Ecologie des champignons parasites dans le sol—IX. Mesures du potentiel infectieux des sols naturellement infestes de Pythium SP

The technique of estimating inoculum potential of soils infested by Pythium (Bouhot 1975a,b,c) has been applied to more than 600 soil samples. 24 examples of soils, representing the several kinds of results, are presented. In order to improve the linearity of the inoculum density-disease regression, the four mathematical transformations of disease percentages, proposed by Baker (1971), are compared: logarithm of disease percentages, successful infection transformation (LN I/I — ×), log-log and Probit-log. For 80–90% of observed soils the log-log and Probit-log transformations give a straight regression line and allow the differentiation of soils by the use of UPI₅₀ (LD 50 point). The Probit-log appears to be the best to reduce the variance of replications. On the contrary for some soils the inoculum-disease relation is a concave curve different from the ideal curve proposed by Baker. The hypothesis of competition between saprophytic colonization of Pythium and of soil microflora is proposed as an explanation and suggests the opportunity to find a new model for the techniques using plants as bait and organic amendment.     

与DNA硫修饰相关的DndB 蛋白纯化体系的建立

根据DndB蛋白表达载体的特性,建立了一套集Ni2+-NTA亲和层析、Source Q阴离子交换层析和Superdex 200分子筛层析于一体的纯化体系,纯化得到高纯度的DndB蛋白,可用于后续的蛋白质结构生物学和酶学特性研究,为阐明DndB蛋白的功能以及DNA硫修饰的机理打下了良好的基础.     

基于TD 200的低成本PLC网络监控系统

基于TD 200的PLC的PPI网络监控系统，可作为一种低成本小型控制系统的开发模式．通过对木材干燥窑的模拟实验，详细叙述了其组成和特点．     

卫福200FF种衣剂防治甜玉米苗期病害的效果

为了明确卫福200FF种衣剂对甜玉米苗期病害的防治效果和安全性。田间试验设卫福200FF种衣剂 200、250、300ml∕100kg种子,对照药剂50%福美双WP 500g/100kg种子及空白对照5个处理。结果用该制剂200ml～300ml/100kg拌种,防治效果达76.94%～82.12%,增产11.91%～14.93%,且未见玉米苗出现药害现象。试验表明卫福200FF种衣剂对甜玉米苗期病害有较好的防病增产作用和安全性,可作为防治甜玉米苗期病害的药剂在生产上推广应用。     

Effects of non-antibiotic feed additives on performance, tibial dyschondroplasia incidence and tibia characteristics of broilers fed low-calcium diets

This experiment was conducted to investigate and compare the efficacy of different feed additives on performance, tibial dyschondroplasia (TD) incidence and tibia characteristics of male broilers fed low-calcium diets. A completely randomized design, with six treatments and five replicates of five chicks per each was used. Experimental treatments were: (i) Basal diet containing recommended level of calcium (0.9%) as control treatment (Ctrl), (ii) low-calcium (0.67%) diet without any additive (LC), (iii) low-calcium diet + probiotic (2 g/kg diet), (iv) low-calcium diet + prebiotic (2 g/kg diet), (v) low-calcium diet + synbiotic [mix of probiotic and prebiotic (each 2 g/kg diet)], (vi) low-calcium diet + organic acid (1.5 g/kg diet). Birds were reared in an open-sided house system under natural tropical condition until 21 days of age. Feeding with low-calcium diet negatively influenced broiler performance (body weight, body weight gain and feed conversion ratio) and tibia characteristics, whereas dietary inclusion of all feed additives had beneficial effects on above-mentioned parameters and helped the birds to overcome problems related to low-calcium diets. Different treatments had no effect on TD incidence.     

抗青枯病花生新品种粤油200的选育研究

:粤油 2 0 0是广东省农科院作物研究所用 (粤油 1 87×粤油 92 ) F1 为母本 ,(粤油 3 2 0 -2 6×粤油 92 ) F1 为父本通过复合杂交选育而成。 1 988～ 1 990年全国南方片花生品种区域试验 (抗病组 )平均产量 3 0 84 .1 5kg/ hm2 ,比 CK1 粤油 92增产 1 7.3 2 %,比 CK2 粤油 1 1 6增产 4 7.2 6%。在人工接种试验中 ,青枯病发病率为6.6%。     

Comparative pharmacokinetics of baicalin in normal and the type 2 diabetic rats after oral administration of the Radix scutellariae extract

Radix scutellariae was used alone or in combination with other medicinal herbs in the treatment of type 2 diabetes mellitus in China. At present, the pharmacokinetics of baicalin in type 2 diabetic rats following oral administration of Radix scutellariae extract was investigated. The results showed that the pharmacokinetics (especially AUC) of baicalin in type 2 diabetic rats after oral administration of Radix scutellariae extract was remarkably different from that in normal rats. Then the mechanism which resulted in the increased AUC of baicalin in diabetic rats was investigated from system clearance and presystemic metabolism. And it was found that the increased AUC of baicalin in diabetic rats at least partly resulted from higher production of baicalein in the intestinal tract of type 2 diabetic rats. Moreover, the activity of β-glucuronidase in intestinal mucosa of type 2 diabetic rats was demonstrated to be higher than that in normal rats, which confirmed the results above. In conclusion, the pharmacokinetic behavior of baicalin was significantly altered in type 2 diabetic rats after orally administrated Radix scutellariae extract, which may partly result from the increased activity of intestinal β-glucuronidase under the pathological state of type 2 diabetes mellitus.