云南江城雪茄烟根结线虫病的病原鉴定及生物源氨气熏蒸的防治效果研究

雪茄产业是近年来中国烟草行业新的经济增长点，雪茄烟种植中根结线虫病危害严重.然而，目前国内外雪茄烟病原线虫的种类尚未明确，对该病害的绿色防控也鲜有报道.基于雌虫、雄虫和二龄幼虫的形态特征、PCR扩增特异性条带及科赫法则验证结果，将普洱市江城县雪茄烟叶“云雪1号”品种上发生的根结线虫病病原鉴定为爪哇根结线虫（Meloidogyne javanica）.评估了4种食用菌（金针菇、杏鲍菇、香菇、姬菇）菌渣脲酶催化尿素释放氨气熏蒸土壤对雪茄烟叶爪哇根结线虫病的防治效果.结果表明：致死100%二龄幼虫（J2）所需的NH3最低质量浓度为136.8 mg/m3；将含4%尿素的4种菌渣分别与土壤按质量比为1∶18的比例混合，在水分含量约60%、28℃下放置3 d时，各处理组释放的氨气质量浓度在130.9～218.7 mg/m3，对根结线虫病的防效在75.7%～92.3%.研究结果显示“菌渣+尿素”熏蒸土壤对防控雪茄烟根结线虫病具有很好的应用潜力.

Pathogen identification of root knot nematode on cigar tobacco in Jiangcheng of Yunnan and the control effects of biological ammonia fumigation

Cigar is a new economic growth point of tobacco industry in China in recent years. Root-knot nematode disease seriously infects cigar tobacco in planting. However, the species of pathogenic nematode on cigar tobacco has not been identified so far, and the green control of this disease is rarely reported. In this study, the pathogenic nematode infected cigar tobacco (cultivar: Yunxue 1#) in field of Jiangcheng County, Pu'er City was identified as Meloidogyne javanica based on morphological characteristics of females, males and second-stage juveniles (J2), specific bands of PCR amplification and Koch's rule verification. The effects of fumigating soil with urea release ammonia catalyzed by urease from four edible fungi (Flammulina velutipes, Pleurotus eryngii, Lentinula edodes and Pleurotus cornucopiae) against M. javanica in cigar tobacco were evaluated. The results showed that the minimum concentration of NH₃ needed to kill 100% J2 was 136.8 mg/m3. When the 4 spent mushroom substrates containing 4% urea were respectively mixed with the soil at a mass ratio of 1∶18, and under the conditions of 60% water content, at 28 ℃ for 3 d, the NH₃ concentration released by treatments ranged from 130.9 mg/m3 to 218.7 mg/m3, and generated the control effects ranged from 75.7% to 92.3% to the nematode disease. This results indicated that fumigating soil with "fungus residue+urea" had good application potential in the control of root-knot nematodes in cigar tobacco.