野燕麦对精噁唑禾草灵、炔草酯敏感性差异测定

为明确不同野燕麦种群对精噁唑禾草灵和炔草酯的敏感性水平,采用整株生物测定与种子生物测定分别检测了河南、湖北、江苏三省共11个野燕麦种群对精噁唑禾草灵和炔草酯的敏感性。结果表明,2种测定方法获得的野燕麦种群对2种除草剂的敏感性基本一致。整株生物测定结果显示,不同野燕麦种群对精噁唑禾草灵和炔草酸的敏感性存在显著差异,其中,金水闸野燕麦种群对精噁唑禾草灵和炔草酯敏感性最高,其GR50值（有效成分）分别为2.46、3.65 g/hm2,而辉县野燕麦种群对精噁唑禾草灵和炔草酯敏感性最低,GR50值（有效成分）分别为15.00、23.12 g/hm2,其余野燕麦种群对精噁唑禾草灵和炔草酯的敏感性介于金水闸种群与辉县种群之间。种子生物测定结果与整株生物测定结果趋势一致,但表现出的敏感性略高。     

对甜菜夜蛾高毒力Bt新菌株的PCR-RFLP分析及生物活性测定

利用PCR-RFLP对Bt.新菌株cyz-13,T4-3的基因型进行分析。结果表明,cyz-13含有cry1Aa,cry1Ac,cry1Bc,cry2Ab4种基因型,其中cyz-13菌株的PCR产物的酶切片断类型不同于已知的基因类型;T4-3菌株含有cry1Aa,cry1Ac,cry1Ag,cry2Ac,cry1Ia5种基因型。室内生测结果显示,两菌株对甜菜夜蛾、粘虫、棉铃虫、玉米螟均具有高毒力,好于H D-1标准菌株。两菌株的发酵液均有杀虫活性,二者上清的杀虫因子不同。     

斑蝥素微乳剂优化配方(25号)毒力测定

采用菜蛾(Plutella xylostellaL.)三龄幼虫为试虫对自行研制的生物源农药杀虫剂斑蝥素微乳剂优化配方(25号)的杀虫活性进行了室内毒力测定。结果表明:试虫中毒后主要表现为活动能力下降至逐渐死亡,且虫体前中部发黑。该优化配方对试虫的胃毒致死中浓度LC50,触杀致死中浓度LC’50,选择性拒食中浓度AFC50,非选择性拒食中浓度NAFC50分别为0.80±0.02,0.85±0.05,1.80±0.12和1.26±0.04 mg.L-1;与阿维菌素丙酮溶液(CK1)相比,该配方对试虫的触杀作用高出57.5%,选择性拒食作用高出59.5%;综合评估指数(EI)高出38.5%;与斑蝥素丙酮溶液(CK2)相比,该配方对试虫的胃毒作用、触杀作用、选择性拒食作用、非选择性拒食作用、综合评估指数(EI)分别提高44.4%,62.6%,61.9%,86.6%和73.6%,差异均达显著水平(P≤0.05)。     

Molecular mapping of a stripe rust resistance gene in Chinese wheat cultivar Mianmai 41

Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), is one of the most damaging diseases of wheat. Chinese wheat cultivar Mianmai 41 showed high resistance against most of the prevailing Pst races in China. Genetic analysis of the F1, F2 and F2:3 populations from a cross between Mianmai 41 and a susceptible line Mingxian 169 indicated that resistance to Pst race CYR32 was conferred by a single dominant gene, temporarily designated as Yr MY41. Molecular marker analysis placed the gene on chromosome 1B near the centromere. Six co-dominant genomic SSR markers Xwmc329, Xwmc406, Xgwm18, Xgwm131, Xgwm413, and Xbarc312, and one STS marker Xwe173 linked with the resistance gene. The two closest flanking SSR markers were Xgwm18 and Xwmc406, with genetic distances of 2.0 and 4.9 c M, respectively. A seedling test with 29 Pst isolates indicated the reaction patterns of Mianmai 41 were different from those of lines carrying Yr3, Yr9, Yr10, Yr15, Yr26, and Yr CH42 on chromosome 1B. Allelic tests indicated that Yr MY41 is likely a new allele at Yr26 locus.     

水稻机插露天简易操作育秧技术

水稻机插简易操作育秧技术是一项操作简单,农民容易接受的一种育秧技术。2012-2014年浦城县引进机插秧简易操作育秧技术,效果很好,可节约成本480元/667m2。介绍了浦城县水稻机插露天简易操作育秧技术。     

A comparison of three earthworm bioassay procedures for the assessment of environmental samples containing hazardous wastes

Summary Three different laboratory earthworm protocols for assessing the potential toxicity of environmental samples were evaluated using Eisenia fetida. The 48-h Contact Test (CT) is a short test and may indicate the presence of water-soluble chemicals. The 14-day Soil Test (ST) is best suited to assess chemical impacts of either known or unknown chemicals in soils. The Giant Axon Conduction Velocity protocol (GACVT) used with either the CT or the ST can detect sublethal neurotoxic effects in shorter periods of time and at lower chemical concentrations than mortality tests. The use of these tests is suggested as an estimate of potential toxicity of environmental soil samples.