水稻新品系红源和台糯选对褐稻虱抗性的评价

应用分泌蜜露量，种群趋势指数，内禀控制率，群体建立和田间控制率等指标，综合评价新品系红源和台糯选对褐稻虱的抗性。结果表明：（１）饲养在红源和台糯选上褐稻虱的成虫体重，分泌蜜露量，产卵量和若虫存活率均比在感品种ＴＮ１的低，表明品系对褐稻虱具有强抗性作用：（２）飞虱在ＴＮ１上的种群趋势指数为２４７．７，台糯选为３８．２，红源为３８．４，而抗虫品种Ｍｕｄｇｏ为１０．６；（３）台糯选，红源和Ｍｕｄｇｏ的内     

酚酸物质减轻黄瓜枯萎病的效果及其原因分析

 选用有机物料分解产生的3种主要酚酸物质——香豆酸、阿魏酸、对羟基苯甲酸,加入土壤可以减轻黄瓜枯萎病,其中对羟基苯甲酸效果最好,其次为阿魏酸,香豆酸效果较差。添加低浓度酚酸物质到土壤中,可以增加细菌数量,增加真菌数量,降低土壤中病原菌所占真菌比例,以对羟基苯甲酸处理效果最突出,其次为阿魏酸,香豆酸较差。添加酚酸物质后土壤中放线菌数量增加,并提高了拮抗尖镰孢菌的能力,以香豆酸处理最突出,其次为阿魏酸,对羟基苯甲酸较差。酚酸物质还可以直接抑制病原菌菌丝伸长。     

Pseudomonas aeruginosa produces secondary metabolites that have biological activity against plant pathogenic Xanthomonas species

The bioactivity of compounds produced by Pseudomonas aeruginosa (LN strain), against three Xanthomonas species was investigated under greenhouse conditions and using electron microscopy. Chromatographic fractions EAP, VLC3, VLC4, VLC3d and VLC4f were tested against Xanthomonas axonopodis pv. malvacearum, X. axonopodis pv. phaseoli and X. axonopodis pv. citri by disc diffusion. Fractions with antibiotic activity were tested in vivo under greenhouse conditions and their bioactivity was evaluated. Scanning electron microscopy showed that VLC4f affects biofilm formation while VLC4f and VLC3d both affect cell morphology. The semi-purified fractions controlled bacterial diseases caused by Xanthomonas spp. when sprayed on plants under greenhouse conditions. The VLC4f fraction showed superior results in disease management, reducing the number of lesions on cotton and orange leaves by 94%, and reducing disease severity in bean leaves by 73%. The data suggest that the fractions were effective and have potential as an alternative to conventional bactericides in the control of plant diseases caused by Xanthomonas sp under greenhouse conditions.     

苔藓植物的生理活性

介绍了苔藓植物的多种药理活性,如抗菌、抗癌、防治心血管系统疾病等。     

Characterization of resistance to Aphis glycines in soybean accessions

The soybean aphid, Aphis glycines Matsumura, is a pest of soybean [Glycine max L. (Merrill)] in Asia, and its recent establishment in North America has led to large, recurring outbreaks that have challenged pest management practitioners there to seek environmentally responsible means for its control. Growth-chamber experiments were conducted to determine and characterize host-plant resistance among several soybean accessions. Soybean plants were first screened for resistance by rating the population growth of A. glycines in two tests. All plants of PI 230977 and 25% of PI 71506 plants were resistant (≤100 aphids per plant) in the first screening test. All ‘Dowling’, PI 71506 and PI 230977 were resistant (≤150 aphids per plant), and 50% of plants of line ‘G93-9223’ were resistant in the second test. Follow-up experiments showed that antixenosis was a modality of resistance based on reduced nymphiposition by A. glycines on Dowling, PI 230977 and PI 71506 in no-choice tests and on fewer numbers of A. glycines on Dowling, PI 230977, PI 71506 and G93-5223 in distribution tests. Antixenosis in Dowling and PI 230977 was stronger in the unifoliolate leaves than in other shoot structures, whereas distribution of A. glycines within plants of PI 71506 and G93-5223 suggested comparable suitability between unifoliolate leaves and other shoot structures of these accessions. Antibiosis to A. glycines was evident as a lower proportion of aphids that reproduced on PI 230977 and from fewer progeny on PI 230977 and Dowling than on 91B91. The number of days from birth to reproduction by A. glycines did not differ among accessions. Results confirmed Dowling and PI 71506 as strong sources of resistance to A. glycines. The levels of antixenosis and antibiosis to A. glycines in PI 230977 and antixenosis to A. glycines in G93-9223 suggest that these accessions may also be valuable to soybean breeding programs as sources of resistance.     

应用主分量分析评价水稻品种对白背飞虱抗生性初探

白背飞虱Sogatella furcifera (Horvath)是我国水稻上的重要害虫之一.尽管化学农药在对白背飞虱的防治中起了一定的作用,但由于施药增加了生产成本,并且长期使用造成了白背飞虱的抗药性、杀伤天敌、诱导害虫再度猖獗;以及引起环境污染.因而近年来抗白背飞虱品种的培育逐渐提到日程上来.为了筛选抗白背飞虱的抗源.我们就初筛和复筛后得到的17个对白背     

Beneficial microbial allelopathies in the root zone: the management of soil quality and plant disease with rhizobacteria

By virtue of their physiological adaptability and metabolic versatility, bacteria in plant root zones are a key agent of change in soil agroecosystems. Interactions between plant root systems and rhizobacteria have a profound effect on crop health, yield, and soil quality. Through the selective release of exudates and leachates plants activate and sustain specific rhizobacterial communities in the root zone. In turn, root zone bacteria are able to generate a wide array of secondary metabolites which can have a positive influence on plant growth; enhancing the availability of minerals and nutrients, improving nitrogen fixation ability, decreasing susceptibility to frost damage, improving plant health through the biocontrol of phytopathogens, inducing systemic plant disease resistance, and facilitating plant establishment, growth and development. The benefits from root zone bacterial biodiversity are moot in managed agroecosystems, where community complexity is minimized, and ecosystem stability is often disrupted for the purpose of disease control and yield maximization. The complexity of plant–soil–microbial interactions are so varied, that a complete understanding of all the relationships involved is unlikely to be achieved, even in a production monoculture. Nevertheless, the consequences of beneficial biological interactions that stimulate crop yields and improve plant health can be evaluated relatively simply and a number of general management strategies can be devised accordingly.     

药用菊花对菊花瘿蚊的抗性研究

以单株虫瘿量作为指标就我国常见的14种药用菊花对菊花瘿蚊的抗性进行鉴定,结果表明,祁菊为高感品种;怀小白菊、小亳菊为感虫品种;温茶菊、杭菊、大亳菊、贡黄菊为抗虫品种;贡白菊及3种野菊花等为高抗品种。抗性机制研究表明,菊花瘿蚊对不同菊花资源的产卵存在选择性差异。各菊花品种瘿蚊蛹重差异不大,但死亡率差异较大,存在抗生性差异。     

Complement of integrated fertilizer management and integrated pest management concepts to ameliorate faba bean growth and yield

Twenty-one microbial preparations recommended for controlling pathogenic fungal strains causing root rot and wilt diseases of faba bean were investigated for antibiosis against several symbiotic and associative diazotrophs adopting a modified agar-plate-inhibition-zone assay. Rhizobium and Bradyrhizobium exhibited a somewhat similar susceptibility to biocontrol agents while associative diazotrophs showed variable responses. Azotobacter, compared to others, was severely inhibited by such bio-candidates. The members of the biofertilizer formulation ‘Biofertan’ did bear mixed cultivation with the majority of biocontrol agents. Among those, Bacillus subtilis was deemed the pioneer. In pot experiments, almost all the antagonists significantly restricted the severity of root rot and wilt diseases besides modifying faba bean seedling stand and improving plant development. This was very obvious with shoot biomass increases of >?50%. Moreover, the bioagents successfully recovered the legume establishment, seriously injured due to pathogenic fungal infection. Simultaneous inoculation with Rhizobium and biocontrol agents provided more growth stimulation compared to either when introduced individually. Field-grown faba beans were inoculated with the diazotroph and representatives of biocontrol strains by two different methods, seed coating and over-head soil. Growth parameters determined were the highest when the legume plant was seed-coated by Rhizobium simultaneously over-head soil inoculated with the bacterial bioagents; this was reported with Bacillus subtilis and Pseudomonas aerugenosa. The significance of combined application of biofertilizer and bioagent to ensure cheap, clean and safe farm products is discussed.     

抗棉叶螨棉花种质川98系的选育

 1979年从陆地棉与海岛棉的杂种后代“抗77”选系的分离群体中，选得抗螨株。历经12代定向选育和抗螨性鉴定，获得了稳定的抗螨种质川98系，并已在国内发放。川98系对棉叶螨具抗生性。与对照73-27相比，在川98植株上取食的叶螨发育缓慢，若螨存活率低，雌螨产卵量减少，单位叶面积螨数仅为73-27的50%。川98降低螨害2级左右，4年不治螨与治螨相比，试验结果不减产。其抗性机制主要与叶面积扩展快、蜡质和几种氨基酸组分含量较高以及其海岛棉遗传背景有关。用川98与陆地棉86-1等杂交，已初步选出抗螨、丰产、优质新品系。