Foolad Majid R, Sullenberger Matthew T, Ashrafi Hamid
Department of Plant Science and the Intercollege Graduate Degree Programs in Plant Biology and MCIBS, The Pennsylvania State University, University Park 16802.
Department of Plant Science and the Intercollege Graduate Degree Programs in Plant Biology, The Pennsylvania State University.
Plant Dis. 2015 May;99(5):718-722. doi: 10.1094/PDIS-08-14-0794-RE.
Breeding for disease resistance requires efficient techniques for screening large plant populations. Late blight (LB), caused by the oomycete Phytophthora infestans, is one of the most devastating diseases of tomato (Solanum lycopersicum) worldwide, and there is a great interest in developing cultivars with resistance to this pathogen. Screening for LB resistance is commonly conducted under field or greenhouse conditions using whole plants. In a previous study, we demonstrated correspondence between field and greenhouse screening of tomato for LB resistance. Here, we report the use of a detached-leaflet assay for such screening. Seventy-two genotypes from two tomato species, varying in degree of resistance and susceptibility to LB, were evaluated in two replicated experiments for response to LB in a detached-leaflet assay, and the results were compared with those previously obtained from field and greenhouse screening of the same genotypes. There were significant (P < 0.001) positive correlations between replications (average r = 0.75) and experiments (average r = 0.72), suggesting that the detached-leaflet experiments were consistent. Further, there were significant (P < 0.001) positive correlations between responses in the detached-leaflet assay and those from field (r = 0.82) and greenhouse screenings (r = 0.84), suggesting reliability of the detached-leaflet assay. The results indicate the utility of the detached-leaflet assay for evaluating tomato for LB resistance, which may facilitate screening of large breeding populations.
抗病育种需要高效的技术来筛选大量的植物群体。由卵菌疫霉引起的晚疫病（LB）是全球番茄（Solanum lycopersicum）最具毁灭性的病害之一，因此人们对培育抗这种病原菌的品种有着浓厚的兴趣。晚疫病抗性筛选通常在田间或温室条件下对整株植物进行。在之前的一项研究中，我们证明了番茄晚疫病抗性田间筛选和温室筛选结果具有一致性。在此，我们报告一种用于此类筛选的离体小叶测定法。对来自两个番茄物种的72个基因型进行了评估，这些基因型对晚疫病的抗性和易感性程度各不相同，在两个重复实验中采用离体小叶测定法评估它们对晚疫病的反应，并将结果与之前对相同基因型进行田间和温室筛选所获得的结果进行比较。重复实验之间（平均r = 0.75）以及实验之间（平均r = 0.72）存在显著（P < 0.001）正相关，这表明离体小叶实验具有一致性。此外，离体小叶测定法的反应与田间筛选（r = 0.82）和温室筛选（r = 0.84）的反应之间存在显著（P < 0.001）正相关，这表明离体小叶测定法具有可靠性。结果表明离体小叶测定法在评估番茄晚疫病抗性方面具有实用性，这可能有助于对大量育种群体进行筛选。
