云南省柑桔根际短体线虫种类的鉴定

从采自云南省12个县市140个柑桔园的260份柑桔病根样本中分离鉴定出4种短体线虫属线虫:咖啡短体线虫(Pratylenchus coffeae),卢斯短体线虫(Pratylenchus loosi),穿刺短体线虫(Pratylenchus pene-trans)和伤残短体线虫(Pratylenchus vulnus)。其中咖啡短体线和伤残短体虫为优势种。     

高羊茅根际一种短体线虫的分离与鉴定

高羊茅(Festuca elata)是草坪草中绿期最长的一个草种,在草坪建植中具有重要作用。一些病害随着高羊茅种植范围的不断扩大而逐渐频发,对草坪造成极大经济损失。本研究通过调查北京市高丽营镇高羊茅斑块状枯死的原因发现,导致高羊茅枯死的是高羊茅根际优势植物寄生线虫。采用贝尔曼漏斗法分离了侵染北京地区高羊茅上的线虫,结合唇环、受精囊、食道、V值等形态学鉴定方法,证明高羊茅草根际优势植物的寄生线虫均为一种短体线虫,确定为斯克里步纳短体线虫(Pratylenchus scribneri)。线虫ITS和28S序列的PCR扩增及Gen Bank序列比对后发现,其与国外发现的P.agilis及P.scribneri序列相似度为93%,亦确证该线虫为斯克里步纳短体线虫。     

寄生台湾春兰的短体线虫种类鉴定

厦门国际邮轮港口岸检疫部门在检验1批来自台湾的春兰（Cymbidium goeringii）花苗时,发现部分花苗根部腐烂。经分离检验和组织染色,从中发现1个形态特征一致的寄生线虫种群。该线虫经进一步形态学观察和测量,鉴定为最短尾短体线虫（Pratylenchus brachyurus）。此种线虫寄主范围广、危害大,是我国对外公布的检疫性有害生物。春兰是最短尾短体线虫新纪录寄主。     

Post-anhydrobiotic viability ofpratylenchus thornei andmerlinius brevidens

After natural desiccation in the field, anhydrobiotic populations ofPratylenchus thornei Sher & Allen andMerlinius brevidens (Allen) Sidiqqi were treated in three different ways: some were kept dry to maintain nematodes in the anhydrobiotic stage; some were rehydrated and then allowed to dry again to induce a new desiccation cycle; and some were rehydrated and maintained as such, to reactivate and keep nematodes active.P. thornei populations from the dry treatment had a greater survival rate than the two other treatments. Culturing of the nematodes under wheat revealed that the three treatments did not alter the ability ofP. thornei to penetrate the roots, but nematodes given two cycles of desiccation had a greater rate of reproduction than those exposed to one desiccation cycle and kept in dry soil for a longer period (dry treatment). Survival ofM. brevidens rehydrated and retained in the active state was lower than that of nematodes undergoing the two other treatments.     

大蒜线虫蔬菜寄主调查

通过对５种大蒜线虫即洋葱茎线虫、甘薯茎线虫、马铃铃薯线虫、根腐线虫、肾形线虫在多种蔬菜上的接种试验，弄清了其蔬菜寄主范围。从而得出结论：在大蒜栽培中通过大蒜与其它蔬菜之间轮作或不同蔬菜轮作防治大蒜线虫是不可行的，只能药剂和生物防治。     

我国小麦落选短体线虫群体遗传多样性分析

为了明确我国落选短体线虫群体的遗传多样性,利用mtCOI基因标记对落选短体线虫9个地理群体的遗传结构及遗传分化进行分析。结果显示,9个地理群体中共得到101条mtCOI序列,发现28个碱基变异位点,形成14个单倍型。其中,H1单倍型最常见,为7个地理群体的59个个体共有,推测其可能为祖先单倍型。全部地理群体在物种水平呈现中等遗传多样性(H_T=0.706±0.131),聚类分析显示其可分为类群Ⅰ与类群Ⅱ两个类群,AMOVA分析揭示落选短体线虫整体水平的遗传分化主要来源于种群间。Mantel检验表明落选短体线虫群体的遗传距离与地理距离存在正相关性,但是不同种群之间的遗传分化程度与地理距离没有显著关系。中性检验和错配分布检验均揭示落选短体线虫在整体水平和两个类群上的群体历史动态都处于相对稳定的状态。     

Powdered neem seed and cake for management of the banana weevil,cosmopolites sordidus, and parasitic nematodes

Field trials were conducted in Kenya with ‘Nakyetengu’, an East African highland banana cultivar (AAA-EA), highly susceptible to banana pests. Regardless of soil fertility levels, incorporation around the plant base of powdered neem(Azadirachta indica A. Juss.) seed or cake at 60-100 g/mat at 4-month intervals, gave better control of the banana weevil,Cosmopolites sordidus (Germar), and of parasitic nematodes, than that achieved with soil application of Furadan 5G (carbofuran) at 60 g/mat at 6-month intervals. Compared with untreated control, fruit yield in most of the neem treatments was significantly higher, particularly during the second cycle of crop production. Neem application conferred a net economic gain, whereas Furadan application proved uneconomical. Application of powdered neem seed or cake at higher rates (200–400 g/mat) at 6-month intervals caused phytotoxicity, resulting in drying up of banana plants before fruiting, or in ‘chokethroat’,i.e., inflorescence emergence failure.     

Nematodes and weevil of bananas and plantains in Cameroon: Occurrence,importance and host susceptibility

The resistance of ashgourd to the melon-cottonaphid, Aphis gossypii (Glover), and the incidence of aphid-transmitted viral diseases was investigated following recording of aphid numbers and trichome (plant hair) numbers per cm² of leaf on four parts of the cucurbit, ashgourd, representing four genotypes (Local Sylhet, Local Round, High Female and CQ-10-90). The Local Sylhet genotype was found to have the highest trichome density compared with those of Local Round, High Female, and CQ-10-90 ashgourd genotypes, and was least infested by Aphis gossypii. The percentage of virus-infected plants was also found to be lowest on the Local Sylhet genotype. Aphid numbers were lowest on the terminal and young leaves of ashgourd compared with mature and senescent leaves, due to the higher trichome density in the former leaf categories. Trichome density was found to have a significant negative influence on the number of aphids. Trichomes in ashgourd play a major role by providing a first line defence in reducing aphid infestation, with a subsequent beneficial effect of reducing the incidence of virus.     

云南石榴根际刻痕短体线虫的鉴定

近年来云南石榴病害日趋严重,特别是根部病害,因为其危害具有隐蔽性,常被人们忽略,线虫病害即其中之一。本文首次报道了寄生于云南省石榴根际的一种短体线虫: 刻痕短体线虫Pratylenchus crenatus, Loof 1960,石榴是这种线虫的新记录寄主。