【作者】 刘纪霜；

【导师】 刘志明； 张君成；

【作者基本信息】 广西大学 ， 植物病理学， 2007， 硕士

【摘要】 从广西柳州市融安县、桂林市永福县和南宁市罗汉果苗圃等地采集的罗汉果根结线虫病病根及根际土壤，分离到成熟雌虫、雄虫、幼虫和卵，经形态学特征鉴定有2个种，分别为南方根结线虫[Meloidogyne incognita(Kofoid and White，1919)Chitwood，1949]和爪哇根结线虫[Meloidogynejavanica(Treub，1885)Chitwood，1949]，其中南方根结线虫为优势种群。温室人工接种条件的优化试验结果表明：罗汉果接种二龄幼虫1000头／株、或者接种卵1000粒／株、或者接种病土(含二龄幼虫为41头／100mL土)2000mL／株，3者均为最佳接种虫体数量；罗汉果幼苗6叶期接种根结线虫为最佳接种苗龄；罗汉果接种根结线虫的最佳月均温在25.5～30.5℃。在田间对12个罗汉果品种进行抗南方根结线虫病的筛选鉴定，得到11个中抗品种和1个轻感品种；在温室用盆栽法对21个罗汉果品种进行抗南方根结线虫病的筛选鉴定，得到5个中抗品种、10个轻感品种和6个中感品种。测定了罗汉果不同抗性品种被南方根结线虫侵染后，过氧化物酶活性的变化，结果发现：轻感品种18号野生青皮果接虫与不接虫相比，过氧化物酶的活性提高4.22个单位；中抗品种19号野生红毛果和23号长滩果接虫与不接虫相比，过氧化物酶的活性提高11.17和25.71个单位。表明抗病品种的过氧化物酶活性提高的幅度更大。用离体测定法测定了罗汉果根系分泌物对南方根结线虫卵孵化的影响，结果发现：用根系分泌物处理后第4d，中感品种cd-7、中抗品种野生红毛果和蒸馏水对照处理的平均孵化量分别为37.3头、24.3头、11.7头。cd-7、野生红毛果和蒸馏水处理的卵孵化高峰分别在第6d、8d、8d。表明罗汉果根的分泌物对卵的孵化有不同程度的促进作用。更多还原

【Abstract】 Mature females, males, juveniles and eggs of root-knot nematode were isolated fromthe infected roots and rhizosphere of Luohanguo (Siraitia grosvenorii) which colletedfrom Louzhou, Guilin, Nanning of Guangxi. Two species were identified as Meloidogyneincognita and Meloidogyne javanica based on morphological characters, M. incognitawas the dominant specie.Condition optimization assay for inoculation of M. incognita on host Luohanguowere conducted at greenhouse. Results indicated that the optimal quantity of M.incognita was 1000 second-stage juveniles (J2)/plant, or 1000 eggs/plant, or 2000 mLinfected soil/plant(contained 41 J2 in 100 mL soil), the optimal inoculation period wassix-leaf stage of Luohanguo seedling, the optimal monthly mean temperature for diseaseinfection was 25.5～30.5℃.12 Luohanguo varieties were evaluated on resistance to M. incognita in the field. 11varieties were moderate varietie and 1 variety was slightly susceptibility to M. incognita;21 Luohanguo varieties were evaluated on resistance to M. incognita at greenhouse, 5varieties were moderate resistance, 10 varieties were slightly susceptibility and 6varieties were moderate susceptibility to M. incognita.POD activity of Luohanguo after inoculation of M. incognita was determined. PODactivity of susceptible variety Yeshengqingpiguo was increased by 4.22 unit, PODactivity of resistant variety Yeshenghongmaoguo was increased by 11.17 unit, PODactivity of resistant variety Changtanguo was increased by 25.17 unit. Results indicatedthat POD activity of resistant variety increased more than that of susceptible variety.Effects of root exudates of Luohanguo on eggs hatch of M. incognita weredeterminated by experiment in vitro. On fourth day after treatment of root exudates, mean eggs hatching quantity was 37.3, 24.3, and 11.7 for variety cd-7 (with moderatesusceptibility), variety Yeshenghongmaoguo (with moderate resistance), and distilledwater respectively. Hatching peak of the eggs was on 6th day, 8th day, and 8th day aftertreatment of root exudates for variety cd-7, variety Yeshenghongmaoguo, and distilledwater respectively. Results indicated that root exudates enhanced the eggs hatch indifferent degree.更多还原