几种农药颗粒剂对月季蚜虫防治效果研究

研究了6种颗粒剂对月季蚜虫防治效果及持效期,以期筛选出对蚜虫防治速效性及持效期优良的新型颗粒剂,替代高毒农药颗粒剂。调查根埋施药后7 d、16 d、24 d、44 d对月季蚜虫的防治效果;并进行数据处理分析。研究结果表明:2%吡虫啉颗粒剂1.5 g、4.5 g处理和0.5%阿维菌素颗粒剂9 g处理,在防治月季蚜虫的速效性和持效期方面,显著高于其他药剂处理,可以作为高毒药剂3%呋喃丹颗粒剂的替代品。综合防治的速效性、持效期、经济性和药剂安全性方面,2%吡虫啉颗粒剂每株施药1.5 g最优,具有较大的应用价值。     

气候因素与苜蓿蚜种群数量变化规律初探

西宁地区苜蓿蚜种数量随气候变化的增长曲线呈“Ｓ型”其数学模型为：Ｙ＝９８４９／１＋ｅ＾８．９３２５＋０．６９４９ｔ,蚜量最快增长期为６月中旬至７月初;蚕豆生育期内月平均干燥度指数Ｋ〉２．００以上,气候为干旱和很干旱等级时,蚜虫种群数量增长与同期≥５℃的积湿呈指数递增关系。     

西宁地区油菜蚜虫寄生蜂及重寄生蜂初步研究

西宁地区油菜蚜虫的寄生蜂为菜蚜茧蜂、燕麦蚜茧蜂和烟蚜茧蜂,优势种为菜蚜茧蜂,重寄生蜂为蚜虫金小蜂,雌雄性比分别为1．26：1、1：1、1：1和1．27：1．桃蚜和甘蓝蚜寄生蜂的寄生率在11．5％～18％之间,甘蓝蚜较低,在0．73％～1．44之间．蚜茧蜂在三种蚜虫上的寄生孵化率大约在85％左右,在西宁三个不同地区的寄生孵化率约为75％．     

新疆垦区蚜虫染色体组型分析

从外部形态和染色体两个方面，对新疆垦区７种蚜虫进行研究。在这７种蚜虫中，染色体数目范围由２ｎ＝６至２ｎ＝１８，出现频率最高的是２ｎ＝８和２ｎ＝１２。根据染色体的数目、形态和长度，总结出６种染色体组型，并讨论了它与普通形态分类学之间的关系。     

麦长管蚜实验群种的研究

麦长管蚜是我国华北冬麦区的重要害虫,为制订出防治麦长管蚜的最优决策,我们进行了麦长管蚜实验种群的研究,分析了麦长管蚜与主要环境因子温度、湿度之间的关系,并建立了依赖于温度、湿度的麦长管蚜生长发育模型和内禀增长率模型.为预测麦长管蚜的发生动态提供了依据,为防治麦长管蚜最优决策的提出奠定了基础.     

Induction of phenylalanine ammonia-lyase and lipoxygenase in cotton seedlings by mechanical wounding and aphid infestation

Plants have developed a multitude of inducibledefense mechanisms against aggressive biotic and abi otic agents[1]. Wound and herbivory induced plantresponses can negatively affect herbivore’s physiologydirectly by stimulating the synthesis of toxic metabo lites[2—4]. In addition to such direct defense mecha nisms, plants can also emit specific blends of volatilesthat attract carnivorous enemies to defend themselvesagainst herbivores[5—9].Herbivory induced plant volatiles can n…     

Induction of phenylalanine ammonia-lyase and lipoxygenase in cotton seedlings by mechanical wounding and aphid infestation

It has been suggested that infestation of plants causes increases in the activities of phenylalanine ammonia-lyase (PAL) and lipoxygenase (LOX), key enzymes in the phenolic compounds synthesis pathway and the octadecanoid pathway, respectively. The purpose of this work is to investigate whether the infestation of cotton aphid （Aphis gossypii） and mechanical wound can cause the induction of PAL and LOX activities in cotton seedlings, and whether the induction occurs in healthy seedlings growing nearby the attacked ones. The specific activities of PAL and LOX were measured using spectrophotometric method after aphid infestation and mechanical wounding. Result indicated that PAL activity and LOX activity were greatly induced by mechanical wounding and aphid infestation in cotton seedlings. The induction of PAL and LOX occurred not only in wounded and infested seedlings but also in intact healthy seedlings growing nearby. After exposed to the aphid infestation-induced volatiles, the specific activity of PAL in cotton seedlings increased by 6% at 24 h, 80% at 48 h, 235% at 72 h compared to the control, and the specific activity of LOX increased by 18% at 24 h, 34% at 48 h, 24% at 72 h, respectively. In comparison, the specific activity of PAL in unwounded seedlings exposed to wound-induced volatiles increased by 0.0 at 24 h, 200% at 48 h, 164% at 72 h, respectively and the specific activity of LOX increased by 28% at 24 h, 37% at 48 h, 8% at 72 h, respectively. It suggests that the induced volatiles are involved in plant-plant communication as airborne transferred signals.     

十一星瓢虫捕食棉蚜的种群动力学模型及其数值模拟

根据棉蚜、十一星瓢虫的生物学特性以及新疆棉区十一星瓢虫对棉蚜捕食作用的调查和实验数据,建立了十一星瓢虫捕食棉蚜的种群动力学理论模型.在模型中对捕食者─十一星瓢虫进行了虫态和年龄结构划分,用来模拟不同虫态和年龄结构瓢虫对蚜虫的捕食.运用有限差分法对建立的模型进行了数值模拟,将模拟结果与实际调查数据进行比较,验证了模型的准确性和实用性.     

野苋菜凝集素基因的克隆及抗蚜性

通过PCR从苋科植物野苋菜Amaranthus viridis L.基因组DNA中扩增出野苋菜凝集素的核基因片段AVA。序列分析结果表明该基因为1831 bp,含有一个922 bp的内含子和两个分别为212 bp和697 bp的外显子。采用反向PCR技术获得了该基因的编码区克隆。分别构建含有内含子和不含内含子的AVA基因植物表达载体pBI121AVA-GUS和pBI121AVAc-GUS,通过根癌农杆菌介导法转化烟草。PCR、GUS检测结果均表明AVA基因不仅已整合到烟草基因组DNA中,而且初步表明转基因烟草有AVA蛋白表达。抗蚜实验表明含内含子和无内含子的AVA基因在转基因烟草中的抗蚜能力不同,转AVA和AVAc烟草对蚜虫的抑制率分别为60.81%和50.63%,有的植株高达97%。实验结果表明所克隆的AVA基因是具有抗蚜能力的苋菜凝集素基因家族中的新成员。