腾格里沙漠南缘3种优势植物种子出苗对土壤类型和沙埋的响应

沙米（Agriophyllum squarrosum）、沙蒿（Artemisia sphaerocephala）和油蒿（Artemisia ordosica）分别是腾格里沙漠南缘不同植被演替阶段的3个优势物种,2009年5～6月在大田盆栽条件下,设计了2种土壤类型和0 cm,1 cm,2 cm,3 cm,4 cm,6 ...     

Effectiveness of thiamethoxam and imidacloprid seed treatments against Bemisia tabaci (Hemiptera: Aleyrodidae) on cotton

BACKGROUND: Bemisia tabaci (Gennadius) biotype B is one of the most important pests on cotton around the world. Laboratory, greenhouse and field experiments were conducted to determine the efficacy of thiamethoxam and imidacloprid seed treatments against B. tabaci on cotton. RESULTS: Under laboratory conditions, the two treatments caused whitefly adult mortality, reduced oviposition and increased mortality of nymphs at 10, 20, 30 and 40 days after germination (DAG). The longer the adults fed on plants from treated seeds, the higher the mortality. The two treatments did not have any effect on eggs. The efficacy of the treated seeds against B. tabaci gradually decreased from 10 to 40 DAG, being the lowest at 40 DAG. In laboratory experiments, the efficacies between the two treatments were similar. In greenhouse experiments, the two treatments were equally effective with lower numbers of whiteflies than untreated controls. With both treatments the concentrations of the active ingredient were gradually reduced with aging of the plants and from the bottom to the top leaves of the plants. Numbers of live whiteflies were well correlated with the dosage of active ingredients. Under field conditions, the seeds treated with both insecticides exhibited similar efficacy against B. tabaci for up to ～2 months. CONCLUSION: Cotton seeds treated with imidacloprid and thiamethoxam were effective against B. tabaci for up to 45 days under laboratory and greenhouse conditions, and up to ～2 months under field conditions. Use of imidacloprid‐ and thiamethoxam‐treated seeds can be an important alternative for management of whiteflies on cotton. Copyright © 2010 Society of Chemical Industry     

Analysis of the seed dispersal patterns of wild soybean as a reference for vegetation management around genetically modified soybean fields

There are concerns that genetically modified soybean might threaten the genetic diversity of the wild soybean populations that are distributed in East Asia because genetically modified soybean has no crossing barrier with wild soybean. A simple and effective method to prevent hybridization via pollen flow is spatial separation between the two species because their hybridization occurs only when they grow in close proximity. Therefore, the invasiveness of wild soybean needs to be known in order to secure the appropriate distances. As wild soybean seeds are dispersed mechanically by pod dehiscence, an experiment was conducted in which white sheets were placed on the ground, concentric circles were drawn around the parent plants, and the number of dispersed seeds within each 0.5 m‐wide zone were counted. About 40% of the produced seeds were dispersed and the number of dispersed seeds gradually declined as the distance from the parent plants increased. The model that explained the relationship between the number and distance of the dispersed seeds was produced by using a generalized linear model procedure. More than 95, 99, and 99.9% of the produced seeds stayed within 3.5, 5.0, and 6.5 m after natural pod dehiscence. Knowing these values is useful for evaluating the level of invasive risk by mechanical seed dispersal. The goal of the work is to efficiently and deliberately prevent hybridization by isolating genetically modified soybean fields and wild soybean populations by vegetation management, including weeding and setting up specific‐width buffer zones.     

Integration of soil application and seed treatment formulations of Trichoderma species for management of wet root rot of mungbean caused by Rhizoctonia solani

BACKGROUND: The efficacy of seed dressing and soil application formulations from the isolates of Trichoderma viride (IARI P1; MTCC 5369), T. virens (IARI P3; MTCC 5370) and T. harzianum (IARI P4; MTCC 5371) were evaluated individually and in combination in pot and field experiments during the rainy seasons of 2005, 2006 and 2007 for the management of wet root rot (Rhizoctonia solani) and improvement in the yield of mungbean. RESULTS: A seed dressing formulation, Pusa 5SD, and soil application formulations, Pusa Biogranule 6 (PBG 6) and Pusa Biopellet 16G (PBP 16G), based on Trichoderma virens, were found to be superior to other formulations in reducing disease incidence and increasing seed germination and shoot and root lengths in mungbean. In field experiments, a combination of soil application with PBP 16G (T. virens) and seed treatment with Pusa 5SD (T. virens) + carboxin was superior to any of these formulations individually in increasing seed germination, shoot and root lengths and grain yield and reducing wet root rot incidence in mungbean. Seed treatment was more effective than soil application for all the evaluated parameters. The combined application of Pusa 5SD and carboxin was also superior to individual treatment. CONCLUSION: The efficacy of the evaluated formulations against wet root rot of mungbean proved that the integration of soil application of PBP 16G and seed treatment with Pusa 5SD + carboxin is highly effective for the management of wet root rot, increasing plant growth and grain yield of mungbean Copyright © 2011 Society of Chemical Industry     

麻竹控制授粉种子播种品质及苗期生长观察

该文对麻竹人工授粉种子的播种品质和实生苗的生长发育进行了研究 ,结果表明 :两次授粉所得麻竹种子带壳千粒重和去壳千粒重分别为 12 1 2 9、91 2 9g和 63 87、41 89g ,种子平均净度为 75 72 % ,母竹移植当年第 1次授粉种子含水量为 61 3 3 % ,种子平均生活力为 89 93 % ,场圃发芽率为 58 19% .麻竹实生苗在第 1次移苗时成活株数为 13 95株 ,成苗率为 69 2 6% ,平均苗高 19 5cm .麻竹实生苗分化较明显 ,存在一定比例的白化苗 ,正常幼苗生长差异也较大 ,为开展麻竹优良无性系早期选择提供了依据     

马铃薯交联淀粉醋酸酯的制备工艺及特性

马铃薯原淀粉在水相体系、碱性条件下与醋酸酐作用，生成马铃薯淀粉醋酸酯，然后与交联剂进行交联反应，得到马铃薯交联淀粉醋酸酯。通过改变反应温度、反应时间、pH值和交联剂用量等条件，得出制取马铃薯交联淀粉醋酸酯的最佳工艺条件：反应温度35℃，pH值11，反应时间2 h，交联剂用量2%。所制取的马铃薯交联淀粉醋酸酯较原淀粉在糊液黏度的稳定性、抗老化性、抗分离性等方面均有较大的改善。     

菜籽饼肥不同用量对烤烟产量及质量的影响

试验研究了菜籽饼肥不同用量对烤烟产量和质量的影响。结果表明,施25%熟饼肥 75%复合肥的处理烤烟产量、产值最高,在施用饼肥纯N占25%以上时,随着饼肥用量的增加,烤烟产量、产值呈下降态势。饼肥用量相同时,腐熟饼肥产量、产值高于生饼肥。25%熟饼肥 75%复合肥处理的烟叶内在化学品质协调性较好,单施复合肥或单施菜籽饼肥(包括生饼和熟饼肥)都不利于烟叶内在化学品质的协调。     

芒果不同品种果实的显微结构与品质的关系初探

采用紫花芒、桂香芒、红象牙和印度1号芒果的果实,通过扫描电子显微镜观察,发现果实皮孔少,开口小,蜡质密度大的紫花芒果实耐贮藏。分泌腔多的桂香芒和印度1号果实芳香味浓。果肉薄壁细胞中淀粉粒增多,果实愈趋近成热。薄壁细胞中淀粉粒多的桂香芒,果实后熟后含糖量高。     

元谋干热河谷山地植被修复区土壤种子库研究

 为了解干热河谷不同植被修复方法的土壤种子库的变化模式,采用对不同处理地段(包括水平阶间坡面、自然坡面、沟底)和对照(放牧地)的土壤种子库组成、大小进行比较研究的方法,研究元谋干热河谷山地植被修复区的土壤种子库。结果表明:1)植被修复区土壤种子库密度、丰富度均大于对照区;2)修复区内第2年土壤种子库密度、丰富度均大于第1年;3)水平阶间坡面和各类型间的土壤种子库密度差异显著;4)种子库中草本植物占很大比例;5)孔颖草和扭黄茅是种子库2大优势种。研究项目所采取植被修复措施在很大程度上改善土壤种子库的数量结构和物种组成。