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1.
海南草地贪夜蛾寄生蜂调查与基础生物学观察 总被引：1，自引：0，他引：1
海南省是我国草地贪夜蛾入侵地之一,为了掌握草地贪夜蛾在海南的发生与防控情况,2019年4—7月,中国热带农业科学院环境与植物保护研究所专家对海南省18个市县主要玉米种植区的草地贪夜蛾天敌开展了实地调查。本研究将调查区采集到的被寄生卵块、幼虫和蛹置于实验室条件下饲养观察,共发现5种寄生蜂天敌,其中卵寄生蜂为夜蛾黑卵蜂和螟黄赤眼蜂,幼虫寄生蜂为淡足侧沟茧蜂,蛹寄生蜂为霍氏啮小蜂,卵-幼虫寄生蜂为台湾甲腹茧蜂,并报道了这5种寄生蜂的主要鉴别特征和基本生物学特性。掌握海南本地草地贪夜蛾寄生蜂天敌的种类,初步探究了其对这种外来入侵害虫的自然控制作用,为筛选防治草地贪夜蛾的优势天敌提供参考。 相似文献
2.
A. Minuto M.L. Gullino F. Lamberti T. D&#x;Addabbo E. Tescari H. Ajwa A. Garibaldi 《Crop Protection》2006,25(12):1244-1252
A mixture of 1,3-dicloropropene 60.5% w/w and chloropicrin 33.3% w/w (Telone C35 EC) may be registered in Italy for soil drip fumigation. Five experiments on greenhouse tomatoes in Northern, Central and Southern Italy compared the effectiveness of this mixture in comparison with methyl bromide to find the optimum application rate in soils infested by Fusarium oxysporum f.sp. lycopersici, F. oxysporum f.sp. radicis lycopersici, Sclerotium rolfsii, Meloidogyne javanica and M. incognita. Its efficacy against F. oxysporum f.sp. radicis lycopersici and M. incognita was confirmed when applied to soils at 100, 200, 300 and 400 l ha−1 (132.4, 268.4, 402.6 and 536.8 kg ha−1) under gas-tight films with 15–45 mm of application water (900–1200 mg Telone C35 EC l−1). In sandy soils, with slight F. radicis lycopersici infections and with heavy nematode (M. incognita) attacks, the mixture, drip applied at 900 mg l−1 during late summer (fumigation: late summer; transplant: late-summer/autumn; last harvest: early spring), performed well up to 132.4 kg ha−1 (100 l ha−1). In sandy loam soils with slight F. radicis lycopersici infections and severe infections of F. lycopersici and galling nematodes (M. javanica), 268.4 kg ha−1 (200 l ha−1) of the mixture applied at 900 mg l−1 as a drip provided yields similar to those of methyl bromide treated plots both in spring and summer cycles. In sandy loam soils, the diseases (F. lycopersici, F. radicis lycopersici) were controlled at rates 268.4 kg ha−1 (containing 90 kg ha−1 of chloropicrin), but the mixture was ineffective against Sclerotium rolfsii occasionally observed in sandy loam soils. In both sandy and sandy loam soils, no significant relationships were found between the rates of mixture applied (132.4, 268.4, 402.6 and 536.8 kg ha−1) and the degree of nematode infestation. 相似文献
3.
超高压辅助提取技术是一种天然产物新型绿色高效提取技术,在保证提取效率的同时能最大限度保持天然产物的生物活性。为探究超高压辅助提取技术对辣木籽多糖的提取效果及其抗氧化活性的影响,本研究以辣木籽为原料,通过超高压辅助提取技术提取辣木籽中的水溶性多糖,以多糖得率为考察指标,以提取压力、提取时间、料液比、粉碎度作为单因素,在单因素试验基础上,采用正交试验设计方法优化辣木籽多糖的超高压辅助提取工艺,并通过测定总抗氧化能力、清除DPPH自由基（DPPH•）和羟自由基（•OH）的能力来分析辣木籽水溶性多糖的抗氧化活性。结果表明,辣木籽多糖最佳的超高压辅助提取工艺条件为：提取压力100 MPa、保压时间6 min、料液比（g/mL）1:15、粉碎度100目筛,在最佳提取工艺条件下辣木籽多糖最大提取得率为0.346%;在测试范围内辣木籽多糖清除DPPH自由基能力随多糖浓度的增加而增加,并有较好的线性关系,清除率达到50%时对应的浓度（IC50）为0.0439 g/L,但是其抗氧化能力低于相同浓度的Vc,在测试范围内清除羟自由基能力也随辣木籽多糖浓度的增加而增加,也有较好的线性关系,IC50为0.1666 g/L,其抗氧化能力与同浓度的Vc较接近,辣木籽多糖的总抗氧化能力为0.0482 mmol/L（以硫酸亚铁的当量浓度表示）。与热水提取方法相比,超高压辅助提取方法能够缩短提取时间,提取温度大大降低,提取效率显著提高;而且提取的辣木籽水溶性多糖具有较好的抗氧化能力,可以作为天然抗氧化剂进行开发利用。本研究结果可为天然抗氧化剂的开发、辣木资源的综合开发及高值化利用提供技术支持和参考。 相似文献
4.
石碌含笑（Michelia shiluensis）是海南特有树种和国家Ⅱ级濒危保护植物,野外仅见分布于吊罗山、鹦哥岭、五指山等海南中南部山区。吊罗山是石碌含笑最集中的自然分布区,开展吊罗山石碌含笑群落木本植物种间联结性研究,有助于了解该树种在群落中的地位与作用,为制定合理的就地保护措施提供参考。本研究基于2×2列联表,综合运用χ2检验、Pearson相关系数检验和Spearman秩相关系数检验对吊罗山石碌含笑与群落内其他伴生种的种间关系进行了探讨分析。结果表明：石碌含笑种群与灌木层的正关联比乔木层多;石碌含笑与群落内绝大多数植物的种间联结不显著,种间关系表现出总体比较松散的趋势,种群间相互独立的趋势明显,乔木层和灌木层总体上与石碌含笑正关联物种多于负关联物种数,表明群落的发展朝着有益于石碌含笑种群发育的趋势。研究结果对制定合理的就地保护措施和恢复计划具有参考价值。 相似文献
5.
Marjorie A. Hoy 《Crop Protection》2000,19(8-10):657-664
David Rosen was a scientist, professor, administrator, philosopher, organizer, family man, and friend to many. He made numerous and remarkable contributions to biological control in citrus. Much of his research was on the biosystematics of Aphytis parasitoids, but he also held strong convictions about the importance of biological control in citrus integrated pest management (IPM), and carried out research on genetic improvement of parasitoids. David was the first incumbent of the Vigevani Chair of Agriculture and Professor of Entomology at the Faculty of Agricultural, Food and Environmental Quality Sciences at the Rehovot campus of the Hebrew University of Jerusalem. David served as an organizer of the XIV International Plant Protection Congress in Jerusalem, Israel, and his imprint on the congress was evident despite his absence. In addition to reviewing David's scientific contributions, I present an overview of the challenges facing biological control in the USA, including many that concerned David: increased scrutiny from regulatory agencies regarding the effects of natural enemies on nontarget species, loss of taxonomic experts, concerns about the accidental introduction of plant pathogens with the importation of natural enemies of insect vectors, and challenges to the tradition of international cooperation. If the increased demand for biological control is to be met in 21st century agricultural IPM programs, several scientific, social, and legal issues must be resolved. 相似文献
6.
镁营养对苦瓜生长发育及生理代谢的影响 总被引：2，自引：0，他引：2
采用砂培的方式,以‘翠玉’苦瓜（Momordica charantia）品种为试验材料,研究不同镁素浓度（0、20、40、80、160 mg/L）处理下对苦瓜生长特性（叶片和根系形态、光合色素含量、碳氮代谢、生物量积累）和生理响应（渗透调节、膜伤害和抗氧化）的影响。结果表明：镁浓度为20~80 mg/L时可以降低苦瓜叶片膜伤害,增加叶片中可溶性糖、可溶性蛋白质、光合色素和谷胱甘肽（GSH）含量,增强叶片抗氧化酶活性,包括超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）和单脱氢抗坏血酸还原酶（DHAR）,降低叶片丙二醛（MDA）、脯氨酸（Pro）、过氧化氢（H2O2）含量和超氧阴离子（O2-）的产生速率及细胞膜透性,促进根系活力、光合作用和生物量积累。其中,40 mg/L镁处理对苦瓜的生长发育增效最明显,而缺镁（0 mg/L）和过量镁（160 mg/L）胁迫下,苦瓜叶片产生膜脂过氧化伤害、主根变短、侧根减少,苦瓜地上部和地下部生长均受到明显抑制,缺镁比镁过量的抑制作用更强。综上所述,缺镁和过量镁抑制苦瓜生长,而适量增施镁可有效提高苦瓜的生理活性,增强苦瓜抗逆性,促进苦瓜生长,40 mg/L为苦瓜栽培最适宜施镁浓度。 相似文献
7.
The widespread and intensive use of conventional pesticides, particularly insecticides, presents a major risk to natural enemies of target pests, as well as to the environment in general. The aim of this study was to investigate the differential intrinsic toxicity of insecticides to two key pests of crucifers, Plutella xylostella and Myzus persicae and their respective hymenopteran parasitoids, Cotesia vestalis and Aphidius colemani. Such knowledge can help inform effective integration of insecticides and biological control in IPM systems. Three insecticides generally regarded as being compatible with natural enemies (abamectin, spinosad and indoxacarb) and one compound regarded as harmful to natural enemies (lambda-cyhalothrin) were examined. A comparative measure of the intrinsic toxicity of fresh deposits of insecticides on Chinese cabbage leaf discs was determined for both pest and parasitoids species after exposure to insecticide for 24 h and 120 h, and after 24 h exposure to insecticide plus 96 h on untreated leaf discs. Differences in the susceptibility of pests and parasitoids to different insecticides were marked for P. xylostella and C. vestalis, LC50 values being significantly lower for the pest species. Such differences were not observed for M. persicae and A. colemani. There was a direct relationship between dose, exposure time and toxicity for all insecticides tested. All insecticides tested showed lower toxicity to both parasitoids compared with P. xylostella, which suggests that for this pest species side-effects on parasitoids can be minimised through IPM practices that reduce exposure time to such non-target organisms. 相似文献
8.
The beneficial parasitoid Asecodes hispinarum Bouček plays an important role in integrated pest management (IPM) of the coconut leaf beetle, Brontispa longissima (Gestro), in China. A. hispinarum females parasitize 3rd to 4th instars B. longissima larvae. Hatched parasitoid larvae develop within the host, and parasitoid adults emerge through holes that they chew through the cuticle of the host. Although chemicals serve as the main short term control agents, the compatibility of biological and chemical control has never been investigated for this system. This study examined the responses of immature and adult B. longissima and its larval parasitoid A. hispinarum to avermectin and acetamiprid. Avermectin caused complete mortality of 2nd to 4th instar larvae, and of adults of B. longissima at 10, 15 and 2 d after treatment, respectively. However, 26.7% of the 2nd instar larvae, 55.3% of the 4th instar larvae, and 74%, of adult B. longissima were still alive 40 d after acetamiprid application. Following avermectin exposure, 17.5%, 9.2% and 23% of mummified B. longissima larvae contained viable adult parasitoids for the parasitoid egg, larva and pupa treatments, respectively, and the numbers of dead parasitoids per mummy were 3.3, 7.2 and 13.3 for the egg, larva and adult treatments, respectively. However, for acetamiprid treatment, 70–75.9% of mummified B. longissima larvae contained viable adult parasitoids in all three stage treatments, and the number of dead parasitoids per mummy was 2.8, 2 and 3.4 in egg, larva and adult treatments, respectively. This study showed that a sublethal dose of avermectin is more toxic than acetamiprid to B. longissima and A. hispinarum. Therefore, direct contact of the parasitoid with avermectin should be avoided when this insecticide is used to control B. longissima. 相似文献
9.
【目的】由稻瘟病菌（Magnaporthe oryzae）引起的稻瘟病和由水稻黄单胞菌（Xanthomonas oryzae pv. oryzae，Xoo）引起的白叶枯病严重影响水稻的产量和品质。创制转OsLOX10基因水稻材料，进行稻瘟菌和白叶枯菌的抗病性分析，有助于揭示其调控水稻对稻瘟病和白叶枯病的抗性机制。【方法】采用CRISPR/Cas9系统构建OsLOX10的敲除载体，利用限制性内切酶XcmⅠ线性化pCXUN-HA，TA连接构建OsLOX10的过表达载体，遗传转化获得OsLOX10转基因水稻，筛选过表达株系和纯合敲除株系进行真菌和细菌的抗病性分析。在稻瘟菌（Guy11）侵染水稻后，对水杨酸（salicylic acid，SA）、茉莉酸（jasmonic acid，JA）途径的标志基因进行qRT-PCR分析;在几丁质（chitin）和flg22诱导下，观测水稻活性氧（reactive oxygen species，ROS）的暴发情况。【结果】 qRT-PCR分析表明，接种稻瘟菌和白叶枯菌24 h后，OsLOX10表达量上调;OsLOX10的纯合敲除和过表达水稻转基因株系接种稻瘟病菌Guy11孢子悬浮液，与野生型（日本晴）相比，OsLOX10敲除株系更易感病，过表达株系则无典型的病斑症状;接种 6、12、24和36 h时，3个病程相关蛋白基因OsPBZ1、OsPR1a、OsPR1b和SA通路基因OsPAL1，以及JA合成通路上的2个基因OsAOS2、OsLOX5的转录水平在敲除转基因株系中显著下调，而在过表达转基因株系中显著上调。对转OsLOX10基因水稻接种白叶枯菌（PXO99A），发现敲除OsLOX10的转基因水稻对白叶枯菌更易感病。qRT-PCR分析OsPR1b和OsPAL1以及JA合成通路上的3个基因OsAOS2、OsAOC和OsJAZ在OsLOX10过表达基因水稻中表达量明显上调，而在敲除OsLOX10的转基因水稻中却保持在较低水平，在接种7 d后表现出显著性差异。在几丁质和flg22诱导下，OsLOX10敲除株系的ROS水平显著性降低，而且在几丁质诱导下，ROS的起峰时间推迟。【结论】稻瘟病菌和白叶枯病菌能够诱导OsLOX10的表达，OsLOX10通过病原菌分子模式触发的免疫途径（PTI）参与抗病反应，其在水稻抵御稻瘟病和白叶枯病中起着正调控作用。同时，OsLOX10可能通过调节SA和JA介导的信号通路来正调控水稻对稻瘟病和白叶枯病的抗性。 相似文献
10.
为明确桑树主要害虫桑螟的天敌寄生蜂资源及其寄生特性并利用生物防治措施有效控制桑螟的危害,对海南主要桑园桑螟寄生蜂进行了系统调查和研究。结果表明,海南桑螟天敌寄生蜂主要有5种,分别为桑螟绒茧蜂Apanteles heterusiae Wilkinson、食心虫白茧蜂Phanerotoma planifrons Nees、红铃虫甲腹茧蜂Chelonus pectinophorae Cushman、菲岛长距茧蜂Macrocentrus philippinensis Ashmead和广大腿小蜂Brachymeria lasus Walker。其中,桑螟绒茧蜂为优势种,田间寄生率高达63.24%,1头桑螟幼虫可出蜂3~16头;其他4种寄生蜂均为单寄生,田间平均寄生率依次为9.15%、6.21%、5.62%和5.24%。室内寄生特性研究发现,桑螟绒茧蜂对桑螟龄期和密度具有选择性,主要寄生1龄和2龄桑螟幼虫,偶尔寄生3龄幼虫,仅在1龄桑螟幼虫密度为9和2龄密度为8头时寄生率最高,且出蜂量最大。待被寄生桑螟幼虫发育至5龄时从桑螟体内啮出,并在5~7 h内结茧化蛹,啮出幼虫可全部化蛹,4~5 d后羽化,羽化率为33.33%~ 100%,性比为0~87.50%,成蜂寿命为1~3 d,多为2 d,雄蜂寿命略短于雌蜂。未观察到桑螟绒茧蜂寄生家蚕。研究为桑螟绒茧蜂的规模化繁育和利用提供前提。 相似文献
11.
本研究以广西桂林柑桔园黑刺粉虱（Aleurocanthus spiniferus）为对象,采用田间调查该粉虱卵、若虫、蛹和成虫的方法,研究了该粉虱的种群消长规律。结果表明：广西桂林柑桔园每年3月中旬—12月上旬的气温可满足黑刺粉虱的生长发育需要,2015—2017年间黑刺粉虱种群变动较大,黑刺粉虱卵至蛹全年发生高峰在5月中旬—7月上旬,其次在8月下旬—9月上旬;而成虫全年发生高峰在5月上旬,其次则在9月上中旬。本研究表明每年5—9月是桂林柑桔园黑刺粉虱自然种群增长较快的时期,生产上应用密切关注这一时期的该粉虱种群动态,并根据其危害情况及时采取必要的防治措施。 相似文献
12.
The orange wheat blossom midge, S. mosellana (Gehin) (Diptera: Cecidomyiidae), a global pest of wheat (Tritium aestivum L.), has recently invaded Montana's Golden Triangle, an important wheat producing region. Unchecked, S. mosellana populations can quickly grow to damaging levels. In this study, we document the prevalence of S. mosellana and its main natural enemy, Macroglenes penetrans (Hymenoptera: Pteromalidae), in this newly invaded area of Montana, and compared the effects of irrigated versus dryland cropping systems on S. mosellana and its parasitoid. Different approaches to monitoring S. mosellana populations were examined, including pheromone traps for adults, collection of larvae from wheat heads, and overwinter sampling of soil to measure the levels of larvae and cocoons. Adults of the M. penetrans were surveyed through daily sweep net sampling. This study demonstrated that the emergence of M. penetrans was usually well synchronized with emergence of S. mosellana as the emergence of parasitoids occurred shortly after the pest with the highest peak (90%) at 26 June and 14 July, 2015, respectively. Irrespective of sampling techniques; pheromone traps or soil sampling, no significant difference was observed in population of S. mosellana between irrigated and dryland cropping systems. In contrary, cropping systems played a significant role in the abundance of parasitoids since the irrigated fields had significantly higher population of parasitoids (five times on an average) compared to dryland cropping system. The possible implications of these findings in monitoring of S. mosellane and the establishment of M. penetrans are discussed. 相似文献
13.
辣木的营养价值及其加工展望 总被引：1，自引：0，他引：1
辣木广泛种植于热带和亚热带地区,耐受干旱和霜冻等恶劣天气,具有较强的生长抗逆性。辣木含有丰富的营养成分和植物化学成分,具有较强的抗氧化、抗炎等生理功效,极具开发潜能。目前,辣木的研究主要集中在辣木叶和辣木籽,其加工也主要通过添加辣木叶粉或辣木籽油等作为营养补充剂制备产品。本文主要综述了辣木各部位的营养价值、提取物的生理功效以及在食品和日化产品行业的加工现状,为辣木加工基础理论研究提供思路,为辣木的深层次加工提供参考依据,推动辣木产业发展。 相似文献
14.
《Journal of Crop Improvement》2013,27(1):49-61
Summary Populations of insect pests sometimes increase beyond the economic threshold to become serious problems in crop production. However, their populations are usually maintained below the economic injury level by natural predator insects and parasites. Living bodies often develop a degree of immunity against pest invasion, such as macrophages in the human body. In this case, macrophages reproduce in the human body at the expense of blood and body fluid, but are suppressed below the level of illness to the human body. This is analogous to crops, which have developed defense mechanism in the biotic community against pests by means of natural enemies and provided immunity in a total system. However, natural enemies, parasites and predators, must be maintained themselves with little compensation or support from the agroecosystem. Some years ago I proposed a model “reproduction curve with two equilibrium points” to describe the fluctuation of insect populations (Takahashi, 1964). The lower equilibrium point in the model can be regarded as a latent period and the higher one as the outbreak level. This model is based on the S-shaped functional response curve of predator to prey density and is applicable in a biotic community where polyphagous predators predominate. To ensure stable populations of natural enemies in the biotic community, it is necessary to maintain their food supply in the field. The populations of monopha-gous predators, such as parasitoids, fluctuate in response to prey or host populations sometimes inducing dramatic increases in pest populations above the economic injury level. On the other hand, polyphagous predators can utilize ordinary organisms as alternate food sources and keep their population stable even when a pest population (i.e., their target food) decreases to low level. This model will be discussed with respect to the diversity of a biotic community. 相似文献
15.
Conservation biological control, which fosters the optimal use of indigenous natural enemies, is a promising way for reducing pesticide reliance in horticultural systems. A two-year field survey was conducted in the main cabbage-producing area in Senegal (Niayes) to assess the potential of indigenous parasitoids to control populations of Plutella xylostella (Lepidoptera, Plutellidae). Results showed an overall low level of parasitism (11.7%) which was independent of host abundance, but was highly variable among fields (0–50%). Parasitism was predominant in the late part of dry season. Insecticide use, mostly relying on broad-spectrum insecticides, had a negative effect on the overall parasitism rate. Observations conducted throughout the cabbage crop cycle showed that parasitism unexpectedly decreased with crop aging (from 41 to 60 days post transplanting), likely due to repeated insecticide applications. Four main parasitoid species including Oomyzus sokolowskii (Kurdjumov) (Eulophidae) (48.8%), Apanteles litae Nixon (Braconidae) (32.5%), Brachymeria sp. (Chalcididae) (11.3%), and Cotesia vestalis Haliday (Braconidae) (7.3%) were identified. Parasitism due to O. sokolowskii was greater during the first part of the dry season whereas parasitism due to A. litae was greater during the second part of the dry season. Parasitism due to Brachymeria sp. was not affected by time of season but was greater in the Centre and North than in the South of Niayes. Parasitism due to C. vestalis was equal in the three zones but was higher in the late part of the dry season. The diversity of parasitoids was constant across zones but was greater during the second part of dry season. A positive relationship between diversity (Shannon diversity index H′) and parasitism rate was observed, suggesting a positive effect of parasitoid diversity on natural pest control. Parasitoids have a promising role to play as biocontrol agents of P. xylostella populations in Senegal, provided significant changes to current insecticide use are made. Better knowledge of their resource requirements including crop and non-crop habitats, and provision of these in and around crops is also needed. 相似文献
16.
The diamondback moth (DBM), Plutella xylostella (L.), remains a major pest of brassica crops worldwide. DBM has been estimated globally to cost US$ 1 billion in direct losses and control costs. Chemical control of this pest remains difficult due to the rapid development of resistance to insecticides and to their effect on natural enemies. These problems are especially severe in South Asia and Africa where lack of knowledge, limited access to newer and safer insecticides, and a favourable climate result in DBM remaining a serious year-round pest which substantially increases the cost and uncertainty of crop production. Despite these problems, application of synthetic insecticides remains overwhelmingly the most common control strategy. Biologically-based efforts to control DBM in Africa and Asia have focused strongly on parasitoid introductions. However, despite the identification and deployment of promising parasitoids in many regions, these efforts have had limited impact, often because farmers continue early-season spraying of broad-spectrum insecticides that are lethal to parasitoids and thus exacerbate DBM outbreaks. A significant driver for this pattern of insecticide use is the presence of aphids and other pests whose appearance initiates inappropriate spraying. Despite often extensive training of producers in farmer field schools, many growers seem loath to discard calendar or prophylactic spraying of insecticides. The introduction of an IPM technology that could replace the use of broad-spectrum insecticides for DBM and other key Lepidoptera is crucial if the benefits of parasitoid introduction are to be fully realised. The deployment of DBM-resistant brassicas expressing proteins from Bacillus thuringiensis could help to break this cycle of insecticide misuse and crop loss, but their deployment should be part of an integrated pest management (IPM) package, which recognises the constraints of farmers while addressing the requirement to control other Lepidoptera, aphids and other secondary pests. 相似文献
17.
【目的】检测枯草芽孢杆菌JN005产生的胞外抗菌物质的稳定性和对稻瘟病菌的生物活性,及其对水稻叶瘟的防治效果。【方法】通过不同培养基检测枯草芽孢杆菌JN005产生的抑菌物质,结合平板对峙法、光学显微镜观察、室内离体和活体接种来检测JN005菌株胞外抗菌物质对稻瘟病菌拮抗活性和对水稻叶瘟防治效果。【结果】枯草芽孢杆菌JN005能分泌蛋白酶、纤维素酶、淀粉酶和β-1, 3-葡聚糖酶,其胞外抗菌物质对稻瘟病菌生长具有抑制作用。胞外抗稻瘟病菌物质在0℃~100℃和pH 2~12范围内活性较为稳定,且经蛋白酶K处理后不影响其活性,紫外照射12 h以及4℃保存3个月仍有活性。胞外抗菌物质能引起稻瘟病菌菌丝形态畸变,并抑制分生孢子的萌发。室内湘晚籼12号稻瘟病离体叶片接种表明,先用100倍胞外抗菌物质稀释液处理水稻叶片,24 h后接种稻瘟病菌分生孢子悬浮液(1×105个/mL),其叶瘟发病率为34.07%,效果接近稀释500倍的40%稻瘟灵EC;而先接种稻瘟病菌分生孢子悬浮液,24 h后用100倍胞外抗菌物质稀释液处理,其发病率为38.52%,与稀释1500倍的75%三环唑(WP)和稀释500倍的40%稻瘟灵(EC)有显著性差异。活体喷雾接种试验表明,于湘晚籼12号秧苗长至3叶1心时,接种稻瘟病菌分生孢子悬浮液前24 h喷施稀释100倍的胞外抗菌物质稀释液,其叶瘟防效为75.32%;接种稻瘟病菌分生孢子悬浮液后24 h喷施稀释100倍的胞外抗菌物质稀释液,其防效为71.49%。【结论】JN005菌株胞外抗菌物质对稻瘟病菌的菌丝生长和孢子萌发有直接抑制作用,且对环境稳定性较好,对稻瘟病有较好的预防和治疗作用,有进一步的开发潜力。 相似文献
18.
不同基质配比下米老排组培苗移植效果 总被引：1，自引：0，他引：1
为探讨基质配比对组培苗移植效果的影响,以黄心土和泥炭土为基质,按照体积比设置5种基质配比处理,即T1（100%黄心土）、T2（80%黄心土+20%泥炭土）、T3（60%黄心土+40%泥炭土）、T4（40%黄心土+60%泥炭土）和T5（20%黄心土+80%泥炭土）,分析不同基质处理对米老排组培苗移植成活率、生长量和苗木质量指数的影响效应。结果表明：T1和T3处理有利于提高米老排组培苗移植后成活率,移植1个月的苗木成活率以T1最高（83.33%）,T3次之（81.11%）;随着泥炭土比例的增加,米老排组培苗的株高、叶片数、地径均呈先增加后降低的变化规律,并在T3时达到峰值,移植6个月的株高、叶数与地径分别为30.93 cm、8.1片和5.04 mm,均极显著高于其他4个处理（P<0.01）,分别是T1的2.11、1.82和1.67倍;6个月的苗木地上干重和地下干重大小均为：T3>T4>T5>T2>T1,T3的地上干重和地下干重分别为T1的8.51和5.56倍;T3的苗木质量指数达到了1.13,显著高于T5、T2和T1（P<0.05）。60%黄心土+40%泥炭的混合基质是米老排组培苗移植的理想育苗基质。 相似文献
19.
草地贪夜蛾是2019年1月新入侵我国云南的重大农业害虫,4月首次在海口玉米田中剥查发现该虫。草地贪夜蛾严重威胁到海南本地的鲜玉米生产,筛选出具有较高毒力水平的化学药剂防治该虫迫在眉睫。本文采用浸叶法测定了15种杀虫剂对草地贪夜蛾幼虫的毒力。实验结果表明,采用较低浓度的甲维盐（5 mg/L,24 h）和多杀菌素（5 mg/L,24 h）,以及较高浓度氯虫苯甲酰胺（50 mg/L,72 h）和辛硫磷（100 mg/L,72 h）时,对草地贪夜蛾幼虫的致死率达100%,这4种杀虫剂在24 h的LC50分别为0.28、0.31、9.77和11.7 mg/L;其他种类杀虫剂如灭多威、吡丙醚、氟虫腈、啶虫脒、阿维菌素、高效氯氰菊酯和虱螨脲,在100 mg/L浓度水平下,72 h对草地贪夜蛾幼虫的校正死亡率分别为100%、96.67%、88.33%、86.11%、81.67%、80.83%和80.09%。表明了可选用甲维盐、多杀菌素、氯虫苯甲酰胺和辛硫磷作为主要成分的杀虫剂,并组合其他种类杀虫剂,作为当前防治草地贪夜蛾幼虫主要防治药剂。 相似文献
20.
为探讨茶园间作对茶园小贯小绿叶蝉（Empoasca onukiiMatsuda）的生态调控作用,本研究开展樱花（Cerasus sp.）、圆叶决明（Chamaecrista rotundifolia）、油菜（Brassica napus L.）间作茶园中小贯小绿叶蝉种群时序动态,及其天敌功能团组成结构、种群数量时序变化调查,分析间作茶园中小贯小绿叶蝉天敌功能团群落多样性和益害比。结果显示：樱花-茶、圆叶决明-茶和油菜-茶中小贯小绿叶蝉的时间动态变化趋势与常规茶园无显著差异,但发生量较同期常规茶园显著下降（P=0.034<0.05）,全年分别下降25%~225%、20%~82.6%和20%~100%;经调查、鉴定得出,同期茶园小贯小绿叶蝉天敌功能团隶属于蜘蛛目、脉翅目和膜翅目,共计9个科、12个种,均为肉食性节肢动物;不同间作茶园中小贯小绿叶蝉天敌功能团种群的优势种、从属种和偶见种存在差异;与常规茶园相比,樱花-茶、圆叶决明-茶可显著提高蜘蛛、捕食性昆虫和寄生性昆虫的种群数量（P<0.05）,油菜-茶可显著提高茶园中捕食性昆虫和寄生性昆虫的发生量,但对蜘蛛的发生量无显著影响;樱花-茶的小贯小绿叶蝉与天敌功能团益害比显著高于油菜-茶和圆叶决明-茶;多样性指数分析显示,樱花-茶、圆叶决明-茶、油菜-茶的小贯小绿叶蝉天敌功能团群落多样性与常规茶园存在显著差异,且通过聚类分析得出,当兰氏距离为4.79时,茶树间作模式分为2类,一类为常规茶园,一类为樱花-茶、油菜-茶和圆叶决明-茶。研究结果表明,间作樱花、圆叶决明、油菜能有效降低茶园中小贯小绿叶蝉的发生量,提高天敌功能团的种群数量和益害比,对小贯小绿叶蝉的发生起到明显的生态控制作用。 相似文献