花生对根结线虫病抗性温室快速鉴定方法

为了通过对花生抗线虫鉴定方法的比较,确定更加快速有效的抗性鉴定技术,作者于2002～2003年在佐治亚大学的Tifton试验站进行了温室盆栽试验.结果表明侵然期幼虫(2000～4000条/株)与虫卵(8000～16000粒/株)均可以用于花生抗线性鉴定的温室接种,但与使用虫卵接种相比,以侵染期幼虫作为接种体需要多花3～5d的时间收集幼虫;接种后14d,可以依据0～5级的虫瘿分级标准将供试的4份花生种质区分开来;接种后6～10周依据卵块数量或每克根中的虫卵数可以进一步确认花生的抗性水平.虫瘿级数、虫瘿数量、卵块数量及每克根中的卵量之间存在着极显著(P＜0.01)的正相关关系.根据研究结果提出了温室中花生抗线虫鉴定的程序方法以8000粒卵/株为适宜接种量,接种后14d依据0～5级的虫瘿分级标准进行初筛,对初筛入选的材料再在接种后6周根据卵块数量或卵量验证其抗性.

Evaluation of Assessment Methods to Rapidly Identify Resistance to Meloidogyne Arenaria in Greenhouse Screening of Peanut

The objectives of this study were to evaluate several methods and develop the more rapid techniques for assessing resistance to M. arenaria in peanut under greenhouse environments. During 2002~2003, two pot trails were conducted in Tifton, Georgia to determine the appropriate screening protocol for identifying resistant genotypes under greenhouse conditions. The results indicated that all of the tested inoculum levels, 2000 J2, 4000 J2, 8000 eggs, and 16000 eggs could be used, however, 8000-eggs inoculum was more suitable to inoculate the peanut plants in greenhouse screening test than the other three inocula. Egg number can be used to substitute the galling indexes to separate the different resistance in peanut two weeks (around 150 degree days) after inoculation. Dependable reductions in nematode reproductions can be identified 6 WAI (about 520 degree days) as well as 10 WAI, based on egg mass index or egg number per gram fresh root. Pearson's correlation coefficients were calculated to compare the galling index systems, gall number, egg mass index, and egg number per gram fresh root for every harvest. Significantly positive correlations (P<0.01) were observed among galling index systems, gall number, egg mass index, and egg number per gram root. We propose a two-stage greenhouse screening protocol to identify peanut genotypes with resistance to the root-knot nematode. A preliminary screen would first be used to eliminate susceptible genotypes based on egg number 14 days (150 degree days) after inoculation with 8000 eggs. The selected genotypes should then be assessed for egg mass index or egg number per gram fresh root at 6 weeks (520 degree days) after inoculation to verify the resistance.