3种药剂拌种控制稻秆潜蝇的效果

用60%吡虫啉悬浮种衣剂、60%吡虫啉微囊悬浮剂、20%丁硫克百威乳油对水稻拌种控制稻秆潜蝇。试验结果表明,水稻移栽前10 d,60%吡虫啉悬浮种衣剂对稻秆潜蝇的防治效果在85%以上,水稻移栽前3 d,60%吡虫啉悬浮种衣剂对稻秆潜蝇的防治效果在80%以上。说明60%吡虫啉悬浮种衣剂能有效减轻稻秆潜蝇的为害。     

闽东山区稻秆潜蝇发生规律及防治

稻秆潜蝇(chlorops oryzaeMatsumura)又称稻秆蝇,稻钻心蝇,双尾虫,属双翅目,黄潜蝇科,是我县山区单季稻的主要害虫,近年来危害呈上升趋势,每年发生面积6660hm2,占水稻播种面积58.8%,每年造成粮食损失2000t以上。为了摸清闽东山区稻秆潜蝇发生规律,控制稻秆潜蝇的发生为害,确保水稻增产。笔者于2002~2006年对稻秆潜蝇的发生及防治技术进行了系统调查研究。1发生规律1.1年生活史稻秆潜蝇在南屏县1年发生3代,其中水稻上发生2代,以幼虫在田边禾本科杂草上越冬,越冬幼虫3月下旬至4月上旬化蛹,第1代成虫于4月下旬、5月初陆续迁入单季稻秧田产卵,4…     

遵义县稻秆蝇发生规律及防治技术研究

２０世纪８０年代以来 ,由于杂交水稻组合的大面积推广种植 ,我县水稻稻秆蝇由次要害虫上升为主要害虫 ,为害逐年加重。第１代幼虫对秧苗为害率一般为３０%～５０% ,高的可达９０%以上 ,第２代幼虫伤穗率一般为１５%左右 ,高的可达５０%以上 ,严重影响水稻产量。为了有效地控制其发生和为害 ,近年来我们对其发生规律和防治技术进行了全面系统的观察研究 ,现将结果报告如下 :１发生规律稻秆蝇（ＣｈｌｏｒｏｐｓｏｒｙｚａｅＭａｔｓｕｍｕｒａ） ,属双翅目 ,秆蝇科 ,别名稻秆潜蝇 ,是一种为害禾本科植物的钻蛀性害虫。１．１生活史稻秆蝇在…     

鄂西山区稻秆潜蝇发生规律与防治

稻秆潜蝇是鄂西武陵山区水稻上的主要害虫之一，在宣恩１ａ发生３代，以第３代幼虫在禾木科杂草心叶内越冬。第１代幼虫危害稻苗心叶，轻者植株生长弱小，重者心叶枯萎，生长点腐烂，不能成苗；第２代幼虫危害水稻孕穗，造成穗形扭曲，抽穗后，部分或大部颖花残缺不实，单穗损失２０％～６０％。湾槽田、阴湿田的杂交稻受害最重。在稻秆潜蝇卵孵始盛期至高峰期用４０％乐果乳油２００～２５０ｍｌ／６６７ｍ^２对水６０ｋｇ喷雾，或３％呋喃丹颗粒剂２～２．５ｋｇ／６６７ｍ^２拌细土５０ｋｇ撒施，防效达８０％以上     

二代稻秆潜蝇被害率与卵株率相关性的研究简报

70年代以来,随着杂交水稻的推广,稻秆潜蝇(Chlorops′oryzae mats.)已急剧上升为丘陵和高、中海拔山区一季水稻主要害虫。以一代幼虫蛀食水稻秧苗心叶,致使叶片沿叶脉呈丝状破碎,破坏生长点,抑制水稻秧苗的生长;以二代幼虫钻入心叶,取食幼穗,最后留下半截或大半截,形成空秕。对于稻秆潜蝇的发生规律和为害习性近几年各地植保界相继进行了研究,作者于1985—1988年对其一、二代为害损失和防治指标进行了探讨,现将二代稻秆潜蝇被害率与卵株率相关性的研究简报于后。     

稻秆潜蝇综合防治技术研究

稻秆潜蝇是浙南山区水稻生产的重要害虫.通过推广薄膜育秧、绿肥田除草、选用抗性品种、实行健身栽培、生态控制等一系列综合防治技术,可达到经济有效的防治效果.在水稻整个生长期可减少用药1～2次,稻秆潜蝇穗被害率减轻41.03%,病虫害损失控制在3.6%以内,稻谷增产9.2%,稻田害虫天敌蜘蛛和黑肩绿盲蝽分别增加38.1%和26.3%,获得了明显的生态、经济效益.     

豌豆潜蝇姬小蜂对4种寄主植物上美洲斑潜蝇幼虫的选择性及适合度

在室内研究了豌豆潜蝇姬小蜂对4种寄主植物上美洲斑潜蝇2龄末-3龄初幼虫的选择性和寄生蜂子代生长发育及存活情况。结果表明,豌豆潜蝇姬小蜂雌蜂对不同寄主植物具有选择性差异,对菜豆选择性最强,对番茄选择性最低,斑潜蝇被致死率和被寄生率分别为96.1%、71.4%和73.4%、52.1%;在4种寄主植物上,寄生蜂对寄主的寄生数与致死数比值无显著差异。寄生不同寄主植物上斑潜蝇幼虫的豌豆潜蝇姬小蜂从卵发育到成虫的历期存在差异,在黄瓜上历期最长,为10.21d;寄生蜂蛹期稍短于卵期与幼虫期之和;但寄生不同寄主植物上斑潜蝇幼虫的寄生蜂卵孵化率、幼虫存活率、羽化率无显著差异。     

桐梓县稻秆潜蝇发生与防治

稻秆潜蝇在桐梓县 1996年以前是零星发生的一种次要害虫。近年来 ,发生面积不断扩大 ,60 0～12 0 0ｍ海拔地区均有不同程度的发生 ,全县每年发生 2 667ｈｍ2 左右 ,一般为害损失 10 %左右 ,为害重的达 4 0 %以上 ,已上升为桐梓县中、高海拔稻区的主要害虫之一。为了切实掌握稻秆潜蝇在桐梓县的发生和为害规律 ,有效的开展稻秆潜蝇防治工作 ,桐梓县植保植检站进行了系统的监控和调查 ,基本掌握了该虫发生、发展为害的规律 ,现将监控、调查的结果总结如下 :1　生活习性稻秆潜蝇属双翅目、秆蝇科 ,又名稻秆蝇 ,是一种为害禾本科植物的钻蛀性害…     

基于全长转录组测序的稻秆潜蝇解毒代谢相关基因筛选

为筛选水稻害虫稻秆潜蝇Chlorops oryzae潜在的解毒代谢酶基因，利用PacBio Sequel Ⅱ测序平台对稻秆潜蝇幼虫进行全长转录组测序，基于测序结果筛选稻秆潜蝇的解毒代谢相关基因谷胱甘肽S-转移酶（glutathione S-transferase，GST）基因、羧酸酯酶（carboxylesterase，CarE）基因和细胞色素P450（cytochrome P450，CYP450）基因，并检测其在稻秆潜蝇不同发育阶段的相对表达量。结果表明，对稻秆潜蝇进行测序得到18 100条去冗余转录本序列，共有16 283条序列得到注释。通过比对分析共筛选出8条GST、12条CarE和28条CYP450基因序列，这些基因在稻秆潜蝇不同发育阶段的表达量具有显著差异，表明不同虫态的稻秆潜蝇其解毒代谢能力可能不同。此外，还筛选到1 452个lncRNA序列，以及176个潜在的lncRNA靶基因序列，其中4个与解毒代谢基因相关。表明筛选获得的稻秆潜蝇解毒代谢酶基因及lncRNA靶基因可用于后续该虫的潜在抗药性研究及防治药剂筛选。     

稻秆潜蝇发生消长因素

稻秆潜蝇(Chlorops oryzae Matsumura)亦名稻秆蝇,近年来在我县为害猖獗。水稻苗期受害,叶子纵裂破碎,严重时呈枯心苗;孕穗期受害,穗头残缺变白,粒数减少,严重时仅剩扭曲的穗轴,影响产量。 稻秆潜蝇大部分以幼虫在日本看麦娘(Alopecurus japonicus Steud)、华北剪股颖Agrostis clavata Trin等杂草上取食越冬。在我县年发生3—4代,以3代为主。     

Investigation of rice blast development in susceptible and resistant rice cultivars using a gfp‐expressing Magnaporthe oryzae isolate

In this study, an isolate of Magnaporthe oryzae expressing the green fluorescent protein gene (gfp) was used to monitor early events in the interaction of M. oryzae with resistant rice cultivars harbouring a blast resistance (R) gene. In the resistant cultivars Saber and TeQing (Pib gene), M. oryzae spores germinated normally on the leaf surface but produced morphologically abnormal germ tubes. Germling growth and development were markedly and adversely affected in leaves of these resistant cultivars. Penetration of host cells was never seen, supporting the idea that disruption of germling development on the leaf surface might be one of the resistance mechanisms associated with Pib function. Thus, this particular R gene appeared to function in the absence of host penetration by the fungal pathogen. Confocal laser scanning microscopy of M. oryzae‐infected susceptible rice cultivars showed the dimorphic growth pattern that is typically observed during the biotrophic and necrotrophic stages of leaf colonization in susceptible cultivars. The suitability of the gfp‐expressing M. oryzae isolate for further research on R‐gene function and identification of resistant genotypes in rice germplasm collections is discussed.     

Reaction of <Emphasis Type="Italic">Leersia</Emphasis> grasses to <Emphasis Type="Italic">Xanthomonas oryzae</Emphasis> pv. <Emphasis Type="Italic">oryzae</Emphasis> collected from Japan and Asian countries

The present study was conducted to determine if there is specificity in the host-pathogen relationship between the isolates of Xanthomonas oryzae pv. oryzae, the causal bacterium for rice blight and Leersia grasses, the alternative weed hosts of the disease. Plants of three species of Leersia, namely, L. sayanuka, L. oryzoides and L. japonica, were collected from various parts of Japan and were inoculated with the X. oryzae pv. oryzae isolates obtained from various locations in Japan and from 11 Asian countries. Four L. sayanuka plants were found susceptible to all Race II isolates and some Race I isolates, but were resistant to all Race III isolates. Race III is known to have a wider range pathogenicity to rice cultivar groups compared with Race I and II. Although the reactions of two L. oryzoides plants to Race I and II isolates were similar to that of L. sayanuka, the L. oryzoides plant collected from Niigata Prefecture showed a susceptible reaction to some Race III isolates. On the other hand, L. japonica plants gave reactions different those of L. sayanuka and L. oryzoides, with two plants of L. japonica found to be resistant to all test isolates collected from Japan. The Asian isolates exhibited a wide host range against the international differential rice cultivars, but almost all of them were avirulent to Leersia plants. These results indicate that the relationship between the pathogenicity of the causal bacterium and the resistance of host plants is very complex, and suggest that pathogenic diversity of X. oryzae pv. oryzae might be related to the resistance of Leersia spp.     

不同葡萄品种对越冬代绿盲蝽的抗性分析

为明确不同葡萄品种对越冬代绿盲蝽Apolygus lucorum的抗性水平,于2012—2014年连续3年系统研究了不同葡萄品种上绿盲蝽的为害情况以及越冬卵量,并分析了绿盲蝽越冬卵量与葡萄受害指数之间的关系。结果显示,每年越冬代绿盲蝽对不同葡萄品种的为害情况均存在显著差异;不同葡萄品种对越冬代绿盲蝽的抗性不同,其中香悦对绿盲蝽抗性最强,抗性指数为5.00,金田美指抗性最弱,抗性指数为1.00;每年绿盲蝽在不同葡萄品种上的越冬卵量均存在显著差异;相关性分析表明,不同葡萄品种受害指数与绿盲蝽越冬卵量之间无显著相关性。研究表明,不同葡萄品种对越冬代绿盲蝽的抗性水平存在显著差异。     

Bacterial blight of rice and its control in Nepal

Research on Xanthomonas oryzae pv. oryzae, the bacterial blight of rice pathogen, was initiated at the Institute of Agriculture and Animal Science (IAAS) with the main objective of assessing the population structure of X. o. pv. oryzae through the use of both conventional and molecular markers in combination with virulence typing. A high DNA polymorphism was detected in the pathogen populations using different DNA probes and rep-PCR primers. Most strains were avirulent to cultivars containing the bacterial blight resistance gene Xa-21, which suggested the strategy that targets gene deployment is feasible in Nepal.     

Molecular and Pathotype Analysis of the Rice Blast Fungus in North Vietnam

Rice blast caused by Pyricularia oryzae is a devastating disease worldwide. In Vietnam, rice blast is especially severe in the Red River Delta in the North. The genetic diversity of 114 P. oryzae isolates collected from rice in 2001 in the Red River Delta and nine additional Vietnamese P. oryzae isolates was analysed using Amplified Fragment Length Polymorphism (AFLP). DNA similarity and cluster analysis based on 160 polymorphic AFLP markers showed twelve different AFLP genetic groups among the 123 field isolates. Isolates collected from japonica hosts clustered separately from indica host isolates with at least 60% dissimilarity with little evidence for gene flow between the two populations. In the 2001 population originating from indica hosts, three genetic groups were predominant and represented 99% of the isolates sampled. One predominant clonal lineage represented 59% of the 2001 indica host population and was found in eleven provinces in the Red River Delta of North Vietnam. Significant genotype flow could be demonstrated between the indica population south of Red river and the indica population north of Red river. There was significant linkage disequilibrium between the AFLP loci within the indica population, indicating that this is not a random mating population. Pathogenicity tests of 25 isolates selected from the 12 AFLP groups on a set of 29 differential rice lines revealed two avirulent isolates and 23 pathotypes. Different combinations of known resistance genes were found to have potential for blast resistance breeding for North Vietnam. First two authors contributed equally     

Long‐term survival of blast pathogen in infected rice residues as major source of primary inoculum in high altitude upland ecology

Magnaporthe oryzae is the fungal plant pathogen that causes rice blast. The sources of primary inoculum and overwintering mode of the fungus remain largely unknown. The effect of rice residues on the onset of blast epidemics and the potential for survival of M. oryzae in the residues were studied in upland conditions in Madagascar. Blast disease was observed in a 3‐year field experiment in three treatments: with either infected or uninfected rice residues on the soil surface, or without rice residues. Leaf blast incidence was significantly higher in the treatment with infected rice residues than in the two other treatments at the early stages of the epidemic. In a second set of trials, the survival of M. oryzae on rice residues was monitored. Infected rice stems were placed by lots in three places: on the mulch of rice residues, under the mulch, and buried at a depth of 10 cm in the soil. Each month, samples were taken from the field and tested for sporulation. The survival of the blast fungus decreased rapidly on the stems buried in the soil but remained high for the other conditions. Sporulation of the fungus was observed on stems left on the mulch for up to 18 months. It is concluded that under field conditions, the presence of infected rice residues could initiate an epidemic of blast. The results of this study may help in designing effective management strategies for rice residues infected by M. oryzae.     

Transmission of rice blast from seeds to adult plants in a non‐systemic way

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is a serious threat to rice production worldwide. In temperate regions, where rice is not cultivated for several months each year, little is known about the initial onset of the disease in the field. The main overwintering and primary inoculum sources reported are infested residues and seeds, but the subsequent steps of the disease cycle are largely unknown, even though a systemic infection has been proposed but not demonstrated. The present work follows rice blast progression in infected seeds from germination to seedling stage, with direct and detailed microscopic observations under both aerobic conditions and water seeding. With the use of GFP‐marked M. oryzae strains, it was shown that spores are produced from contaminated seeds, infect emerging seedling tissues (coleoptile and primary root) and produce mycelium that colonizes the newly formed primary leaf and secondary roots. Using different rice cultivars exhibiting distinct levels of resistance/susceptibility to M. oryzae at the 2/4‐leaf stage, it was observed that resistance or susceptibility of a considered genotype is already established at the seedling stage. The results also showed that when plants are inoculated either at ripening stage (mature panicles), heading stage (flowering/immature panicles) or even before heading (flag leaf fully developed), they produce infested seeds. These seeds produce contaminated seedlings that mostly die and serve as an inoculum source for healthy neighbouring plants, which gradually develop disease symptoms on leaves. The possible rice blast disease cycle was reconstructed on irrigated rice in temperate regions.     

黄芪根瘤象甲发生规律及生物学特性

为进一步明确黄芪根瘤象甲Sitona simillimus的发生规律和生物学特性,于2016—2019年采用田间系统调查和室内饲养试验对黄芪根瘤象甲的越冬规律、田间数量动态变化、生活习性和各虫态的发育历期进行调查,测定土壤湿度和寄主植物对成虫存活及发育的影响。结果表明,黄芪根瘤象甲以成虫在靠近植物根际处的土层内越冬,越冬适宜的土壤质量含水量为5%~10%。在甘肃省定西市黄芪根瘤象甲1年发生1代,越冬成虫产卵高峰期为每年5月下旬至6月中旬,幼虫发生高峰期为每年6月中旬至8月初,化蛹高峰期为每年7月下旬至8月上旬,成虫羽化盛期为每年8月下旬至9月上旬。黄芪根瘤象甲成虫羽化当年虽可取食,但不产卵,翌年越冬结束后开始取食,取食后即可产卵。在黄芪、红芪、苜蓿和三叶草中,只有取食黄芪叶片的雌成虫才能正常产卵繁殖。黄芪根瘤象甲成虫产卵的昼夜节律明显,产卵主要集中在12：00—22：00,单雌产卵量为2 051.4粒,产卵期为42.6 d。卵、蛹和幼虫的平均发育历期分别为9.8、10.6和36.7 d。