为了解甘肃省玉米制种区线虫的危害，2018年采集张掖市玉米田矮小、早衰的病株及根际土样，分离获得一个胞囊线虫群体。经形态学特征鉴定并结合分子生物学分析，确定该病原为旱稻胞囊线虫(Heterodera?elachista)。致病性测定结果表明，该线虫是引起玉米植株矮小、叶片发黄等症状的病原。测定不同温度和玉米根系分泌物、玉米根汁、土壤浸液等孵化液对线虫孵化率的影响，及不同温度下初孵幼虫和2龄幼虫的存活状况，结果表明，该胞囊线虫群体孵化适宜温度为28 ℃。28 ℃下，2龄幼虫存活时间为22 d；25 ℃下，存活时间为24 d；5 ℃下，存活时间为30 d以上，且2龄幼虫死亡率最低。玉米根分泌物、土壤浸液和20倍稀释玉米根汁对旱稻胞囊线虫的孵化促进作用明显，而5倍稀释玉米根汁和4 mmol/L氯化锌溶液对线虫孵化有抑制作用。
英文摘要:
The corn root systems and the rhizosphere soil samples were collected according to symptoms of dwarf and earlier withering plants to learn the damage of plant nematodes in the seed corn production areas of Zhangye city, Gansu Province in 2018, and a population of cyst nematode was isolated. The pathogen was confirmed as Heterodera elachista by identification of morphological characteristics and molecular biology analysis. The pathogenicity test results showed that the symptoms such as shortness of the corn plants and yellowing of the leaves were caused by this nematode population using artificial inoculation. The effects on the hatching of the nematode in different temperatures and hatching solutions corn root exudates, corn root juice, soil infusion were studied, and the survival of the newly hatched juveniles and the second-stage juveniles(J2) at different temperatures. The results showed that the suitable hatching temperature for the cyst nematode was 28 ℃. At 28 ℃, the survival time of J2 was 22 d; at 25 ℃, the survival time of J2 was 24 d; at 5 ℃, the survival time was more than 30 d, and the mortality of J2 was the lowest. Corn root exudates, soil infusion and 20 times corn root juice could obviously promote the hatching of the Heterodera?elachista, while 5 times corn root juice and 4 mmol/L zinc chloride solution inhibited hatching.
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