Analysis of genetic diversity among Macrophomina phaseolina (Tassi) Goid. isolates from Euro-Asian countries

Journal of Plant Diseases and Protection - The study assessed the genetic variability among Macrophomina phaseolina (Tassi) Goid. isolates originating from six different countries (Turkey,...     

Effects of alternative pesticides on greenhouse whitefly in protected cultivation

The greenhouse trials were conducted to determine the efficacy of environmentally safe insecticides/fungicides with physical mode of action [Agri-50E (propylene glycol alginate, hydrated) and SB Plant Invigorator] against Trialeurodes vaporariorum (Westwood). The efficacy of Agri-50E on adults and nymphs (first, second, third, and fourth instars) was compared to the commercially available standard Boxer 200 SL (imidacloprid) and an untreated control on greenhouse-grown poinsettia. Insecticides were applied by foliar spraying, Agri-50E (2 or 3 ml/l) two times and Boxer 200 SL (1 ml/l) once. Three and 7 days after first application (DAFA), imidacloprid was more effective than both concentrations of Agri-50E in controlling T. vaporariorum adults, whereas 10 DAFA there were no differences between insecticides. Twelve DAFA, imidacloprid was more effective than Agri-50E in controlling first, second and third instars and after 19 days in controlling second, third, and fourth instars. The results obtained from the poinsettia study, indicated that Agri-50E (2 or 3 ml/l) is successful in controlling T. vaporariorum adults and moderately effective against T. vaporariorum immature stages. In the second experiment, the efficacy of Agri-50E on adults was compared to SB Plant Invigorator (SBPI), the standard treatment Calypso 480 SC (thiacloprid), and an untreated control on greenhouse-grown tomato. Agri-50E (3 ml/l) and SBPI (2 ml/l) were applied four times while Calypso 480 SC (0.4 ml/l) was applied twice. The results obtained from tomato study showed that SBPI was the most effective insecticide against T. vaporariorum adults, followed by Agri-50E and Calypso 480 EC. Beside the ecological benefits, the alternative insecticides Agri-50E and SBPI might have an important role to play in future pest management programs.     

Invasive and quarantine pests in forests in Slovakia1

Biological invasions of insects, plants, and fungal pest species often cause substantial disturbance to forest ecosystems and as well as severe socioeconomic impacts. Central Europe acts as a ‘bridge’ between Western and Eastern Europe both ecologically and as an important transit corridor for people. Human activity, including the movement of material goods, increases the risk of invasions. Some species introduced in the past have been established, becoming common and causing serious problems (such as Dreyfusia nordmannianae or Hyphantria cunea). The status, importance and spatial distribution in Slovakia of seven different forest pests recently introduced into Slovak forest ecosystems (Cameraria ohridella, Coleotechnites piceaella, Cryphonectria parasitica, Dothistroma septospora, Ips duplicatus, Parectopa robiniella, Phyllonorycter robiniellus) as well as two others not yet recorded in Slovakia (Anoplophora glabripennis, Phytophthora spp.) is discussed.     

Note: Current status ofBemisia tabaci in Coastal Croatia

Bemisia tabaci was first noted in Croatia in 2000, when it was identified in Split County, Dalmatia. Thirty-one plant species were identified as hosts of this pest in the central Adriatic region during 2001–2002. Four adult populations were analyzed at CIDA (Spain) by comparing a fragment of the COI gene of the mitochondrial DNA, and by examining a single microsatellitelocus. The results indicated a predominance of the Q biotype. The population dynamics ofB. tabaci was examined in outdoor conditions by observing populations fromIpomoea purpurea in 2002. The pest population appeared at the beginning of June and increased in number until its decline at the beginning of October. http://www.phytoparasitica.org posting Dec. 20, 2004.     

基于SCoT标记分析西藏白菜型黄籽油菜遗传多样性

为研究西藏白菜型黄籽油菜种质资源的遗传多样性，提高其育种利用效率。采用SCoT标记方法，对30份白菜型黄籽油菜种质资源进行遗传多样性分析，并结合生物学特性信息进行综合分析。通过对50条SCoT标记引物的筛选，获得24条重复性好、多态性高、遗传信息丰富的引物，并对参试种质资源进行PCR扩增，共获得214个DNA位点，其中具有多态性的位点有182个，平均多态性位点百分率为87.33%。应用NTSYSPc 2.10e软件分析得到，供试种质资源的相似系数在0.473～0.930之间，进行非加权组平均法（UPGMA）聚类分析得出树状图，在相似系数为0.797时，可将30份材料完全区分成5组。结果表明，西藏白菜型黄籽油菜之间的遗传多样性较为丰富，并综合生物学特性和分子水平试验研究，发现塔巴寺黄籽油菜某些性状与芥菜型油菜相似，初步认为塔巴寺黄籽油菜可能是与芥菜型油菜杂交的后代或者本身就携带类似芥菜型油菜的隐性基因，此假设可在后期分子水平实验中进一步论证。     

外源二乙基二硫代氨基甲酸钠对初花期淹水大豆根系氮代谢的影响

为明确二乙基二硫代氨基甲酸钠（DDTC）对淹水胁迫下大豆根系氮代谢的调控作用,采用盆栽试验,以大豆品种徐豆18（敏感）和南农1138-2（耐涝）为试验材料,在大豆初花期（R1）叶面喷施蒸馏水或DDTC,喷施1 d后进行淹水胁迫8 d（水面淹至大豆子叶节部位）,研究DDTC对花期淹水大豆根系活力、根系含氮化合物以及氮代谢酶活性的影响。结果表明：淹水胁迫下,与徐豆18相比,南农1138-2根系活力、固氮能力以及根系含氮化合物输出能力的下降幅度较小,根系中铵态氮（NH4+-N）含量增加幅度较小,而根系中硝酸还原酶（NR）和谷氨酰胺合酶（GS）活性、硝态氮（NO3--N）和游离氨基酸（FAA）含量增加幅度较大。DDTC处理提高了淹水胁迫下根系活力和根系干质量,进而有利于缓解淹水胁迫对大豆产量的抑制;增加了根系中NR、GS活性,NO3--N、FAA、可溶性蛋白含量,并降低了NH4+-N含量,从而增强了根系对氮素的吸收、同化能力;抑制了根瘤干物质重和根瘤固氮酶活性下降,进而提高了淹水胁迫下大豆固氮能力;DDTC处理也能缓解淹水胁迫下伤流液中NO3--N、FAA总量下降,表明DDTC处理促进了根系中含氮化合物向地上部转运。总之,淹水胁迫下,外源DDTC能够通过调控根系氮代谢减轻淹水胁迫对大豆植株的伤害。     

地蚜灵不同施用方式对油菜蚜虫的防效及对产量和农药残留的影响

为明确地蚜灵的灭蚜效果,在油菜田间采用播种沟施药和土表撒施的方式研究播种期施不同药量对整个生育期蚜虫的防控效果,调查其安全性和对油菜的增产作用。结果表明,几种施用方式和用量中,覆土前撒施地蚜灵900g·hm-2对油菜蚜虫的防控效果较好,整个生育期防效在90%以上,成熟期防效仍达88.6%。施药的各处理与对照相比,油菜单株角果数、角粒数、千粒重、产量均有显著提高,增产幅度在13.7%～25.8%。所有处理中,用药量越大,防治效果越好,产量越高;用药量相同前提下,覆土前表面撒施的防治效果较好。各处理显著提高油菜籽粒的含油量和油酸含量,且菜籽中没有检测出地蚜灵的农药残留。综合防效来看,覆土前撒施地蚜灵900g·hm-2的方法既简化又高效,是一种极具有推广应用价值的环保型油菜蚜虫防控新技术。     

普通玉米种植甜玉米抵御白星花金龟为害的初步尝试

2007—2009年,采用在普通玉米田(先玉335)中混种少量甜玉米(吉甜6号)作为诱虫植物并于灌浆期对其不处理或定期(07-25,08-09,08-23)于穗上喷施辛硫磷乳剂(40％,15 mL)等措施,抵御白星花金龟为害。试验结果表明：未用化学药剂处理的混种田内,普通玉米平均穗损失值(0.39)低于对照田普通玉米(1.03),甜玉米平均穗损失值(1.63)高于对照田甜玉米(1.50)。以14 d为间隔期,喷施辛硫磷于甜玉米穗上,混作田内的普通玉米平均穗损失值进一步降低。据此得出初步结论:用甜玉米作为诱虫植物,抵御白星花金龟对普通玉米的为害切实可行。     

环境因素和嫁接方法对甘蓝型油菜幼苗嫁接成功率的影响

以甘蓝型油菜品种中双11为相互嫁接材料，利用正交试验和二次正交回归试验，解析保湿、遮光处理、光照时长、子叶去留、温度、相对空气湿度等环境因素对甘蓝型油菜苗期嫁接的影响；对3个不同时期的幼苗分别采用平接、斜接、插接、侧接和舌接法进行嫁接，综合评价各时期的最佳嫁接方法。结果表明，保湿处理对幼苗期嫁接成功率影响最显著，其次是遮光处理；光照时长和子叶去留影响较小。温度和湿度二次正交回归试验分析表明，缓冲期嫁接伤口愈合最适宜温度为24.4℃，相对空气湿度为88%左右；高空气湿度下，接穗在伤口愈合处极易生长不定根，适当降低空气湿度能抑制不定根的生长。10d的幼苗进行嫁接，5种嫁接方法成功率均达到85%以上；20d的幼苗用舌接法嫁接成功率达到93.3%，而平接和斜接法只有56.7%和46.7%；40d的幼苗在5种嫁接方法下成功率均显著下降，舌接、插接和侧接成功率分别为45%、35%和23.3%，而平接和斜接仅有13.3%和10%。 存、快速繁育，在提高果树和农作物产量、抗逆和抗 病能力以及改良作物品质等方面具有重要的应用价 值［１～４］。嫁接成功率是衡量嫁接效率的重要指标， 不仅受到接穗和砧木亲和力等自身因素影响，同时 也受环境因素和嫁接技术等外界因素控制。拟南芥 （Ａｒａｂｉｄｏｐｓｉｓｔｈａｌｉａｎａ）嫁接研究中，Ｔｓｕｋａｙａ等［５］利 用ａｃｌ１（ａｃａｕｌｉｓ１）突变体与野生型进行花序嫁接，采 用了楔形嫁接法将花序作为接穗嫁接到砧木的茎 上。随后Ｒｈｅｅ等［６］对Ｔｓｕｋａｙａ的方法进行改进，在 最佳生长周期进行楔形嫁接成活率可达８７％。拟 南芥根茎嫁接中，Ｔｕｒｎｂｕｌｌ等［８］发现“Ｙ”型嫁接成 功率稍高于水平嫁接和楔形嫁接。Ｈｕａｎｇ和Ｙｕ［９］ 等利用针头固定嫁接技术，改善了拟南芥的嫁接环 境，大幅度提高了拟南芥的嫁接效率。Ｍａｒｓｃｈ－ Ｍａｒｔíｎｅｚ［１０］从光照时间、子叶数目等方面系统地分 析了外界因素对嫁接成活率的影响，发现短日照有 利于嫁接植株伤口的愈合，去除子叶更有利于嫁接 体存活；西瓜（Ｃｉｔｒｕｌｌｕｓｌａｎａｔｕｓ）嫁接中也发现了相 似的结果［１１］。可乐果（Ｃｏｌａａｃｕｍｉｎａｔａ）嫁接中发 现，相同时期的接穗嫁接到不同苗龄期砧木上，低苗 龄砧木成功率高于高苗龄砧木［１２］。 油菜嫁接研究中，Ｆｉｌｅｋ等［１３］用插接法把未春 化的接穗嫁接到春化的砧木上，电流刺激试验记录 开花百分比，结果发现极性电流能促进短日照下的 开花。官春云等［１４］用插接法对不同油菜品种进行 嫁接，嫁接成功率达到５０％以上。Ｏｓｔｅｎｄｏｒｐ等［１５］ 用平接法对生长６ｄ的甘蓝型油菜幼苗嫁接发现，除 去子叶的幼苗在长日照下有更高的成功率。耿建明 等［１６］对不同品种甘蓝型油菜幼苗嫁接发现，在空气 湿度为９０％的保湿遮光处理下，嫁接苗具有较高的 成活率。在不同甘蓝型油菜基因型硼效率差异机制 研究中，郭丽丽对传统的插接法进行改进，发现改进 后的嫁接方法在幼苗期嫁接成功率明显提高［１７］。 总结前人研究发现，环境因素和嫁接方法对嫁 接