陕西设施蔬菜根结线虫生防菌株JXC224的分离筛选

几丁质及蛋白质是构成根结线虫体壁和卵壳的主要物质。几丁质酶和蛋白酶活性的高低是评价生防真菌防治潜力的重要生化指标。从陕西省陕北关中陕南根结线虫病害严重的设施蔬菜大棚中采集土样、根结样106份,用分离培养基分离到真菌436株。液体发酵测定分离菌株的几丁质酶活及蛋白酶活,筛选获得几丁质酶活≥0.06 U/mL的菌株11株,蛋白酶活≥100 U/mL的菌株3株。其中JXC224几丁质酶活达0.087 U/mL,蛋白酶活125.8 U/mL,对根结线虫二龄幼虫的侵染率达67%,是一株具有开发潜力的生防菌株,经ITS测序分析,鉴定其为枝顶孢霉(Acremonium sp.)。     

禾谷孢囊线虫(Heterodera avenae)纤维素结合 蛋白基因(Ha-cbp-1)的克隆和序列分析

 禾谷孢囊线虫(Heterodera avenae)是中国小麦上的重要病原线虫。纤维素结合蛋白基因是一种重要的植物线虫寄生和致病相关基因。用同源克隆的方法从禾谷孢囊线虫寄生前二龄幼虫中克隆出一种纤维素结合蛋白新基因Ha-cbp-1（GenBank 注册号GQ178086）cDNA序列。Ha-cbp-1基因cDNA包含1个开放阅读框,编码131个氨基酸残基的蛋白质,预测蛋白由1个长度为18氨基酸残基的信号肽和1个纤维素结合区域（CBD）组成。Ha-cbp-1的基因组DNA序列含有2个内含子。预测的禾谷孢囊线虫纤维素结合蛋白（HA-CBP-1）序列与大豆孢囊线虫纤维素结合蛋白（HG-CBP-1）序列有60%的同一性和76%的相似性,与甜菜孢囊线虫纤维素结合蛋白（HS-CBP-1）序列有60%的同一性和75%的相似性。本研究首次从禾谷孢囊线虫中成功克隆出CBP蛋白基因。     

芹菜根结线虫病对产量的影响与防治指标研究

研究表明,由于病原线虫危害使芹菜根系受损,单株地上部分鲜重明显减少从而造成减产,其单位面积的产量随着病情指数的上升而下降。经一元非线性数学模型回归模拟分析,芹菜定植后45d的根结线虫病病情指数㈤与产量损失率（Y）之间均存在极显著的相关性,其数学回归模型方程为Y=0．026IX^1.6429（RR=0．9905^＊＊）。以此为基础,建立了芹菜根结线虫病的防治指标动态模型。     

新型低毒杀虫剂防治花生地下害虫初步研究

用新型低毒杀虫剂和小杆线虫制剂对花生地下害虫蛴螬和金针虫进行了大田防治研究。结果表明:在花生开花下针期施用15%毒死蜱颗粒剂对蛴螬的杀虫效果最佳,在花生开花下针期施用25%毒死蜱颗粒剂对花生果实免受蛴螬危害的效果最好。小杆线虫2号制剂对蛴螬的防治效果优于小杆线虫1号制剂,增产效果显著。30%辛硫磷微囊悬浮剂对花生田金针虫的保果效果和杀虫效果最好。     

中国禾谷类大田作物收获指数和秸秆系数

收获指数是作物科学研究和生产中的重要指标,秸秆系数是评估秸秆量的重要参数。本项研究通过查阅2006—2010年发表的大田试验研究的原创性论文,获得了禾谷类作物在中国大陆地区主产省市自治区的收获指数及换算后的秸秆系数。结果表明:水稻的收获指数和秸秆系数全国平均值分别为0.50和1.00,其中16个省市自治区的变幅为在0.43～0.54和0.85～1.33。玉米的收获指数和秸秆系数全国平均值分别为0.49和1.04,其中12个省市自治区的变幅为0.42～0.53和0.89～1.38。小麦的收获指数和秸秆系数全国平均值分别为0.46和1.17,其中11个省市自治区的变幅为0.42～0.50,秸秆系数为1.00～1.38。其他谷类作物的收获指数为0.17～0.49,秸秆系数为1.04～4.88。和前人的研究结果相比,在过去的20多年里,中国主要禾谷类作物的收获指数虽然有明显的提高,但是进一步上升的空间变小。未来要进一步增加作物的经济产量,通过提高收获指数已不再是其主要途径,而要通过增加生物产量以提高其单位面积的经济产量。     

Testing and modelling the potential of three diploid plants in Poaceae as a new pathosystem to investigate the interactions between cereal hosts and cereal cyst nematode (Heterodera avenae)

Cereal cyst nematode (CCN), Heterodera avenae, is one of the most important pathogens of wheat worldwide, and causes significant yield losses. Research on CCN–wheat interactions is hampered by the lack of an effective model pathosystem. This study investigated the potential of the model cereal Brachypodium distachyon (Bd21‐3) and diploid wheat 2A (G1812) and 2D (AL8/78) as model hosts for CCN. Nematode infection analysis showed that although some CCN penetrated Bd21‐3 roots, these nematodes failed to develop to the later developmental stages or form cysts, indicating B. distachyon is not a host for CCN. A strong burst of reactive oxygen species (ROS) within Bd21‐3 roots infected with CCN was induced 3 days after infection and the expression of seven ROS‐producing genes was significantly increased. In contrast, CCN completed its life cycle in both diploid wheat 2A and 2D, and formed normal syncytia in these hosts. Although CCN developmental processes within both diploid wheat 2A and 2D were very similar to those in the susceptible control, the number of cysts formed on diploid wheat 2D was less than those formed on diploid wheat 2A and the susceptible control, indicating that diploid wheat 2A was a more suitable host for CCN than 2D. This is the first report of a potential new pathosystem for CCN–host interactions using diploid wheat.     

植物寄生线虫体内病毒检测方法研究进展

线虫作为植物病毒重要的传播媒介之一,引起病毒病的传播和蔓延。本文综述了近年来线虫介体体内植物病毒的检测方法,有电子显微镜检测法、血清学检测法、PCR检测法等,以期为我国开展该方面工作提供参考。     

芒果果粒谷物酸奶的研制

对芒果果粒谷物酸奶的产品配方及发酵条件进行研究,通过配料优化组合,用3因素3水平正交试验确定产品配方及工艺参数.结果表明:牛乳中加入8％白砂糖、2.5％谷物粉、0.15％明胶、0.15％果胶、0.40％变性淀粉、250DCU/t直投式乳酸菌,在42.5℃条件下发酵5h后,加入10％芒果果粒,搅拌冷却后,所得芒果果粒谷物酸奶细腻、光滑、清新、风味独特.     

Dose-response effects of clove oil from Syzygium aromaticum on the root-knot nematode Meloidogyne incognita

BACKGROUND: Clove oil, derived from the plant Syzygium aromaticum (L.) Merr. & Perry, is active against various organisms, and was prepared in a soy lecithin/detergent formulation to determine concentrations active against the root-knot nematode Meloidogyne incognita (Kofoid and White) Chitwood. RESULTS: In microwell assays, the mean effective clove oil concentration that reduced egg hatch by 50% (EC(50)) was 0.097% (v/v) clove oil; the EC(50) for second-stage juvenile (J2) viability was 0.145% clove oil (compared with carrier control treatments). Volatiles from 5.0% clove oil reduced nematode egg hatch in water by 30%, and decreased viability of hatched J2 by as much as 100%. Reductions were not as large with nematodes in carrier. In soil trials with J2 recovered from Baermann funnels, the EC(50) = 0.192% clove oil (compared with water controls). CONCLUSION: The results demonstrated that the tested formulation is active against M. incognita eggs and J2, that the EC(50) values for J2 in the microwell studies and the soil recovery tests were similar to each other and that direct contact with the clove oil is needed for optimal management results with this natural product.     

野生大豆内生芽孢杆菌BHL3501的鉴定及对大豆胞囊线虫的抑制作用

[目的]鉴定野生大豆内生芽孢杆菌BHL3501并研究其对大豆胞囊线虫的抑制作用。[方法]通过形态学特征、生理生化特征及16S rDNA分析,鉴定了从野生大豆根中分离筛选到的1株具有杀线虫活力的内生细菌BHL3501,并研究了BHL3501菌株代谢物不同倍数稀释液对大豆胞囊线虫卵孵化及2龄幼虫活力的影响。[结果]BHL3501菌株初步鉴定为芽孢杆菌Bacillus sp.。其发酵原液处理24h后对大豆胞囊线虫卵孵化的相对抑制率为98.3%;10倍稀释液处理下相对抑制率为79.5%,均与无菌水对照差异显著。发酵原液处理24 h后,2龄幼虫的校正死亡率为93.1%,各稀释浓度处理均与无菌水对照差异显著。[结论]BHL3501代谢物对大豆胞囊线虫卵孵化有强烈的抑制作用,对其2龄幼虫有较强的毒杀作用。