Laboratory evaluation of phytosanitary products used for control of the South American fruit fly, Anastrepha fraterculus, in organic farming

The South American fruit fly, Anastrepha fraterculus (Wied.), is one of the principal pests of fruit crops in Brazil. While organic farms use several compounds to control fruit flies, such as oils, plant extracts and soaps, there is little scientific evidence of their effectiveness. Our main goal was to evaluate the phytosanitary products used in organic orchards on A. fraterculus under laboratory conditions. Four multiples (0.25×, 0.5×, 1× and 2×) of the manufacturer-recommended concentrations of Rotenat CE^® (extract of Derris spp. with rotenone 5%) (600 ml 100 l⁻¹), Pironat^® (pyroligneous extract) (250 ml 100 l⁻¹), Biopirol 7M^® (pyroligneous extract) (200 ml 100 l⁻¹), Organic neem^® (neem oil 80%) (500 ml 100 l⁻¹), Natuneem^® (neem oil - 1500 ppm of azadirachtin) (500 ml 100 l⁻¹) and lime sulfur (20% S + 9% Ca) (5000 ml 100 l⁻¹) were tested on A. fraterculus via ingestion and direct contact, topical application and residual application. We subsequently tested deterrence effects of the same products on oviposition. Organic Neem^®, Natuneem^®, lime sulfur, Pironat^®, and Biopirol 7M^® showed no insecticidal effect on the South American fruit fly. Only Rotenat CE^® (1200 ml 100 l⁻¹) showed an effect (71.6% mortality) following ingestion/contact. Lime sulfur, Pironat^® and Biopirol 7M^® did not prevent oviposition of A. fraterculus on artificial fruits.     

植物性杀虫剂印楝的研究进展

对植物性杀虫剂印楝的研究正在向两个方向发展, 一是深入到分子毒理水平, 进行结构与活性关系的研究; 另一方面是研究其在害虫防治中的应用。文章就目前印楝制剂的使用技术研究状况作了评述。由于植物性杀虫剂在作用方式和作用机制上与有机合成杀虫剂有一定的差别, 对害虫的作用靶标有所不同, 因此, 在剂型和药剂分散体系的设计上也有所不同,对这些相关领域进行深入研究, 将能更有效地发挥包括印楝在内的植物性杀虫剂在田间的使用效果, 是植物性杀虫剂研究中一个非常重要的内容。     

印楝素杀虫剂防治甜菜甘蓝夜蛾效果初探

试验结果表明,喷施0.3%绿晶印楝素杀虫剂防治甜菜甘蓝夜蛾防效达74.8%～93.2%,高于速克毙,甜菜根产量提高29.4%。     

DNA分子标记技术在印楝研究中的应用进展

总结了国内外有关DNA分子标记技术在印楝研究中的应用情况。对RAPD、AFLP、SSR等DNA分子标记技术分别在印楝的遗传多样性、基因流和异交率的测定、体细胞无性系变异方面进行详细的叙述,并指出了DNA分子标记技术在印楝中的发展方向。     

Assessment of genetic diversity and genetic relationships among 29 populations of <Emphasis Type="Italic">Azadirachta indica</Emphasis> A. Juss. using RAPD markers

Randomly amplified polymorphic DNA (RAPD) analysis was employed to assess genetic divergence among 29 neem accessions collected from two agro-ecological regions of India (11 agro-climatic sub-zones), which cover three states, Punjab, Haryana and Rajasthan. Out of 24, 10-mer random primers used for studying genetic divergence, 14 were polymorphic, generating a total of 73 amplification products with an average of 5.21 products per polymorphic primer and estimated gene diversity of 0.49. Genetic relationships among accessions were evaluated by generating a similarity matrix based on Jaccard’s coefficient, ranging from 0.70 to 0.96. The phenetic dendrogram generated by UPGMA analysis grouped accessions into five clusters. RAPD performed within accessions (individual seedlings collected from the same mother plant) showed no variation indicating homogeneous population within accessions. Primers OPA-18, OPC-08 and OPI-03 were found most informative based on their resolving power. The degree of genetic variation detected among the 29 accessions with RAPD analysis suggests that RAPD can be used for studying genetic diversity in neem. The study also demonstrated that neem germplasm collected from northwestern plains of India shows no eco-geographical isolation based on sub-zones because accessions collected from different sub-regions are grouping together in the genetic tree.     

Impact of neem (Azadirachta indica A. Juss) seed cake upon selective nutrient cycling bacterial population in fish culture

With an objective to examine neem seed cake as bactericide, three treatments—10, 20, and 30 mg L^?1—were applied in outdoor experimental Labeo rohita culture tanks for a period of 120 days. Nitrifying, ammonifying, and denitrifying bacteria declined directly with increasing dosage. Ammonifying and phosphate solubilizing bacteria recovered within a month, nitrifying and denitrifying bacteria after 45 days. A positive relationship was established between soil available-N and ammonifying, nitrifying, and denitrifying bacteria in 10 mg L^?1 (R² = 0.68–0.83). Phosphate solubilizing bacteria responded directly with dosage and contributed significantly to the orthophosphate pool (R² = 0.66–0.78).     

两性不育灭鼠剂印楝油对高原鼠兔摄食量的影响及药效试验研究

通过对高原鼠兔野外饲养和印楝油摄食量的药效观察试验,选取高原鼠兔90只,分成2个试验组和1个对照组,各试验组投药浓度为30％和40％的印楝油;对照组饲喂青草,用药7d。试验期间观察各组鼠兔的临床表现,每天记录颗粒剂的采食量,并计算摄食系数;停药后27d处死,剖检雄雌鼠,做病理切片,剖开雌鼠子宫,统计怀孕率。结果表明,高原 药浓度 、40％的颗粒剂的摄食率分别为11．09％和25．10％,差异显著（P〈0．05）;筛选出主药浓度为40 两性不 颗粒剂适口性良好,对高原鼠兔有良好的抗生