黄瓜南方根结线虫病的根结大小与线虫各虫态数量间的关系

Relationship between Size of Root Knot and Quantity of Different Instars of Meloidogyne incognita in Cucumber

以黄瓜品种千秋1号为试材,采用室内试验方法,按南方根结线虫(Meloidogyne incognita)侵染千秋1号引起根系根结的大小统计线虫虫态及数量,并找出三者之间的关系。结果显示:日光温室栽培120d的黄瓜根系中,直径2～3mm的根结内有2～3条雌成虫,几乎100%根结表面附着1个卵块;直径4mm以上的根结内有1～5条2龄幼虫,根结表面附着2～8个卵块;长径16～20mm的根结内,成虫平均数量高达每根结42条。培养箱内接种线虫(每穴120条)45d的黄瓜根系中,直径5mm以上的卵块平均孵化出2龄幼虫807条,卵块在第3天和第7天孵化出的线虫数量最多。田间可根据根结大小和虫态的关系预测根结线虫的发生量和时期,建议在根结直径小于5mm时进行防治;试验所需线虫可在接种45d时取卵块,分别在第3天和第7天收集2龄幼虫。

Taking cucumber(Cucumis sativus L.)'Qianqiu No.1'as material and by room experimental method,according the size of root knots caused by root knot nematode(Meloidogyne incognita),this study caculated the stage and nematode numbers,and found out the relationship between them.The results showed that in solar greenhouse,there were 2-3 adults within the root knots of 2-3 mm diameter size in cucumber root system and almost each knot in this size had one egg mass.Within each larger size(over 4 mm in diameter)root knot,there were 1-5 2nd instar individuals and 2-8 egg masses.Within the knots of 16-20 mm long diameter size,42 individuals knot of adults on average could be found.After the 2nd instar root knot nematodes were inoculated into'Qianqiu No.1'cucumber for 45 days(inoculation rate:120 per plant),there were larger size eggs(over 5 mm in diameter),which could averagely hatch 807 individuals of 2nd instar.Larger amount individuals appeared on the 3rd and 7th hatching days.In cucumber growing fields,the quantity and occurring period of root-knot nematode can be predicted according to diameter sizes and stages,and the root knot nematode controlling time should be no later than the root knot in 5 mm diameter.In laboratories,the higher amount of the 2nd instar nematode could be obtained on the 3rd and 7th hatching days 45 days after inoculation in cucumber growing soil.