Francis David M, Kabelka Eileen, Bell Julia, Franchino Barb, St Clair Dina
Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, Wooster 44691.
Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824.
Plant Dis. 2001 Nov;85(11):1171-1176. doi: 10.1094/PDIS.2001.85.11.1171.
Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis causes significant yield losses on tomatoes grown in a humid environment. This study was conducted to identify a source of resistance that could be easily crossed to cultivated tomato and to study the inheritance of resistance. Diverse bacterial strains representative of the major DNA fingerprint classes endemic to North America were used to screen germ plasm and populations derived from wide crosses. Partial resistance to genetically characterized and distinct strains of C. michiganensis subsp. michiganensis was identified in a wild relative of cultivated tomato, Lycopersicon hirsutum Lycopersicon accession (LA)407. The level of resistance in LA407 was not significantly different from that of the resistant L. peruvianum control, LA2157. Resistance from LA407 was recovered in lines from a BC2S4 inbred backcross (IBC) population in both greenhouse and field trials. Linear correlations between field and greenhouse resistance scores were significant, though correlation coefficients tended to be low. Variance components for genetic and environmental variation in resistance were used to estimate broad-sense heritability in the IBC population. These estimates were moderate to high, ranging from 0.34 to 0.85. The number of genes contributing to resistance was estimated from four trials, with most estimates falling in the range of one to three loci. Two lines from the IBC population, IBL 2353 and IBL 2361, were identified as sources that retain resistance in a genetic background that has a theoretical L. esculentum genome content of 87.5%.
由密执安棒形杆菌密执安亚种引起的细菌性溃疡病，会给在潮湿环境中种植的番茄造成严重的产量损失。本研究旨在确定一种易于与栽培番茄杂交的抗性来源，并研究抗性的遗传特性。使用代表北美特有的主要DNA指纹类别的多种细菌菌株，对种质资源以及远缘杂交衍生的群体进行筛选。在栽培番茄的野生近缘种多毛番茄Lycopersicon accession（LA）407中，发现了对基因特征明确且不同的密执安棒形杆菌密执安亚种菌株的部分抗性。LA407的抗性水平与抗性秘鲁番茄对照LA2157的抗性水平无显著差异。在温室和田间试验中，均从BC2S4近交回交（IBC）群体的品系中恢复了LA407的抗性。田间和温室抗性评分之间的线性相关性显著，尽管相关系数往往较低。利用抗性的遗传和环境变异的方差成分，估计了IBC群体的广义遗传力。这些估计值适中至高，范围为0.34至0.85。通过四项试验估计了对抗性有贡献的基因数量，大多数估计值落在一至三个基因座的范围内。IBC群体中的两个品系IBL 2353和IBL 2361被确定为在理论上具有87.5%番茄基因组含量的遗传背景中仍保留抗性的来源。
