AT毒素胁迫的再生烟草及后代对赤星病的抗性

从4个烤烟品种幼苗心叶叶碟产生的愈伤组织(CA)在含AT毒素的培养基上经两轮筛选,获得的抗毒素CA用于产生了抗病的一次再生植株。用来自抗病性提高50％以上的一次再生株的二代CA产生了抗病的二次再生植株,品种NC89的二次再生抗病植株被称为NC89—TT。获得种子后,NC89—TT二代苗显示出抗毒素损伤、抗病菌侵入、抗病斑扩展的能力,与NC89比,毒素引起的根和叶部病变至少晚8小时、轻64％,病菌孢子侵染率低60％以上,病斑面积减小92％。     

非饱和砂质黏性紫色土崩解特性及MICP加固试验

砂质黏性紫色土遇水极易崩解是导致西南山区土壤侵蚀流失等水土灾害的重要原因,为揭示其崩解规律和机制,改善土体的崩解性,采用自制崩解测量仪对不同初始干密度、含水率及颗粒级配条件下的紫色土进行浸水崩解试验,并从非饱和有效应力角度分析了其崩解演化机制,在此基础上,通过扫描电镜(Scanning Electron Microsc...     

黄瓜3-磷酸甘油醛脱氢酶基因CsGAPDH的克隆及其涝胁迫响应分析

以黄瓜耐涝品系‘早二N’根组织总RNA为模板,运用RT-PCR结合RACE技术,获得了黄瓜3-磷酸甘油醛脱氢酶基因（CsGAPDH）的cDNA全长序列,基因编码区共1011bp,编码336个氨基酸（GenBank登录号HQ156465）。系统进化分析表明：CsGAPDH基因与胡萝卜、葡萄、大豆等双子叶植物同源基因的核苷酸序列相似性均在88%以上,与单子叶植物水稻和玉米同源基因的相似性达86.8%和86%。qRT-PCR表达分析结果表明：CsGAPDH基因快速响应涝胁迫,在涝胁迫2h,该基因在根中表达量达到对照水平的12倍,在涝胁迫12h达到表达高峰,随后表达量呈现逐渐下降趋势;CsGAPDH基因在‘早二N’的根、茎、叶中均有表达,根和叶中原始表达量高于茎,在涝胁迫4h后均诱导表达,根中诱导表达量上调幅度最大,为初始表达量的4倍。CsGAPDH属于黄瓜涝胁迫响应基因,在缓解涝胁迫伤害过程中可能具有重要的调控作用。     

Prohexadione-calcium induces sunflower (Helianthus annuus) resistance against the root parasitic weed Orobanche cumana

Prohexadione-calcium (PHDC) is a plant growth retardant that inhibits gibberellin biosynthesis and transiently alters the spectrum of flavonoids and their phenolic precursors. In this study, root chamber and pot experiments were conducted to evaluate the effects of PHDC on Orobanche cumana seed germination and induction of sunflower resistance to this root parasitic weed. Root chamber experiments indicated that PHDC did not interfere with the progress of Orobanche seed germination, but retarded O. cumana tubercle formation and development. In pot experiments, control of O. cumana by PHDC depended on its dose, method of application and sunflower cultivar. In sunflower cv. HA89, PHDC at 10 mg LS⁻¹ (litre soil) as two drenches or at 1 m m as two foliar sprays significantly reduced the total number and dry matter of O. cumana without influencing flower, leaf and root development. In sunflower cv. Albena, PHDC at 20 and 30 mg LS⁻¹, but not at 10 mg LS⁻¹, as two drenches significantly reduced O. cumana infection. Sunflower cv. HA89 was less susceptible to O. cumana and more inducible by PHDC than sunflower cv. Albena. The biochemical analysis of root extracts revealed a significantly higher accumulation of free phenolics in sunflower cv. HA89 after PHDC soil drench, but not in Albena. No significant lignification was observed after PHDC treatments. The results suggest that PHDC reduces O. cumana infection in sunflower by inducing host resistance, not by directly interfering with the parasite. Free phenolics play an important role in sunflower response to the parasite.     

欧洲山芥植株挥发物对小菜蛾雌成虫选择行为的影响

利用Y型嗅觉仪在实验室内测试了莲座期和开花结籽期欧洲山芥植株挥发物对小菜蛾雌成虫选择行为的影响,以阐明其对小菜蛾雌成虫的引诱作用。结果表明,欧洲山芥两个生长期挥发物对小菜蛾雌成虫具有相似的、较强的引诱作用,小菜蛾首先选择欧洲山芥植株气味源的虫数显著多于首先选择甘蓝植株气味源的虫数,小菜蛾在与欧洲山芥植株相连接的侧臂前臂持续活动的总时间占总观测时间的百分比显著高于与甘蓝植株相连接的一侧(df=1,P<0.05)。     

朱红毛斑蛾和花胸姬蜂对虫害诱导榕树挥发物的触角电位及行为反应

朱红毛斑蛾Phauda flammans是一种寡食性害虫,仅取食小叶榕Ficus concinna和垂叶榕F.benjamina。花胸姬蜂Gotra octocinctus是其幼虫的优势寄生性天敌。研究朱红毛斑蛾及花胸姬蜂对朱红毛斑蛾为害小叶榕和垂叶榕后诱导产生的挥发物的触角电位及行为反应可为实施“推-拉”策略防控朱红毛斑蛾提供基础资料。基于气相色谱-质谱联用(gas chromatography-mass spectrum, GC-MS)和气相色谱-触角电位联用(gas chromatography-electroantennagraphic detection, GC-EAD),从受朱红毛斑蛾幼虫为害的小叶榕和垂叶榕虫害叶挥发物中筛选出对朱红毛斑蛾和花胸姬蜂雌雄成虫有电生理活性的物质,基于Y形嗅觉仪,测定朱红毛斑蛾和花胸姬蜂雌雄成虫对虫害叶挥发物成分的行为反应。结果表明,朱红毛斑蛾为害小叶榕和垂叶榕后,虫害叶中共分离出57种挥发物成分,其中,共有27种能引起朱红毛斑蛾雌雄虫的触角电位反应,在小叶榕和垂叶榕虫害叶片挥发物中同时存在的有11种。其中,两种榕树虫害叶特有的5种挥发物(β-...     

水杨酸诱导车前草抗菌核病研究

车前草苗经水杨酸处理后,接种菌核病菌（Sclerotinia sclerotiorum）。结果表明：5.0mmol/L水杨酸对菌核病菌无抑制作用;0.01,0.1,1.0,3.0,5.0mmol/L五种不同浓度水杨酸处理车前草苗时,0.1mmol/L水杨酸诱导车前草抗菌核病效果比其他浓度要好,其持续时间需要3 d才表现出诱导抗病性。     

Lipopolysaccharides of plant-growth promoting Pseudomonas sp. strain WCS417r induce resistance in carnation to Fusarium wilt

The numbers of diseased plants could significantly be reduced when microconidia ofFusarium oxysporum f. sp.dianthi were inoculated into the stem and viable-, heat-killed cells or purified LPS of the bacteriumPseudomonas sp. strain WCS417r were applied to the roots. Because the competition betweenF. o. dianthi and the bacterium could be excluded, the disease suppression seems to be due to an induced resistance. Accumulation of phytoalexins was found in the stem segments. No accumulation of these compounds was found when the plants were bacterized but noninfected. It is concluded that cell surface components present in the lipopolysaccharides of the bacterium are the inducing factors.Increased peroxidase activity could be measured in root washes and root extracts after only bacterial preparations were added. No significant differences in peroxidase activity were found in stem extracts. The possible role of increased peroxidase activity in suppression of Fusarium wilt in carnation is discussed.     

蚜虫唾液主要成分及其在寄主和害虫互作中的作用

刺吸式害虫唾液里的某些成分通常是植物诱导反应中一些共有的或特异性诱导信号物质。本文综述了蚜虫取食、唾液的主要成分和取食诱发的植物防御信号传导途径,例如水杨酸途径、茉莉酸/乙烯途径,以及唾液诱导使植物防御因子上调效应的分子检测方法;同时还展望了蚜虫唾液研究的应用前景。     

番茄青枯病抑病土壤作用机制研究

研究表明,宜春市番茄青枯病抑病土壤(白泥土)作用的主导因素是该类土壤碳酸钙含量高和土壤pH值偏碱,同时,与该类土壤粘腻以及对番茄青枯病的田间蔓延的阻抑作用也有密切的关系,而与土壤中其他微生物无关。研究还表明,白泥土和碳酸钙能抑制番茄青枯病菌及诱导番茄抗青枯病。