Refinement of Passive Nematode Recovery from Cotton Growing High Clay Content Australian Vertisols

Vertisols are characterized by their high clay content, which can hinder assessment of their soil biology. Recovery of nematodes from vertisols with active techniques has indicated that free living nematode numbers within Australian vertisols are often low. Despite this, cotton yield losses due to the reniform nematode have recently been reported in Australia. In light of this and other changes in the cotton production system, we undertook a series of experiments to determine whether passive nematode extraction techniques could be applied to high clay vertisols. Existing published passive nematode recovery methods proved to be inefficient. The use of sodium hexametaphosphate as a clay dispersant was found to further reduce effectiveness. Instead, direct extraction of soil in Ludox at 1.1 g/cm³ followed by sieving was found to be as effective at recovering nematodes using Baermann funnel extraction from fresh soil but considerably quicker and three times more effective with dried soil.     

Efficacy of neem seed derivatives against nematodes affecting banana

Soil applications of powdered neem seed or neem cake at 100 g/plant at planting and, subsequently, at 3-month intervals, reduced the populations ofPratylenchus goodeyi Sher & Allen andMeloidogyne spp. on par with Furadan 5G (carbofuran) applied at 40 g/plant at planting and then at 6-month intervals to banana plants grown in 100-/ containers with controlled levels of banana nematode infestations. Eight months after planting, banana plants treated with powdered neem cake, seed or kernel or with neem oil had 4 to 95 times fewer parasitic nematodes than the untreated control. However, only neem cake powder or neem seed powder applied to unpared banana plants kept the nematode population below the economic threshold.     

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,线虫病害即其中之一.2003-2007年,笔者对云南省主要石榴产区蒙自县、会泽县和建水县的石榴寄生线虫进行了采样调查,采用形态特征进行鉴定,分离鉴定出了刻痕短体线虫.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.     

茶木蠹蛾生活习性及有效积温

茶木蠹蛾ＺｅｕｚｅｒａｃｏｆｆｅａｅＮｉｅｔｎｅｒ是茶树的主要枝干害虫之一,尤其是新辟茶园被害严重。在安徽省一年１代,以老熟幼虫越冬,幼虫期为５龄,危害期长达１２０—１５０ｄ,一生中可转移钻蛀５—１０个枝干。经变温测定：蛹期发育起点温度Ｃ＝（１５．０±０．７）℃,有效积温Ｋ＝（１７４±１２）ＤＤ,预测式Ｎ＝（１７４±１２）／〔Ｔ－（１５．０±０．７）〕（ｄ）,卵期发育起点温度Ｃ＝（１７．６±０．８）℃,有效积温Ｋ＝（１２４±７）ＤＤ,预测式Ｎ＝（１２４±７）／〔Ｔ－（１７．６±０．８）〕（ｄ）。     

杜仲林咖啡豹蠹蛾发生及防治建议

本研究对咖啡豹蠹蛾的生物学特性进行了观察,调查了对杜仲的危害情况,并对该虫的防治进行了初步探讨     

1种苎麻根腐病线虫的鉴定

【目的】对分离的一种苎麻根腐病线虫进行形态和分子生物学鉴定,为病原线虫分子生物学检测技术的研发及苎麻根腐病的防治奠定基础。【方法】从感染苎麻根腐病植株根中分离出一种植物病原线虫,利用显微技术观察线虫的形态特征,对其进行初步鉴定;之后采用分子生物学技术,提取单条线虫的DNA,利用通用保守性引物扩增了线虫核糖体DNA内部转录间隔区(rDNA-ITS)序列,并用软件DNAstar和DNAMAN进行序列分析,对该植物病原线虫进行进一步鉴定。【结果】根据形态特征,将获得的苎麻根腐病线虫初步鉴定为咖啡短体线虫。序列分析结果表明,该线虫rDNA-ITS序列与咖啡短体线虫湖北种群、越南种群、台湾种群、日本种群及尼日利亚种群的同源性依次为99.8%,99.0%,98.0%,97.8%和94.6%。该线虫rDNA-ITS序列在GenBank注册号为HQ403649。【结论】形态及分子生物学鉴定结果表明,分离的苎麻根腐病线虫为咖啡短体线虫(Pratylenchus coffeae)。     

The influence of the topographic position within highlands of Western Rwanda on the interactions between banana (Musa spp. AAA-EA), parasitic nematodes and soil factors

Soil properties vary according to the topography. They affect water uptake and root exploration in the soil. Consequently, they may also influence the spread of plant–parasitic nematodes. This study reports on the effect of toposequence-related variations in soil on banana yields, foliar nutrient status, and nematode impact. Twenty banana plots were visited within 6 hills/valleys at each of the three toposequence positions: valley bottom, mid-slope and crest. Important variability in plant growth, nutrition and soil properties was observed within the toposequence. Significantly better plant growth (height and girth) was observed in the valley bottoms, where banana bunch weight was 1.7–3.4 kg higher (although not significant) than at upper toposequence positions. Best plant growth was observed in valley bottoms in contrast to the highest N and K foliar deficiencies in this position. Plants in the valley bottoms had higher foliar Ca and Mg, and K compared to those in the crest. Plants in the mid-slope had greater percentage of dead roots (19.1%), compared to the plants in the valley bottoms (12.3%) and the crest (14.2%). Soils in the valley bottoms were deeper, sandier, with lower organic matter, lower N, and K compared to the soils at higher toposequence. Nematodes likely play a key role in banana root damage, however, their effect appear to be in relation to various soil factors at each position. The abundance of Pratylenchus goodeyi had generally limited impact on banana yields in fields having less than 5% slope (crest and valley bottom) where soil conditions were more optimal for root growth. However, in the presence of increased run-off on steeper middle slopes, root death was increased even under moderate pressure from P. goodeyi.     

斯克里布纳短体线虫在华北的寄主范围和克线磷防治作用的研究

盆栽试验证明，我国北方大豆、马铃薯、高粱、小米、棉花、小麦和番茄都是斯克里布纳短体线虫（Ｐｒａｔｙｌｅｎｃｈｕｓｓｃｒｉｂｎｅｒｉ）的寄主．并首次发现Ｐ．ｓｃｒｉｂｎｅｒｉ也能侵害油菜．罹病植株根部出现不同程度的坏死症状，根系生长不良．植株长势衰弱．Ｐ．ｓｃｒｉｂｎｅｒｉ在花生和心叶烟上繁殖极少，也不诱发明显根斑．用克线磷（５Ｇ）５ｋｇ／ｈｈ２和１０ｋｇ／ｈｈ２用药量均为有效成分）在玉米播种时处理土壤，防治效果分别高达９９．６％和１００％．     

石榴豹纹木蠹蛾(Zeuzera coffeae Nietner)生物学及其防治研究

石榴豹纹木蠹蛾是云南蒙自地区石榴的主要害虫之一。幼虫蛀害石榴树枝干 ,具多次转移危害习性 ,并在蛀道内越冬。受害部位以上枝干萎蔫、枯死 ,危害枝干率达 1 0 %～ 1 5 % ,重者达 30 %～ 40 %。该虫在云南蒙自石榴植区一年发生一代 ,垮年度完成 ,越冬态不甚明显。采取综合防治措施后 ,其危害率由 1 0 %～ 1 5 %降为 0 .2 %～ 0 .31 %。