不同抗性玉米自交系感蚜期四种酶活性变化分析

本试验对网棚隔离和大田种植条件下3种玉米自交系感蚜期叶片和雄穗内PPO、POD、PAL、ASA-POD活性变化进行了测定分析。结果表明,自然感蚜后3种感性材料PPO、POD活性在不同时期的叶片和雄穗内都明显增高;PAL活性在不同时期的叶片和衰落期、消亡期的雄穗内有所升高;ASA-POD活性在不同时期雄穗内有所增高。3种感性材料隔离状态和自然感蚜状态下＂9401＂叶片PPO活性在衰落期和消亡期最低,PAL活性在盛蚜期和衰落期均最低,表现为随抗性降低而降低;＂9401＂雄穗POD活性在衰落期和盛蚜期最高,ASA-POD活性在盛蚜期最高,表现为随抗性降低而增高。     

高巧种衣剂包衣对棉种发芽及棉蚜防治效果的影响

利用高巧60%悬浮种衣剂对种子进行包衣,研究了高巧包衣对棉种出苗以及棉蚜防治效果的影响。结果表明:高巧60%悬浮种衣剂包衣对棉种出苗无明显影响,对防治棉花春蚜有较好效果和较长的特效期。     

桉树枝瘿姬小蜂中国本地自然天敌调查与捕食性天敌的捕食观察

文章首次报道了桉树枝瘿姬小蜂在中国的捕食性自然天敌。2009年9-12月,以华南农业大学校园窿缘桉（Eucalyptus exserta）和巨园桉（Eucalyptus grandis×E.tereticornis）DH201-2林分为材料,进行林间肉眼观察,并收集桉树枝瘿姬小蜂（Leptocybe invasaFisher＆La Salle）虫瘿羽化出的昆虫,解剖观察虫瘿中的昆虫,调查桉树枝瘿姬小蜂自然天敌。结果发现：3种桉树枝瘿姬小蜂捕食性自然天敌分别为冠猫跳蛛（Carrhotus coronatus）、斜纹猫蛛（Oxyopes sertatusL.Koch）和圆蛛（Cyrtarachnesp.）,其中冠猫跳蛛是优势种。对冠猫跳蛛捕食桉树枝瘿姬小蜂情况进行野外和室内试管观察,统计其捕食量为野外4.8头/头.h、试管内0.36头/头.h。未发现桉树枝瘿姬小蜂寄生性天敌。     

Mitochondria and Cytoplasmic Male Sterility as Related to Southern Corn Leaf Blight

Abstract

The use of one source of cytoplasmic male steriity, leading to widespread uniformity of maize, coupled with the appearance of a new virulent race of Helminthosporium maydis made the Southern Corn Leaf Blight epidemic possible. The weather during 1970 was very suitable for the spread of the disease and thus the epidemic occurred. The possible role of cytoplasmic DNA, carried most probably by the mitochondria, in the susceptibility or resistance of various maize lines in discussed. The relationship of cytoplasmic male sterility and disease resistance or susceptibility is considered. The effects of the pathotoxin, produced by H. maydis, its uses as an experimental tool in research, and its potential uses in further investigations are described in detail.     

Armyworm Control

Abstract

An account is given of the African armyworm, Spodoptera exempta (Walk.), as a noctuid pest of agriculture, and of the recent research into its biology and control in East Africa. Salient features in its biology and zoogeography are discussed, from the standpoint of the way in which they determine control methods and strategy. Special attention is given to the forecasting of outbreaks. Comparative reference is made to forecasting systems and techniques as practised in other countries and with different insects.     

棉田棉蚜自然种群生命表

采用分代隔离观测等方法，研究了棉蚜自然种群特定年龄生命表，共获得５个世代数据。分析结果表明，影响棉蚜自然种群波动的主要因素是气候条件和天敌     

Nitrogen Fixation,Ureide, and Nitrate Accumulation Responses to Soybean Aphid Injury in Glycine max

There is little information available about soybean aphid (Aphis glycines Matsumura) effects on the physiology and mineral nutrition of soybean (Glycine max [L.] merr.). Controlled-environment studies were conducted to measure soybean aphid infestation effects on dry weight, nitrogen (N) fixation, ureide-N, and nitrate-N concentration and accumulation. Plants grown in perlite using –N nutrient solution culture were infested at the 3rd trifoliolate (V3) stage and measured for N fixation, nodule characteristics, and ureide-N concentration at the full pod (R4) stage. When compared to uninfested control plants, aphid infestation reduced total nodule volume per plant by 34%, nodule leghemoglobin per plant by 31%, plant N fixation rate by 80% and shoot ureide-N concentration by 20%. Soil-grown plants were infested at the first trifoliolate (V1) stage and shoots were measured for dry weight, nitrate-N, and ureide-N at the full bloom (R2) stage. Infestation reduced shoot dry weight by 63%, increased nitrate-N concentration by 75%, but did not significantly affect ureide-N concentration. Because nutrient concentration is a single-point measurement that results from the integration of two dynamic processes, nutrient accumulation and dry matter production, we conclude that aphid-induced reductions in N fixation, coupled with decreased dry weight accumulation, caused shoot ureide-N concentration to remain unchanged in aphid-injured plants when compared to uninfested plants. Because nitrate-N concentration was greater in aphid-damaged shoot tissue, we further conclude that nitrate-N accumulation was less sensitive to aphid injury than dry weight accumulation.     

棉蚜对新烟碱类杀虫剂的抗性现状及其治理策略

棉蚜Aphis gossypii Glover是棉花生产中最严重的害虫之一。长期以来防治棉蚜主要依赖于化学杀虫剂,其中新烟碱类杀虫剂扮演着十分重要的角色,但由于其长期、大量的使用,棉蚜已对该类杀虫剂产生了较高水平的抗性,严重影响了对棉蚜的防治效果。抗性机制研究表明,棉蚜对新烟碱类杀虫剂产生抗性的机制主要涉及解毒代谢能力增强和靶标敏感性下降。细胞色素P450、羧酸酯酶、谷胱甘肽S-转移酶、UDP-葡糖基转移酶等解毒酶基因过量表达介导的解毒代谢增强和烟碱型乙酰胆碱受体β1亚基突变引起的靶标敏感性下降是棉蚜对新烟碱类杀虫剂产生抗性的关键。针对我国棉蚜对新烟碱类杀虫剂抗性问题突出的现状,为更好地利用该类药剂防治棉蚜,亟需根据棉蚜抗性机制制定合理的抗性治理策略。本文将从棉蚜对新烟碱类杀虫剂的抗性现状、抗性机制以及抗性治理策略等方面进行综述,以期为抗性棉蚜的科学治理提供参考。     

弗雷生蚜霉菌侵染发病过程的观察

本文报道弗雷生蚜霉菌侵染蚜虫发病过程的主要阶段及其特征。从传播接触、萌发侵入、潜育到症状表现,在20～30℃下,历期一般为3～5天。