蛋氨酸的生物学功能及其在鸡日粮中的应用

本文就蛋氨酸的生物学功能及其在鸡日粮中的应用作一综述。     

食用酒精DDGS对肉仔鸡生产性能、血液生化指标及胫骨质量的影响

分析食用酒精DDGS(玉米干酒糟及其可溶物)营养成分及毒素含量,研究此种DDGS对肉仔鸡生产性能、血清指标及骨骼质量的影响.试验选用240只1日龄科宝艾维菌48肉仔鸡,随机分成4组,每组6个重复.对照组饲喂基础日粮;1～21日龄阶段,试验Ⅰ、Ⅱ、Ⅲ组饲喂含有10％食用酒精DDGS日粮;22～35日龄和36～49日龄两个...     

Signatures of adaptation to obligate biotrophy in the Hyaloperonospora arabidopsidis genome

Many oomycete and fungal plant pathogens are obligate biotrophs, which extract nutrients only from living plant tissue and cannot grow apart from their hosts. Although these pathogens cause substantial crop losses, little is known about the molecular basis or evolution of obligate biotrophy. Here, we report the genome sequence of the oomycete Hyaloperonospora arabidopsidis (Hpa), an obligate biotroph and natural pathogen of Arabidopsis thaliana. In comparison with genomes of related, hemibiotrophic Phytophthora species, the Hpa genome exhibits dramatic reductions in genes encoding (i) RXLR effectors and other secreted pathogenicity proteins, (ii) enzymes for assimilation of inorganic nitrogen and sulfur, and (iii) proteins associated with zoospore formation and motility. These attributes comprise a genomic signature of evolution toward obligate biotrophy.     

Intersubgeneric cross in Nymphaea spp. L. to develop a blue hardy waterlily

Five waterlily cultivars, with good pod setting and completely formed flowers, from the subgenus Nymphaea (hardy waterlily) were used as pod (female) parent. Waterlilies from subgenera Anecphya (2 entities) and Brachyceras (20 entities), specifically the blue-flowered ones, were used as pollen (male) parent for transferring blue-flowered characteristic to the hardy waterlily. Hybridization of subgenus Nymphaea with subgenus Anecphya was unsuccessful. A successful crossing was obtained between the subgenera Nymphaea and Brachyceras, yielding one pod with 244 seeds, from which only 39 seeds germinated and yielded 20 good intersubgeneric hybrid plants. The characteristics of the hybrids were categorized by their flower colors into two groups, a pink-flowered group with 17 hybrids and a blue-flowered group with 3 hybrids. In the blue-flowered group, there was a prominent one with beautiful blue-purple flower, which was determined by PCR-RFLP markers to be a hybrid between Nymphaea and Brachyceras subgenera, as well as inherited some plant characteristics, for example, ovary carpel, leaf (pad), rootstock, position of flower at flowering from the parent. The blue-purple flowered hybrid had important characteristics inherited from the hardy waterlily (subgenus Nymphaea); therefore, the hybrid has been named Nymphaea ‘Siam Blue Hardy’ to honor the birth place and its distinct flower color.     

与大豆田间老化抗性连锁的分子标记的发掘及辅助选择应用研究

大豆种子成熟至收获期间如遇高温高湿天气,种子活力及活性会急剧下降,这就是所谓的田间老化(field weathering).田间老化是热带、亚热带地区大豆生产的主要限制因素之一.本研究旨在寻找与田间老化性状相连锁的DNA标记并将其应用于辅助选择育种.为此,利用修改的培养箱老化法和人工控制老化法对大豆品种Chiangmai 60(敏感),GC10981(抵抗)及其F2群体(139个体)进行了鉴定.在两种处理条件下,F2代群体的种子发芽率及活性均为正态分布,说明大豆种子田间老化抗性受多个基因控制.根据F2代个体的种子发芽率及活性,6个高抗个体及7个高感个体的DNA分别被混合为抗性池和感性池,并利用AFLP标记进行了混合群体分析(Bulk Segregant Analysis).从扩增的2162个标记中,发现了5个可能于大豆种子田间抗性相连锁的片段.通过DNA克隆和测序,设计了5对引物用于从大豆总DNA中扩增相应的片段.其中3对引物扩增的片段差异太小或未能扩增正确大小的片段,没能用于F2群体.引物Eaag/Mcac-233和Eact/Mctt-157能扩增出差异明显的多态性,通过对F2代群体的分析,这2个标记属同一连锁群,遗传距离为25.8cM.QTL分析结果显示有一个QTL位于这两个标记之间,距Eaag/Meac-233约14cM,可以解释29.7%的变异.用这两对引物对整个F2群体进行筛选,20个个体属于抗性群体,结合抗性鉴定的结果,7个个体被用于与Chiangmai 60进行回交.18个BC1F1个体(41.9%)的抗性高于其亲本的平均值.说明这些标记进行可以被用于大豆田间老化抗性的辅助筛选研究.     

Reliable enzyme-linked immunosorbent assay for the determination of coconut milk proteins in processed foods

This study was designed to develop a novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of coconut milk proteins in processed foods. The developed sandwich ELISA was able to detect coconut milk proteins from various coconut milk products and did not show any cross-reactivity with 41 of 42 kinds of popularly used food ingredients, thus reflecting great specificity for coconut milk proteins. In addition, the established ELISA is highly sensitive and allowed the detection of 0.31 μg/g of coconut milk protein in complex food matrices. This proposed assay could serve as a useful tool for the detection of the presence of hidden coconut milk proteins in processed foods.