香蕉枯萎病菌热带4号小种对番茄等3种模式植物的致病性分析

The Pathogenicity of Fusarium oxysporum f.sp. cubense Tropical Race 4 on Three Model Plants

香蕉遗传转化体系效率低,难以满足大量鉴定基因的抗性功能的要求。为了借鉴模式植物成熟的遗传转化再生体系,对拟南芥、烟草、番茄3种模式植物的多个常用品种材料对强毒性香蕉枯萎病菌热带4号小种的敏感性进行评价。结果表明,仅番茄‘Money Maker’品种受侵染后表现出典型的枯萎病症状;从感病植株根颈附近茎段内部坏死组织可检测和再次分离出病原菌,说明病菌的致病性符合柯赫氏法则(Koch’s Rule)。进而以子叶为外植体建立了高效的Money Maker番茄不定芽再生体系。研究结果为借助模式植物番茄进行快速筛选鉴定抗香蕉枯萎病功能基因奠定了基础。

Nowdays,Fusarium wilt greatly threatens the banana industry world wide. Genetic improvement is a promising method for the breeding of disease resistant cultivars. However,currently,this method is limited due to the lack of resistant genetic resources. At present,the low efficiency of generation of transgenic banana plants and the lack of knowledge of molecular biology make it difficult to characterize defense-related genes in large-scale. A good strategy is to refer the advance tools and progresses applied and achieved in the studies of model plants. Therefore,in this study,three model plant species,i.e.,Arabidopsis thaliana,tobacco and tomato,each with several popular ecotypes,were applied to test their susceptibility to Fusarium oxysporum Schlecht. f. sp. cubense tropical race 4（Foc TR4）. Our results demonstrated that,after inoculated with Foc TR4,typical disease symptoms only could be observed on the tomato Money Maker. Moreover,Foc TR4 could be detected and re-isolated from the discolour tissue of pseudostem near the roots of infected tomato plants, which confirmed that the whole pathogenicity was in conformity with the Koch＇s Rule. A regeneration system with high efficiency was also developed for producing adventitious shoots from cotyledon of Money Maker. These results therefore lay the foundation for rapid screening genes with resistance to Fusarium wilt,via using a model plant as material.