龙眼顶芽瘿螨发生为害与药剂防治初步研究

龙眼顶芽瘿螨（ＥｒｉｏｐｈｙｅｓｄｉｍｏｃａｒｐｉＫｕａｎｇ）是龙眼树的一种新害螨,该螨在广西南宁市全年均可发生,但１－３月,７－８月为害稍轻,５－６月,１０－１１月发生为害较普遍,种群数量较大,龙眼鬼帚病株的病梢上,顶芽有螨芽率平远达７５．２８％－８０．５６％,健株上的顶芽有螨芽率为４１．８１％－４４．５８％;龙眼健株上的未萌动顶芽有螨芽率平均为６７．５％－８７．９２％,而已萌动的顶芽有螨芽率为     

荔枝鬼帚病及其与龙眼鬼帚病相关性的初步研究

 荔技鬼帚病(LiWBV)可侵染不同品种和不同龄期的荔枝,引起幼叶卷缩似月牙形、侧枝丛生呈扫帚状、花穗密集成簇生等症状。在电镜下首次在病叶内找到线状病毒粒体。该病症状和病原形态与龙眼鬼帚病(LWBV)相似,媒介昆虫同是荔枝蝽,通过该昆虫介体,LiWBV和LWBV均可传到两种寄主植物上。由此推断,两种病害可能是由同种病毒侵染所致。     

龙眼鬼帚病的昆虫传病试验

 1985~1989年进行了荔枝蝽,龙眼角颊木虱和龙眼鸡传染龙眼鬼帚病以及荔枝蝽从龙眼到荔枝的传病试验。结果指出:荔枝蝽成虫、幼虫和龙眼角颊木虱成虫均能传染龙眼鬼帚病,传病率分别为18.8-36.7% 40.0-45.0%与23.3-37.9%。试验苗的潜育期,短的为2-3个月,长的约一年。龙眼鸡和对照处理的试验苗均无发病。电镜检查结果表明:在荔枝蝽(成虫)唾液腺细胞内所见的线状病毒粒体,与龙眼鬼帚病叶组织采用超薄切片所观察到的病毒粒体,在形态结构上基本相同,进一步确认介体昆虫传病的可靠性。荔枝蝽成虫,若虫还能将龙眼鬼帚病传到荔枝上,引起与龙眼鬼帚病十分相似的病状。这一结果为揭示荔枝鬼帚病和龙眼鬼帚病之间的密切关系提供了新证据。     

龙眼病虫害的综合防治

龙眼病虫害的种类很多 ,但主要病害有龙眼扫帚病 ,也叫鬼帚病。虫害主要有荔枝蝽、龙眼角颊木虱、荔枝蒂蛀虫等 3种。也就是常说的 3虫 1病。 3虫 1病危害期大都集中于新梢期、花期、幼果期及果实近熟期 ,造成枯枝、落花落果、虫粪果。因此 ,防治策略上应以 3虫 1病为主要对象 ,采取有效的保梢、保花、保果等措施。重点应抓好以下几项综合措施 :1　新建果园要选择优良的嫁接苗种植要求苗木嫁接口愈合良好 ,没有畸形、肿大、叶片黄化等不良现象。苗木生长要健壮、叶片整齐、叶色浓绿 ,并且特别要求没有鬼帚病及蚧壳虫等。2　做好防治病虫害保…     

龙眼鬼帚病的发生与防治

龙眼鬼帚病又叫丛枝病、扫帚病，在广西及广东、福建、台湾等省（自治区）均有发生。近年来，该病有逐步加重的趋势。此病为害嫩叶、枝梢和花穗，造成枝梢枯死，秃枝，嫩叶不能伸展，不久枯萎脱落，发病的花穗不能结果，严重影响树势生长和产量，是当前发展龙眼生产中极需...     

荔枝鬼帚病的初步调查及传病试验

 荔枝鬼帚病是福建荔枝上新近发现的病害,它与由病毒引起的龙眼鬼帚病状相似。近几年曾对本病进行了初步调查和传病试验,结果简报如下.     

辣椒茶黄螨的防治

辣椒茶黄螨的防治赵益友，刘雁南（湖南绥宁县农业局植保站，４２２６００）南方是辣椒的主产区。辣椒茶黄螨是主要的害虫之一，它的危害常被农户误以为是病毒病，不能对症下药，导致茶黄螨危害逐年加重。一般产量损失在５０％左右，严重的损失８０％以上。１为害症状新梢...     

荔枝瘿螨研究初报

荔枝瘿螨(Eriophyes litchi Keifer)。在荔枝、龙眼造成的为害,过去称为毛毡病,近年在桂南各地有逐步发展趋势。此螨已成为荔枝龙眼上的重要害螨。荔枝被害梢率最大达到54％,龙眼被害梢率最大达到69.6％,已严重地影响结果及树势生长。荔枝瘿螨无明显越冬现象,一年四季均可繁殖为害,被害叶率春梢为32.6％,夏梢为27.2％,秋梢为17.4％,冬梢为7.4％。被害嫩叶开始时长出稀疏的绒毛,初期毛毡呈灰白色,经17～34天后变为黄褐色,再经一星期左右转为红褐色,以后转为黑褐色。嫩果被害也出现毛毡,严重时导致落     

龙眼荔枝几种害虫的研究进展

近十年来，广西龙眼荔枝种植面积迅速扩大，目前已有400多万hm^2，随着龙眼、荔枝生产的发展，果园生态环境发生了变化，新出现一些害虫，如龙眼长跗萤叶甲（红头长跗萤叶甲）Monolepta occiflavis Gressitt et Kimoto、粉筒胸叶甲Lypesthes ater (Motshulsky)、龙眼亥麦蛾Hypitama Longanae Yang et Chen、三角新小卷蛾（黄三角黑卷蛾）Olethreutes Leucaspis Meyrick、龙眼瘿螨Erophyes dimocarpi Kuang等，来势猛，扩散为害大，对广西龙眼，荔枝生产影响较大，为了有效地控制这些害虫，现将研究进展综述如下。     

世高防治龙眼炭疽病试验

１０％世高WG（水分散粒剂）防治龙眼炭疽病具有高效、安全、耐雨水冲刷的特点。生产上适宜使用浓度为８００倍，在龙眼始梢期施药。笔者试验，施药后１４d对龙眼炭疽病的防效仍在８６．８％。如遇阴雨天气时，隔７d左右酌情补施药１次。世高防治龙眼炭疽病试验@陈润珍$广东省高明市植保站!广东高明528500 @区伟明$广东省高明市植保站!广东高明528500 @区肇康$广东省高明市植保站!广东高明528500     

枣疯病媒介昆虫-中华拟菱纹叶蝉生物学和防治的研究

本文报道了中华拟菱纹叶蝉形态特征、生物学特性、传病规律、天敌及防治试验等研究结果。寄主植物除枣树及酸枣树外,尚有榆树。枣疯树上远比健树上为多。一年发生四代,但第四代只局部发生。以卵越冬。冬卵孵化及产生的若、成虫整齐而集中。在成虫接种试验中,只第一代饲病7天者传病。已初步发现六种捕食性天敌。试验证实,甲基1605、乙基稻丰散、杀螟松及敌敌畏等对卵及成虫有明显的杀灭效果。     

枣疯病传病途径的研究

 枣疯病是我国枣树上一种严重的传染性病害。多年试验表明:土壤、花粉、种子均不传病,病叶汁液接种以及病健树根系在地下的自然接触也不传病;人工嫁接虽可传病,但枣树繁殖一般不通过嫁接,因而不是自然传病的途径。经过对在枣树上活动害虫的系统调查,1980年于河北玉田选常见的11种叶蝉进行了传病实验,证明橙带拟菱纹叶蝉(Hishimonides aurifacialis Kuoh)、凹缘菱纹叶蝉(Hishimonus sellatus Ulhler)和红闪小叶蝉(Typhlocyba sp.)均能传播枣疯病。从接种发病的实生枣苗维管束和媒介叶蝉的唾液腺的超薄切片中,都检查到枣疯病原类菌原体。鉴于这三种叶蝉普遍存在于北方枣区。因此,认为是枣疯病在北方枣区自然传病的主要媒介。     

草莓丛枝病的发现及初步研究

 在沈阳,从表现丛枝症的草莓、春香和宝交早生品种上,分离到新发生的类菌原体(MLO)。用小叶嫁接法测定指示植物草莓EMC和UC-10均能表现出典型的丛枝症(witchetbroom),病叶变小,颜色变浅。将病叶经固定和包埋后,制成超薄切片,于电镜下观察,可见到在韧皮部组织内有大量球形、椭圆形及哑铃形,并具有单位膜结构的类菌原体。用四环素处理病株可减轻症状。     

枣疯病传病昆虫研究(Ⅰ)传病昆虫——中国拟菱纹叶蝉

 作者等在1978年以9种不同昆虫接种传枣疯病的实验中(连对照共枣苗75株),于1979年6月发现直接采自疯树的中国拟菱纹叶蝉(Hishimonides chinensis Anufriev)在健康根蘖枣苗上传染了典型疯苗一株。1979年又继续扩大重复了9种不同昆虫的传病实验(连对照共枣苗300株),到1980年6、7月间,在五组中国拟菱纹叶蝉的重复处理中,有三组共六株枣苗出现典型疯株。两年来平均传病率为21.8%。潜育期10~12个月。将发病枣苗及传病的中国拟菱纹叶蝉唾腺超薄切片分别用电子显微镜观察,均明显存在多量典型的类菌原体(MLO),对照则没有。因此,初步证实中国拟菱纹叶蝉能传枣疯病。     

枣疯病的研究

 对枣疯丛枝与花、叶畸变的症状作了比较系统的观察和描述。病树根部的超薄切片和疯枝韧皮匀浆的部分提纯物在电镜下都检查到类菌原体(MLO)。健树的相应对照样品中未见任何病原物。试验表明:四环素族抗菌素对枣疯病有一定的疗效,少数病树经治疗后,外观康复,正常开花结果已维持两年之久。认为枣疯病是由MLO感染所致。     

Some experiments and considerations on the identification of witches' broom viruses,especially in clovers,in the Netherlands and Italy

Witches' broom phenomena (witches' broom growth + antholysis) observed inTropaeolum majus and in clovers in the Netherlands and in several wild and cultivated plants in Italy were demonstrated to be due to virus infection. The virus(es) could be transmitted by grafting, through dodder and by means of leaf-hoppers (Euscelis spp. primarily). The virus isolates found in both countries did not differ appreciably in the symptoms they caused. Many of the deviations concerned have been known for a long time as teratological phenomena. In the extensive literature considerable confusion exists concerning the identity of several witches' broom virus diseases. They constitute a good example of the problem of virus variability. A continuous splitting of witches' broom viruses on the basis of slight differences in symptom expression or of vector specificity does not seem justified. Since no intrinsic properties of the virus(es) concerned are known, the only conclusion that can be drawn from the information available is that the Dutch and the Italian isolates show a great similarity to aster yellows virus as well as to tomato big bud, stolbur and other witches' broom viruses.     

广东枣疯病植原体的鉴定

Several jujube plants with witches′ broom, little leaf, and big bud symptoms, which were likely infected by jujube witches′ broom (JWB) phytoplasma, were collected in Guangzhou, Guangdong Province. To identify the pathogen, PCR was performed using phytoplasma 16S rDNA universal primer pairs R16mF2/R1 and P1/P7 and SecA gene primer pair SecAfor1/rev3 with total DNA of the symptomatic plants as templates. Specific fragments, 1.4 kb, 1.8 kb, and 0.8 kb in length, were amplified from one of three symptomatic samples. Phylogenetic analysis based on 16S rDNA verified that the pathogen harming jujube plants in Guangzhou was jujube witches′ broom phytoplasma which belonged to 16SrV-B subgroup. Comparison results also showed that the 16S rDNA sequence of Guangzhou JWB phytoplasma shared the highest nucleotide identity (100%) with the reported jujube witches′ broom phytoplasma Japanese strain (AB442218) and JWB strain (AY197661) and shared the nucleotide identity ranging from 99.74% to 99.80% with the other JWB phytoplasma strains. In addition, phylogenetic analysis based on SecA also showed that Guangzhou jujube witches′ broom phytoplasma belonged to 16SrV-B subgroup and shared 99.28%-99.76% similarity with other phytoplasma strains. All these results suggested that jujube witches′ broom phytoplasma has infected jujube plants in Guangdong Province.     

海南岛几种绿肥作物丛枝病病原体的电子显微镜研究

 在广东省海南岛发现几种绿肥植物:巴西苜蓿、卵叶山蚂蝗、暗紫莱豆、爪哇大豆罹患了植物黄化病害。病株表现症状:植株矮化、枝叶丛生、叶变小、普遍退绿或黄化。电子显微镜观察发现,在病株叶柄韧皮部筛管细胞超薄切片中,存在大量的类菌原体(MLO)。这些菌体形态多样,有些可见菌体内纤维状样核酸物质,有的菌体正处于二分裂、或发芽状态。这些MLO大小分别为170~800nm、170~700nm、250~650nm、375~770nm。由于在病株中发现有MLO存在,而健株中则没有。可以初步认为四种绿肥植物丛枝病是由MLO所致。     

Witches' broom disease of cocoa in Rondonia, Brazil: infection of vegetative flushes and flower cushions in relation to host phenology

Formation of vegetative brooms and cushion infections were assessed in relation to host phenology and fructification of Crinipellis perniciosa over 2 years. Vegetative growth occurred in distinct periods or'flushes'based on an endogenous cycle of 8 weeks. Correlation analysis showed that growth patterns of the sample trees were very similar. There were four main flushes in 1984, three in 1985, and the first two in each year coincided with periods of fruiting of the fungus. Total yearly infection increased from 13% in 1984 to 32% in 1985 when there were more periods considered suitable for infection and production of basidiocarps. Many infections on young vegetative tissue produced more than one hypertrophied shoot (broom) and 11 new infections were produced from every fruiting broom in 1984 compared with 3.2 in 1985. The total number of vegetative brooms increased from about 160 per tree in September 1983 to about 650 in September 1985, despite natural broom loss of 68% every 12 months. Infection of flower buds (cushions) was related to flowering intensity and periodicity, and a small proportion of infected cushions produced brooms. The implications of these results are discussed in relation to methods of control.     

A novel phytoplasma associated with witches’ broom disease of Ligustrum ovalifolium in Turkey

California privet (Ligustrum ovalifolium Hassk.) plants exhibiting leaf yellowing, witches’ broom, dieback and decline symptoms were observed for two years (2010–2011) in three gardens at Adana region (Turkey). DNA isolated from symptomatic and healthy plants was used to amplify 16S rDNA fragments by direct and nested-PCR. Phytoplasmas were detected in 21 symptomatic plants, out of 30 samples collected, whilst no PCR amplifications were obtained from asymptomatic plants. BLAST analysis of the 16S rDNA showed that the phytoplasma found in L. ovalifolium from Turkey, denoted as Turkish Ligustrum witches’ broom phytoplasma (TuLiWB), most closely resembled members of group 16SrII (peanut witches’ broom group) and shared up to 92 % sequence identity. Based on in silico 16S rDNA RFLP analysis and automated calculation of the pattern similarity coefficient, TuLiWB showed molecular characteristics different from all previously described phytoplasma species to represent a new taxon. Similar indication also emerged from the phylogenetic tree which allocated it in a novel discrete subclade within the phytoplasma clade. This is the first report on the presence of a phytoplasma affecting L. ovalifolium and whether this novel phytoplasma is the same agent reported as a mycoplasma-like organism (MLO) and associated with witches’ broom disease of Ligustrum in Korea (1989) is yet to be determined.