Dry mycelium of<Emphasis Type="Italic">Penicillium chrysogenum</Emphasis> induces resistance against verticillium wilt and enhances growth of cotton plants

Dry mycelium (DM) ofPenicillium chrysogenum and its water extract (DME) were examined for their effects on induced resistance against Verticillium wilt and plant growth of cotton in the greenhouse. Soil application of 0.1–5% DM or 0.5–5% DME provided significant protection against the wilt, relative to the control. As neither DM nor DME inhibited mycelial growth ofVerticillium dahliae in vitro, it is suggested that the disease-controlling effects of DM or DME are attributed to induced resistance. DME (5%), as well as DME treated with chloroform or cold acetone, were as effective as 2% DM in reducing disease severity of Verticillium wilt, implying that the resistance-inducing substance(s) in DM are mostly water-soluble, with neither proteins nor lipids likely to be responsible for the induction of resistance. No significant difference in root colonization withV. dahliae was found between control-inoculated and 2% DM- or 5% DME-inoculated plants. However, colonization of hypocotyls and epicotyls was drastically suppressed by either 2% DM or 5% DME relative to the control. Treatments with 2% DM or 5% DME significantly increased ionically-bound peroxidase (POX) activity in roots, hypocotyls and the second leaf of cotton plants, with the hypocotyls expressing the highest increase. Soil application of DM or DME increased plant height, fresh and dry weight of inoculated and non-inoculated cotton plants, relative to their corresponding controls. It is concluded that DM may be used in cotton crops to promote plant growth and to induce resistance againstV. dahliae. POX might be associated with the defense against Verticillium wilt. http://www.phytoparasitica.org posting Jan. 9, 2002.     

嫁接对茄子生长发育和黄萎病抗性的影响

利用茄属野生种粘毛茄作砧木，六叶茄为接穗进行嫁接，探讨嫁接对茄子抗黄萎病能力及生长发育的影响。经接种鉴定，嫁接苗比六叶茄自根苗（ＣＫ）病情指数下降５５．４，春大棚生产试验中，嫁接苗未发现病株，表明嫁接能显著提高茄子对黄萎病的抗性；砧木与接穗之间有较强的亲和性，嫁接苗成活率３年平均达８９．６％，且嫁接苗根系极其发达，根体积超过对照１倍以上，明显促进了地上部各器官的生长，果实产量显著提高，１９９５、１９９６年嫁接苗茄子产量分别比对照增产３５．１％和２６．８％。     

Note: Extrapolating the use of an entomopathogenic nematode and fungus as control agents forFrankliniella occidentalis toThrips palmi

Little is known regarding non-chemical control measures againstThrips palmi Karny. Since entomopathogenic fungi and nematodes have been found to be active against thrips species such asFrankliniella occidentalis Pergande, comparative bioassays were conducted to determine the extent to which they also show activity againstT. palmi. Significant mortality of the larvae of the species was recorded following treatment withLecanicillium muscarium (Petch) Zare and Gams, and addition of the wetting agent Agral enhanced pathogenicity toT. palmi. T. palmi pupae were not affected byS. feltiae. The potential for use of these agents againstT. palmi in the field is discussed in the light of these results. http://www.phytoparasitica.org posting Aug. 28, 2005.     

紫荆黄萎病病原菌研究

在紫荆树上发现1种紫荆新病害 紫荆黄萎病,病叶症状有2种类型：一种为灰绿色干枯型,主要表现为叶片从边缘开始失水萎蔫,逐渐向叶片中心扩展,后期整个叶片皱缩卷曲、质地较脆,呈现灰绿色焦枯状;另一种为黄色萎蔫型,前期叶片从边缘开始变黄萎蔫,逐渐向内部扩展,病健交界处有明显界限,后期叶片皱缩,颜色呈现淡黄色到淡橘黄色。发病枝条的维管束呈浅橘红色或褐色,病叶不脱落。依据Koch’s准则证明,分离物CC001是引起该病害的病原菌。对CC001菌株的rDNA ITS区段进行PCR扩增和测序,并结合形态学特征鉴定为大丽轮枝菌（Verticillium dahliae）。寄主范围测定结果表明,该病菌还可以侵染马铃薯和棉花。该研究是国内关于紫荆黄萎病的首次报道。     

新疆几株黄萎轮枝菌株的形态学鉴定与生物学特征特性比较研究

采集新疆南北棉区的棉花症状表现为黄斑型和落叶型的以及从茄与苍耳上分离得到的黄萎轮枝菌共6个菌株，进行了形态学及生物学特征特性的比较研究。结果表明，6菌株都无形态学上的显著差异，其生物学特征特性也基本雷同。6个菌株同在棉、红花、向日葵、茼麻、苍耳和辣椒上作交互接种，均表现为不侵染辣椒，但对其他的6种供试植物均持不同程度的致病力现象。以茄菌与苍耳菌对供试的6种植物的致病力都强，而寄生在棉花上的4个菌株除对其原寄主的致病力为中、强度外，对红花、向日葵、苍耳及苘麻的致病力也强，但对茄的致病力则弱，或无致病能力。本试验6个菌株均应被鉴定为大丽花轮枝菌（Verticillium dahliae Kleb．），但从其全部的表现形式看仍有较明显的生理分化现象。从棉花上的4个菌株表现的形式可以看出，南北疆棉黄萎病的黄斑型与落叶型分离物均同属于中、强度侵染的致病菌，在许多情况下，黄斑型菌株的致病力还往往强于落叶型菌株的致病力，从当前南北疆棉区的棉花黄萎病中表现有落叶型反应的病株，很难断定为系属强致病力变异菌株的症状反应。     

棉花落叶型黄萎病的发生规律及损失率测定研究

1997- 1 999年在三余镇棉田系统调查结果 ,棉花落叶型黄萎病在本区有 2个发病高峰 ,分别出现在 7月中、下旬和 8月下旬或 9月上旬 ,病害发生消长与气温、雨日、雨量及相对湿度密切相关 ,在适宜温度 ( 2 2～ 2 8℃ )范围内雨水多而均匀 ,则发病重。病害危害棉株后 ,对产量的影响主要表现为结铃数减少 ,铃重下降 ,病指与产量呈负相关。     

中国棉花抗枯、黄萎病育种50年

 综述了我国棉花抗枯、黄萎病育种研究进展 ,内容包括 5 0年来取得的成就、经验 ,存在的问题及对策 ,是对我国棉花抗病育种工作较为全面的总结。     

棉花抗黄萎病育种研究现状及对策

介绍了我国棉花抗黄萎病育种研究的现状 ,分析了影响棉花抗黄萎病育种研究的因素 ,提出了加快抗黄萎病育种研究进程的对策和建议。     

棉花黄萎病生物防治研究

论述了防治棉花黄萎病的拮抗微生物以及利用诱导抗性来防治棉花黄萎病的研究进展,并提出了棉花黄萎病生物防治中存在的问题和今后发展的趋势.