Genetic diversity, mating types and phylogenetic analysis of Indian races of Fusarium oxysporum f. sp. ciceris from chickpea

The present study describes the comparative analysis of five genetic markers viz., random amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus (ERIC), BOX-elements, mating type (MAT) locus and microsatellites for genetic analysis of virulent isolates of Fusarium oxysporum f. sp. ciceri (FOC) representing seven races from chickpea. Phylogenetic analysis of translation elongation factor 1-α and internal transcribed spacer region separated all the FOC isolates into two major clades. Majority of the isolates (FOC 63, FOC 33, FOC 40, FOC 100, FOC 6, FOC 22, FOC 31, FOC 79 and NDFOC 98) representing race 1, 2, 5 and 6 grouped in clade I, while isolates (FOC 90, FOC 108 and FOC 88) belonging to race 3, 4 and 7 were clustered in clade II. Isolates (FOC 33, FOC 40, FOC 17 and FOC 100) representing race 2 had MAT-2 loci, while race 1 isolates (FOC 63, FOC 72 and FOC 76) contained MAT-1 loci only. The principal component analysis (PCA) of RAPD, ERIC, BOX and microsatellite marker data explained 39.94, 39.98, 42.04 and 62.59% of the total variation among test isolates, respectively. Furthermore, there was no correlation existed between genetic diversity, virulence, race compositions or geographic origin of the isolates. Overall, these findings will assist in better understanding of the genetic variability and ideally, will improve disease management practices.本研究针对涵盖鹰嘴豆来源的7个生理小种的尖孢镰刀菌鹰嘴豆专化型（Fusarium oxysporum f. sp. ciceri，FOC）强毒株系的遗传分析，开展了5种遗传标记的比较分析，即随机扩增多态性DNA（random amplified polymorphic DNA，RAPD）、肠杆菌基因间重复共有序列（enterobacterial repetitive intergenic consensus，ERIC）、BOX元件（BOX-elements）、交配型（mating type，MAT）基因座以及微卫星（microsatellites）。通过翻译延伸因子1-α（translation elongation factor 1-α）和内部转录间隔区（internal transcribed spacer region）的系统发育分析，可将所有供试FOC菌株划分为两个主要进化支：多数供试菌株（FOC 63、FOC 33、FOC 40、FOC 100、FOC 6、FOC 22、FOC 31、FOC 79及NDFOC 98）涵盖1、2、5、6号生理小种，聚类于进化支I；而属于3、4、7号生理小种的菌株（FOC 90、FOC 108、FOC 88）则聚集于进化支II。代表2号生理小种的菌株（FOC 33、FOC 40、FOC 17、FOC 100）携带MAT-2基因座，而1号生理小种菌株（FOC 63、FOC 72、FOC 76）仅含有MAT-1基因座。对RAPD、ERIC、BOX及微卫星标记数据进行主成分分析（principal component analysis，PCA）后，分别可解释供试菌株总变异的39.94%、39.98%、42.04%及62.59%。此外，供试菌株的遗传多样性、毒力、生理小种组成及地理来源之间不存在相关性。综上，本研究结果有助于更深入地解析该病原菌的遗传变异，理想情况下可助力优化病害防控实践。