番茄育种种质对南方根结线虫抗性评价及Mi-1基因检测

Resistant Evaluation of Tomato Breeding Germplasms to M.incognita and Detection of Mi-1 Gene

本研究以自育的26份番茄育种种质和抗南方根结线虫番茄品种‘仙客1号’及感南方根结线虫品种‘阿乃兹’为试验材料,采用病土盘栽自然发病鉴定、苗期二龄幼虫人工接种鉴定和PCR扩增及CAPS检测相结合的方法,研究供试材料对南方根结线虫的抗性水平及基因型。鉴定结果表明,供试的28份番茄材料中,高抗17份、抗病6份(包括抗病对照‘仙客1号’)、感病2份、高感3份(包括感病对照‘阿乃兹’),无免疫材料,且病土盘栽鉴定与苗期接种鉴定的结果一致。PCR扩增结果表明,27份番茄材料均能检测到一条750 bp的特异条带;TaqⅠ酶切结果显示,具有酶切位点的22份试材中有15份含纯合显性Mi-1/Mi-1基因、5份含杂合显性Mi-1/mi-1基因、2份含180 bp+250 bp+300 bp三条特异性片段,并且这22份试材对南方根结线虫表现高抗或抗,而其余5份不含显性Mi-1基因的试材则表现高感或感,证明Mi-1是具有抗南方根结线虫能力的基因,分子检测结果与病土盘栽鉴定和苗期接种鉴定的结果吻合率达92.6%;含有180 bp+250 bp+300 bp三条特异性片段的高抗材料可能含有其它抗根结线虫基因。分子检测与抗性鉴定相结合,能为创制抗南方根结线虫新种质提供一种更加省时、省力且经济有效的科学育种方法,可为番茄抗南方根结线虫育种提供理论依据和实践经验。

In this study, total 28 tomato breeding germplasms, including 26 tomato autogeny materials, M. incognita-resistant tomato cultivar‘Xianke No.1’and M. incognita-susceptible cultivar‘Anaizi’, were used to evaluate their resistance to M. incognita by natural incidence in field and artificial inoculation, and detected their genotypes by CAPS, respectively. The results showed that there was no immune material, 17 and 6 （including‘Xianke No.1’） materials were ones of highly resistant or resistant, 2 and 3 （including‘Anaizi’） materials were ones of susceptibility or highly susceptible. The PCR results indicated that 27 tomato materials all include one specific band of 750 bp, after digested by TaqⅠ, and 22 materials with enzyme were highly resistant or resistant to M. incognita, in which 15 and 5 materials carried homozygous dominant Mi-1/Mi-1 genotype and heterozygous dominant Mi-1/mi-1 genotype, 2 materials could be amplified and got 180 bp＋250 bp＋300 bp fragments, while the rest 5 materials without dominant Mi-1 were highly susceptible or susceptible. The results revealed that Mi-1 was an effective resistant gene to M. incognita, and other highly resistant materials with 3 specific bands （180 bp,250 bp, 300 bp） may include other M. incognita-resistant gene should be identified in future. Molecular detection shows that 92.6% of the results match diseased soil planted and artificial inoculation detection. Combining molecular detection with resistance identification provides a time-saving, labor-saving, cost-effective scientific breeding method for creating new anti-M. incognita germplasm, meanwhile it also provides a theoretical basis and practical experience for resistance breeding of tomato against M. incognita in studies.