嘎啦苹果抗炭疽叶斑病突变体抗病分子机理研究

Apple Glomerella leaf spot disease caused by Glomerella cingulata was a newly discovered fungal disease, which only infects the apple cultivars with the descent of ‘Golden delicious’, prevailed under high temperature and high moisture conditions, leading to leaf defoliation, malnutrition, low output and low fruit quality. In this proposal, with the material of the Glomerella leaf spot disease sensitive apple cultivar ‘Gala’ and its resistant bud mutation, the sequence mutation between the susceptible and resistant apple genome will be screened out by genome re-sequencing, gene differential expression post inoculation will be analyzed by transcriptome comparison. The candidate resistant genes will be selected and cloned by the combination of re-sequcing, transcriptome analysis and formerly gene mapping results. The resistance gene will be identified from candidate genes by loci sequencing, expression comparison of resistance and susceptible cultivars, over-expression and RNAi depression in transformed apples and its mutant. The molecular mechanism of the apple Glomerella leaf spot disease resistance will be proposed based on the function and their regulation networks of proved resistance genes. The result will provide the theoretical basis for the apple Glomerella leaf spot disease resistance breeding.

苹果炭疽叶斑病是近年发现的重要真菌病害之一，主要危害‘金冠’或具有‘金冠’亲缘关系的苹果品种，在高温高湿条件下引起叶斑症状甚至干枯脱落，造成树体营养不良、果品产量和质量下降。本研究将以‘嘎啦’苹果抗炭疽叶斑病突变体和感病野生型母株为材料，通过基因组重测序查找二者基因组的差异序列；通过炭疽叶斑病菌侵染后的二者叶片转录组比较，筛选差异表达基因；结合基因组重测序、转录组分析以及前期苹果炭疽叶斑病抗性基因定位作图结果，确定并克隆抗病候选基因；通过感、抗病品种间的差异位点比较、基因表达定量、候选基因表达产物平板抑菌试验、过量和抑制表达载体转化嘎啦苹果及其突变体等验证，获得苹果抗炭疽叶斑病基因；并根据该抗病基因功能和表达调控关系探讨苹果炭疽叶斑病抗性的分子机制，从而为苹果抗炭疽叶斑病育种提供理论基础。