南美叶疫病菌适生因子及地理分布

南美叶疫病是橡胶树的一种毁灭性病害。依据已有的研究,本文综述了南美叶疫病菌的适生因子、地理起源、传播历史、地理分布以及适生因子与该菌地理分布的关系,旨在为该菌的风险分析提供依据。     

两种除草剂对紫背浮萍的生长抑制活性研究

本文以叶状体数为测试指标,在实验室条件下研究了除草剂草甘膦、二甲戊灵对紫背浮萍生长的影响。结果表明:在一定范围内,两种除草剂均对紫背浮萍的生长具有明显的抑制作用,抑制率都随浓度的增加而增大,处理168h后,草甘膦、二甲戊灵对紫背浮萍叶状体的EC50分别为12.817、0.483mg/L。     

Effects of dietary lysozyme levels on growth performance,intestinal morphology,non‐specific immunity and mRNA expression in weanling piglets

The aim of the present study was to determine the effect of dietary lysozyme levels on growth performance, gut health and non‐specific immunity of weanling piglets. A total of 150 weanling piglets were allocated to six treatments. The piglets were fed the same basel diet supplemented with 0, 30, 60, 90 and 120 mg/kg lysozyme as well as antibiotics for 28 days. From day 14 to day 28 of dietary treatment, piglets fed 90 mg/kg lysozyme had greater average daily gain than piglets fed control diet. During the whole experimental period, piglets fed 120 mg/kg lysozyme tended to have greater average daily gain than piglets fed control diet. Compared with piglets fed control diet, piglets fed diets containing antibiotics and 90 mg/kg lysozyme had greater villus height to crypt depth ratio in duodenum and jejunum. Additionally, dietary supplementation of 60 and 90 mg/kg lysozyme as well as antibiotics enhanced the phagocytic activity of peritoneal macrophages in piglets. In conclusion, dietary lysozyme can accelerate the growth of weanling piglets by improving gut health and non‐specific immunity and supplementing 90 mg/kg lysozyme is as effective as antibiotics (20 mg/kg colistin sulphate + 50 mg/kg kitasamycin) in improving the growth performance of weanling piglets.     

多不饱和脂肪酸与免疫的关系

许多营养素如维生素、微量元素、某些氨基酸和多不饱和脂肪酸等都可以影响动物机体的免疫反应。脂肪酸是一种重要的营养素,是机体能量的主要来源,发挥着重     

胶孢炭疽菌T-DNA插入突变体库的构建及其分子分析

利用根癌农杆菌介导的T-DNA插入遗传转化体系转化杞果炭疽菌SC2菌株,共获得抗潮霉素B突变体4 680个,平均每转化1.0×106个炭疽菌分生孢子可得到300～980个突变体,且潮霉素抗性在多次传代实验中得到稳定遗传.随机挑取38个突变体进行PCR检测,均可扩增出1条约1.2 kb的目标谱带,说明突变体为T-DNA插入引起:进一步的Southern blot杂交分析结果表明,在随机挑选的20个突变体中,有1个(5%)为三拷贝T-DNA插入,4个(20%)为双拷贝插入,剩余的15个(75%)为单拷贝插入.     

Effects of melatonin on maturation,histone acetylation,autophagy of porcine oocytes and subsequent embryonic development

Melatonin (MLT) is an endogenous hormone with roles in animal germ cell development. However, the effect of MLT on porcine oocyte maturation and its underlying mechanisms remain largely unknown. Here, we investigated the effects of exogenous MLT on oocyte maturation, histone acetylation, autophagy and subsequent embryonic development. We found that 1 nmol/L MLT supplemented in maturation medium was the optimal concentration to promote porcine oocyte maturation and subsequent developmental competence and quality of parthenogenetic embryos. Interestingly, the beneficial effects of 1 nmol/L MLT treatment on porcine oocyte maturation and embryo development were mainly attributed to the first half period of in vitro maturation. Simultaneously, MLT treatment could also improve maturation of small follicle‐derived oocytes, morphologically poor (cumulus cell layer ≤1) and even artificially denuded oocytes and their subsequent embryo development. Furthermore, MLT treatment not only could decrease the levels of H3K27ac and H4K16ac in metaphase II (MII) oocytes, but also could increase the expression abundances of genes associated with cumulus cell expansion, meiotic maturation, histone acetylation and autophagy in cumulus cells or MII oocytes. These results indicate that MLT treatment can facilitate porcine oocyte maturation and subsequent embryonic development probably, through improvements in histone acetylation and autophagy in oocytes.     

华南虎皮肤成纤维细胞的分离培养

应用酶消化法（胶原酶消化：0.1%胶原酶Ⅰ型＋0.1%BSA;胰蛋白酶消化：0.25%胰蛋白酶＋1mM EDTA）和植块法从华南虎皮肤组织中分离成纤维细胞。研究结果表明,植块法较适合分离华南虎皮肤成纤维细胞,胶原酶消化法次之,而胰蛋白酶消化法不宜用于分离华南虎皮肤成纤维细胞。DMEM/F12（1：1）培养基＋10%FCS＋10 ng/ml EGF＋5μg/ml胰岛素＋100 IU/ml青霉素＋100μg/ml链霉素组成的培养体系适用于华南虎皮肤成纤维细胞的体外培养。     

水稻雄性不育突变体012S-3的遗传分析和基因定位

雄性不育是水稻杂种优势利用的重要资源,对雄性不育现象的研究具有重要理论意义和实践价值。本研究以自然突变的水稻雄性不育突变体012S-3为试验材料,对其表型特征和花粉育性等进行调查,并构建遗传群体,利用分子标记对目的基因进行初步定位,然后应用基因组重测序技术对其进行精细定位。结果表明,012S-3是一个典型的无花粉普通型雄性不育材料,其不育性状受1对隐性核基因控制。初步定位分析目的基因与SSR标记RM6081存在连锁关系,其遗传距离约为34.4 c M;进一步的精细定位分析,找到3个候选基因:LOC_Os07g35880、LOC_Os07g35920和LOC_Os07g35940,其中LOC_Os07g35880和LOC_Os07g35940编码β-淀粉酶,属于水稻中新发现的花粉致死基因。该不育基因的成功定位为其进一步的分离克隆及其在水稻分子设计育种中的应用奠定了基础。     

半番鸭适宜日粮营养水平的研究

在相同饲养管理条件下，三组半番鸭分别饲喂不同营养水平的日粮，观察各组肉鸭的增重、成活率、饲料报酬、屠体品质等性状。结果表明：4～7周龄日粮适宜蛋能比为14．41克／兆焦、粗蛋白17％、8～9周龄12．08克／兆焦、粗蛋白14．5％。     

广西芒果日灼病受害情况调查及防治措施

为了掌握2012年广西南宁和百色地区芒果日灼病的发生受害情况,于4月29日、5月2日、5月8-11日和5月15-18日在南宁市、百色市右江区、田林县、田东县和西林县选择有代表性的果园,调查不同芒果品种幼果日灼病的受害率.调查结果表明:(1)南宁地区未发现果实受日灼病危害;右江河谷地区日灼病发生较为普遍,田东县、田林县、西林县、右江区和广西农垦国有阳圩农场的芒果日灼病受害率分别为22.2％ 、20.3％、22.8％、19.6％和20.4％.(2)不同品种受害率不同.‘台农1号芒,受害率最低,为12.0％;‘红贵妃’、‘桂热芒82号’和‘桂热芒71号’受害率较高,分别达到31.3％、29,6％和27.5％.针对春末夏初芒果幼果易遭高温日灼的问题,提出了果园灌水、生草、播种绿肥等降低日灼病发生的预防措施.