玉米丝黑穗病菌冬孢子萌发湿度及云南玉米新品种抗性鉴定研究

Effect of Soil Humidity on Germination of Sphacelotheca reiliana teliospore and Head Smut Resistance Identification for New Maize Varieties in Yunnan Province

玉米丝黑穗病直接损坏果穗,造成玉米产量的严重损失。为了获得抗病品种,试验在得到最佳接种条件后,开展了人工接种鉴定玉米抗性。结果表明:在22℃和有萌发的玉米种子及土壤湿度为20%～25%条件下,有利于玉米丝黑穗病菌冬孢子萌发,但在无玉米种子时,则不能萌发。采用1%冬孢子制作的带菌土接种方法于2007年和2008年在昆明市和施甸县两个病圃鉴定了云南省302份玉米新品种对丝黑穗病的抗性,其中,高抗、抗病、中抗、感和高感品种分别为65份,118份,27份,86份和6份,各占供试材料的21.45%,38.94%,8.91%,28.38%和1.98%。依据株发病率就是损失率的特点,建议在重病区,只宜推广抗病和高抗品种。

Head smut reduces maize yield severely because of its damage on ears right. In order to gain the resistant varieties , the study on inoculation condition and resistance identification by artificial inoculation showed： teliospores of Spmhacelotheca reiliana could germinate very well at 22 ℃ and between 20%-25% soil humidity with germinating maize seed, however, they could not without the seed. In 2007 and 2008, 302 new maize varieties from Yunnan Province were identified for their head smut resistance by the inoculation with soil carrying 1% teliospore in two disease nurseries in Kunming City and Shidian County. Among them, 65, 118, 27, 86 and 6 varieties were highly resistant, resistant, moderately resistant, susceptible and highly susceptible to the disease with 21.45%, 38.94%, 8.91%, 28.38% and 1.98%, respectively. It was suggested that only resistant and highly resistant varieties should be extended in severe disease areas based on the coincidence of incidence with loss rate.