基于表型症状和实时定量PCR鉴定不同香蕉品种对枯萎病的抗病性

摘要

[Objective] Fusurium wilt was one of the most crucial constrain factors for sustainable development of banana industry.Developing a rapid evaluation methodology for TR4 resistance with different banana varieties in greenhouse would provide a basis of resistant variety screening and further variety improvement for TR4 resistance in the field trial.[Method]In order to identify resistant differences among tested materials against Fusarium wilt and screen the reliable resistant resources for future variety improvement,Baxi,Guijiao No.1 and our selected line Yunjiao No.1 were evaluated in the green house by the disease index survey in leaf symptom,stem dissection,real-time quantitative PCR after inoculation with Fusarium oxysporum f.sp.cubense Tropic Race 4 (Foc TR4) wild isolate (15-1)to plant roots.[Resuh]Yunjiao No.1 had the best performance among the three banana varieties at 25 and 45 days after pathogen inoculation in three experiments.The overall performance related to TR4 resistance from strong to weak was:Yunjiao No.1 ＞ Guijiao No.1 ＞ Baxi.The pathogen content of the inoculated soil had no significant difference among different banana varieties planted.The pathogen content in the corm of the Yunjiao No.1 was low and showed significant different from that in Bard (P ＜ 0.05),however,it showed no significant difference with that in Guijiao No.1.[Conclusion] By the rapid evaluation methodology for TR4 resistance with different banana varieties in greenhouse,we found Yunjiao No.1 had the best tolerance compared with the other two varieties,and it deserved field selecting.%[目的]香蕉枯萎病已成为香蕉产业可持续发展的最主要限制因素之一,通过室内建立不同香蕉品种对枯萎病快速鉴定方法,为大田香蕉抗病品种鉴定和品种改良提供依据.[方法]本研究对巴西蕉(B)、桂蕉1号(GV)和笔者自主选育的品系云蕉1号(Y)进行枯萎病病菌4号生理小种热带型(Fusarium oxysporumf.sp.cubense Tropic Race 4,Foc TR4)野生型菌株(15-1)温室接种,通过叶片表型和球茎解剖2种病情指数调查并结合实时定量PCR分析,鉴定供试材料的抗感差异并筛选出对枯萎病抗性较好的香蕉材料.[结果]经过3次独立温室接种试验,结果显示云蕉1号病情指数最低,其他品种在接种后枯萎病抗性强弱的表现为Y＞GV＞B.检测接种后土壤中病原菌含量发现,3个品种之间未达到显著性差异,表明接种条件相对一致.不同香蕉品种在接种25 d后,云蕉1号的球茎病原菌含量较低,与巴西蕉相比达到了显著性差异(P＜0.05),但是与桂蕉1号差异不显著,说明云蕉1号抗病性较好.[结论]本研究通过香蕉枯萎病的室内速鉴定方法表明,云蕉1号对枯萎有较好的耐病性,适合进一步大田筛选.