 1和9.361 3, 对巴氏新小绥螨和二斑叶螨均有较高的正向选择性, 毒死蜱和螺螨酯可优先用于生产中害虫(螨)的防治, 同时最大限度地保护了捕食螨, 实现对害虫(螨)化学防治和生物防治的相互协调。     

桔小实蝇在不同杨梅品种上的生长发育特性研究

本文选择了浙江3种不同杨梅品种,研究了桔小实蝇取食后的生长发育相关5种性状的差异,结果表明,幼虫历期以荸荠种最短,蛹历期和蛹重,水梅值最小;雄成虫东魁最重,并均与另2个杨梅品种差异达显著水平。而幼虫,幼虫-蛹,幼虫-成虫3种存活率,荸荠种最高,水梅最低,二者差异也达显著水平。显然桔小实蝇对不同杨梅品种喜好有所不同,其较为喜好荸荠种,较不喜好水梅。结合果实性状考查结果,不喜好的原因可能与水梅偏酸有关。但上述3品种上桔小实蝇生长发育性状与其嗜好寄主香蕉极为     

大娄山区巴山榧树遗传多样性的RAPD分析

利用RAPD技术对大娄山地区3个居群29个巴山榧树个体进行了遗传多样性分析.结果表明:12个10bp寡核苷酸引物共检测到81个位点,其中多态性位点61个.在物种水平上,大娄山区巴山榧树的多态性位点百分率为75.31%,Nei's基因多样性指数为0.2437,Shannon's信息指数为0.3703;而在居群水平上,遗传...     

贵州野生匍匐剪股颖POD等位酶位点遗传变异分析

试验旨在揭示材料间的亲缘关系,从而为促进中国野生草坪草种质资源的收集、保存、以及核心种质资源的构建等具有重要意义,同时也为品种选育过程中亲本选配、后代遗传变异程度及杂种优势水平的预测提供预见性的指导。试验以国外匍匐剪股颖品种KROMI为对照,对贵州三大地区的18份野生匍匐剪股颖材料POD等位酶住点遗传变异进行分析,共检测到两个POD等住酶位点Pod-1、Pod-2。其中Pod-1有八条酶带,迁移率（RF）分别为0．031、0．046、0．065、0．088、0．111、0．131、0．163、0．183;Pod-2有四条酶带,迁移率（RF）分别为0．644、0．667、0．699、0．752;根据POD等位酶基因型分析结果,Pod-1位点等位酶四级结构为二聚体,Pod-2酶位点为单聚体。Pod-1位点合Pod-1a、Pod-1b、Pod-1c、Pod-1d四个等位基因,其中Pod-1a、Pod-1b、Pod-1c在材料中出现频率最高,为主导基因;Pod-2位点合Pod-2a、Pod-2b、Pod-2c、Pod-2d四个等位基因,其中Pod-2c出现频率最高,为Pod-2住点主导基因。根据试验结果,可将供试材料分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四大类。