茶苗南方根结线虫的生物学研究

STUDIES ON THE BIOLOGY OF MELOIDOG YNE INCOGNITA (NEMATODA) INFESTING YOUNG TEA TREE

世界上约有25个国家种植茶(Camellia sinensis),其中10个国家被认为是主要的产茶国,我国也是其中之一。根结线虫严重侵染茶苗,可导致育苗工作大规模失败,有时整个茶圃都给毁了。与茶苗有关的根结线虫已报告4种(P.Sivapalan in J.M.Webster,1972)。作者曾指出福建同部南方根结线虫(Meloidogyne incognita)是茶苗寄生线虫的优势种,并进行了季节动态观察(潘沧桑等,1990)。本文继续报告其虫卵的发育和寄生阶段的发育的研究。1883年 Muller 首次描述一种根结线虫的生活史并画了图,但由于在

The present communication reports on our studies of the embryonic and postembryonic development ofMeloidogyne incognita infesting young tea tree.On the 1st day the single embryonic cell of egg divided into 4 cells.On the 2nd day 6-8 embryonic cells ap- peared.On the 3rd day 12-16 embryonic cells appeared.On the 4th day 32-64 embryonic cells appeared.On the 5th day more embryonic cells(blastula)appeared.On the 6th day the worm-like embryo appeared(like a tadpole).On the 7th day the larva appeared in an embry- onic form('S'-like).On the 10th day styler and esophageal metacorpus had formed.Then the embryonic form.casted off its skin and became the second stage larva.On the 13th day the larva hatched.The authers observed and compared the whole process of the embryonic devel- opment of three eggs of M.incognita from that of Camellia sinensis(L.)O.Ktze and two eggs of the same root-knot nematode from that of Sedum kamtschaticum Fisch and concluded that the developmental stages they involved were identical and the time they needed were equal. The young tea plants grown in sterilized soil were inoculated with the larvae hatched from the egg masses of M.incognita,2000-3000 larva per seedling,and kept at room temper- aturc 30℃ in the summer.Their galls were dissected at 10th,15th,20th,30th and 38th day af- ter inoculation.The obtained nematode bodies were dissected after measurement had been taken and their structures of the internal parts were observed.After infection the length and width of the female bodies,the length and width of their gonads,the volume of their egg masses,the width of their vulvae and the distance from vulva to annus increased gradually. On the other hand,the length of the stylet,the volume of esophageal metacorpus and the dis- tance from the dorsal esophageal gland duct orifice to the base of spear knobs had hardly any change.Under the condition of the temperature of 30℃,the peak of oviposition of females was about of the 30th day after inoculation,and the continuous three molts took place in about 10th day after inoculation.