杜鹃花花色苷遗传变异的研究

采用高效液相色谱对7个杂交组合的父本、母本及其子代共27份杜鹃花样品进行分析,共检测到15种花色苷组分,其中,Cy3Ga、Cy3G和成分2、5、14为杜鹃花主要花色苷组分,累积含量占总花色苷的90％以上;而Dp3G花色苷仅在4份样品中出现.花色苷遗传变异模式的研究发现,Cy3G5G和成分15为增效基因占主导的多基因遗传控制模式,成分5、14和Cy3Ga为等效多基因遗传,成分2、4和Cy3G为减效基因占主导的多基因遗传控制模式,并以此推测类黄酮3-O-葡萄糖苷转移酶和类黄酮3-O-半乳糖苷转移酶基因的控制模式分别为减效基因占主导的多基因遗传模式和等效多基因遗传模式,而类黄酮5-O-葡萄糖苷转移酶基因为增效基因占主导的多基因遗传控制模式.花色比对结果显示,Dp花色苷与蓝紫花色呈现具有高度相关,成分14与洋红花色呈现具有密切关系,其余花色苷与大红花色呈现具有一定相关.最后初步探讨了杜鹃花花色的花色苷辅助育种策略.     

荔枝采后腐败褐变机理及保鲜技术研究进展

新鲜的荔枝（Litchi chinensis Sonn）果实营养丰富,经济价值高,但采后易褐变腐烂,不耐贮运,是荔枝远销和出口的瓶颈,阻碍了荔枝产业的发展。因此,荔枝采后生理特性研究及贮藏保鲜技术成为当前的研究热点。本文对当前荔枝腐烂褐变机理及保鲜技术的研究进展进行综述,并分析总结荔枝保鲜存在的问题,提出荔枝保鲜技术的研究方向。     

不同成熟度杨梅果实的品质及花青素组分比较

[目的]比较了不同成熟度杨梅果实的品质与花青素组分差异,为确定最佳采摘期提供依据.[方法]根据成熟度将杨梅果实分为转色期、粉果期、红果期和紫果期,测定感官品质和营养品质,并采用高效液相色谱法比较果肉花青素组分及含量.[结果](1)感官品质.粉果期杨梅果实纵径、横径与单果重最高,紫果期可食率和硬度最高.(2)营养品质.随...     

谷氨酰胺和L-肉碱对低温应激下AA肉仔鸡生产性能的影响

研究旨在从生产性能方面研究谷氨酰胺和L-肉碱在促进动物生长,减缓低温应激的影响,为生产实践应用抗应激添加剂提供理论依据和有益参考。采用L16(45)正交试验设计,将480只1日龄AA肉仔鸡,随机分为16组,每组3个重复,每个重复10羽肉仔鸡。谷氨酰胺添加水平分别为0%、0.4%、0.6%、0.8%,L-肉碱添加水平分别为0、50、75、100 mg.kg-1。预饲一周,试验期2周。低温条件下,在AA肉仔鸡基础日粮中联合添加谷氨酰胺和L-肉碱,显著提高了冷暴露AA肉仔鸡生产性能(p<0.05);谷氨酰胺为0.8%,L-肉碱的添加量为75 mg.kg-1对低温环境下肉仔鸡的作用效果最好。     

室内人工饲养橡副珠蜡蚧最适宜方法研究

对室内人工饲养橡副珠蜡蚧的适宜方法进行研究,结果表明,以海南本地秘本南瓜7成熟、绿色、长20～25 cm、直径8～9cm的南瓜为寄主,在采取水槽隔离保护、喷纯净水防止长霉、人工定期清理虫体分泌的蜜露等措施下,橡副珠蜡蚧可以更加快速有效地生长,为橡副珠蜡蚧的生物防治、化学防治等研究提供了大量虫源.     

行距播种量施肥灌水对新引1号东方山羊豆种子产量的影响

在新疆呼图壁县自然条件下,研究了播种量、行距和施肥灌水组合对新引1号东方山羊豆种子产量的影响.结果表明,播量和行距对新引1号东方山羊豆种子产量的影响显著,当播种量7.50kg/hm^2、行距60cm时种子产量最高,平均达211.46kg/hm^2;在此最适密度配置条件下进行施肥灌溉试验,得出的最佳水肥组合为：施厩肥30t/hm^2,尿素150kg/hm^2,二胺225kg/hm^2,灌溉6 000m3/hm^2.种子产量最高可达431.70 kg/hm^2,比未施肥前的产量比较差异极显著,增产效果明显.因此,从投入与产出比综合考虑,以收获种子为目的时新引1号东方山羊豆种子田适宜播种量7.50kg/hm^2、行距60cm,最佳水肥组合为施厩肥30t/hm^2,尿素150kg/hm^2,二胺225kg/hm^2,灌溉6 000m3/hm^2.     

Effects of different dietary protein levels and DL‐methionine supplementation on hair growth and pelt quality in mink (Neovision vision)

The effect of different dietary protein levels and DL‐methionine (Met) supplementation on hair growth and the resulting pelt quality in mink was studied. Four groups of male mink were fed with four isocaloric diets containing 32% (P32), 24% (P24), 16% (P16) or P24+Met (0.8%) crude protein of dry matter (DM) from September to December. Skin biopsies were taken at the pelting. Histological techniques and computer‐assisted light microscopy were used to determine the ratio of activity (ROA) of under hairs and guard hairs respectively. The results showed that when the dietary protein level reduced from 32% to 16%, body length, number and diameter of under hairs and guard hairs of minks declined, and pelt length and pelt weight of minks decreased significantly (p < 0.05). These parameters were similar between P32 and P24 with Met supplementation (p > 0.05). The hair follicle density of the winter coat was not influenced by the dietary protein levels and Met supplementation (p > 0.05). Low‐protein diets content led to a reduction of hair follicle developing to next phase. It was documented that 24% crude protein of DM with Met supplementation during growing‐furring period was sufficient for minks to express their genetic capacity to develop hair follicles and achieve the prime fur characteristics. Overall this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein and Met supply in the growing‐furring period of minks.     

饲粮精粗比和添加硫胺素对奶牛体外瘤胃发酵参数及菌群结构的影响

本试验采用体内逐渐提高奶牛饲粮精料水平与体外批次培养相结合的方法建立亚急性瘤胃酸中毒模型,旨在研究不同精粗比饲粮对硫胺素微生物净合成量的影响,以及添加硫胺素对亚急性瘤胃酸中毒状态下奶牛体外瘤胃发酵参数和菌群结构的影响。试验采用2×4因子完全随机试验设计,因素1为硫胺素添加水平,设0和180 mg/kg 2个水平,因素2为饲粮的精粗比,设4个水平,分别为40∶60、50∶50、60∶40、70∶30。试验共设8个处理,每个处理3个重复,于体外培养0、3、6、9、12 h后采集样品。结果表明:随着精料水平的提高,培养液中硫胺素的微生物净合成量呈先升高后降低的趋势,其中精粗比为40∶60、70∶30的饲粮组培养液中硫胺素的微生物净合成量在3、9、12 h时均显著或极显著低于精粗比为50∶50和60∶40的饲粮组(P<0.05或P<0.01)。在12 h时,随着精料水平的提高,培养液pH极显著降低(P<0.01),精粗比为70∶30的饲粮组发生亚急性瘤胃酸中毒;与未添加组相比,添加硫胺素组培养液pH极显著提高(P<0.01)。在6、9、12 h时,精粗比为60∶40和70∶30的饲粮组培养液中乳酸浓度极显著高于精粗比为40∶60的饲粮组(P<0.01);在3、9 h时,添加硫胺素可极显著降低培养液中乳酸浓度(P<0.01)。饲粮精粗比对培养液中溶纤维丁酸弧菌和反刍兽新月形单胞菌的数量无显著影响(P>0.05),但可显著或极显著影响培养液中牛链球菌、乳酸杆菌和埃氏巨型球菌的数量(P<0.05或P<0.01);与未添加组相比,添加硫胺素组培养液中牛链球菌的数量降低了3.84%(P<0.01),埃氏巨型球菌的数量提高了4.02%(P<0.01),但乳酸杆菌、溶纤维丁酸弧菌和反刍兽新月单胞菌的数量未发生显著变化(P>0.05)。由此得出,在高精料饲粮条件下,瘤胃中硫胺素的微生物净合成量降低,发生亚急性瘤胃酸中毒;添加硫胺素可通过提高瘤胃pH,降低乳酸浓度,以及调节瘤胃菌群结构来缓解亚急性瘤胃酸中毒。     

山西庞泉沟自然保护区河岸带鸟类群落组成与多样性研究

2005至2009年间,每年的4、5月和7、8月间对山西庞泉沟自然保护区河岸带的云杉林、针阔混交林、沙棘灌丛、柳树灌丛、河滩、农耕地、居民区等生境类型的鸟类群落结构进行调查,并观察记录河岸带鸟类的迁徙行为。调查共发现鸟类11目30科89种,其中,古北界51种(57.3%);东洋界12种(13.5%);广布种26种(29.2%);居留型分析显示,留鸟41种(46.1%),夏候鸟48种(53.9%);有国家一级重点保护动物3种,二级保护动物5种,省级保护动物7种,我国特产鸟类7种。本区候鸟的迁徙有一定的规律。对不同生境中鸟类群落间的多样性特征、物种间组成的复杂性进行计算和比较发现,不同生境存在显著差异,河岸带中针阔混交林生境中物种多样性指数较高。河岸带是庞泉沟保护区中的重要区域之一,在鸟类资源的保护过程中发挥着重要作用,建议进一步加强对河岸带鸟类群落的保护。     

Production of hydrogen peroxide and expression of ROS‐generating genes in peach flower petals in response to host and non‐host fungal pathogens

Reactive oxygen species (ROS) play dual roles in plant–microbe interactions in that they can either stimulate host resistance or enhance pathogen virulence. Innate resistance in peach (Prunus persica) to the brown rot fungal pathogen Monilinia fructicola is very limited, and knowledge of the mechanism of virulence is rudimentary. In this study, production of hydrogen peroxide, a major component of ROS, was determined in peach flower petals in response to M. fructicola (a host pathogen) and Penicillium digitatum (a non‐host pathogen). Monilinia fructicola was able to infect flower petals while P. digitatum was not. During the host‐specific interaction, M. fructicola induced hydrogen peroxide accumulation in flower petals. Application of exogenous antioxidants significantly reduced hydrogen peroxide accumulation as well as the incidence of brown rot disease. Application of M. fructicola spores to the surface of intact flower petals induced gene expression and increased enzyme activity of NADPH oxidase and cell wall peroxidase in host tissues, resulting in the production of hydrogen peroxide. Petals inoculated with M. fructicola exhibited high levels of protein carbonylation and lipid peroxidation. No significant response in gene expression, enzyme activity or hydrogen peroxide levels was observed in peach flower petals treated with P. digitatum. These results suggest that M. fructicola, as with other necrotrophic fungi, uses the strong oxidative response as part of a virulence mechanism.