Lorenzini Marilinda, Zapparoli Giacomo
Dipartimento di Biotecnologie, Università degli Studi di Verona, strada Le Grazie 15, 37134 Verona, Italy.
Dipartimento di Biotecnologie, Università degli Studi di Verona, strada Le Grazie 15, 37134 Verona, Italy.
Int J Food Microbiol. 2014 Sep 1;186:1-5. doi: 10.1016/j.ijfoodmicro.2014.06.008. Epub 2014 Jun 17.
Alternaria is a fungal agent of grape bunch rot which occurs during withering, a process which produces passito style wines. Seven isolates of Alternaria spp. were characterized using morphological examination, genotypic analysis and pathogenicity. Six of these isolates produced conidiophores and conidia displaying sporulation patterns typical of the Alternaria alternata species-group. Variability in colony morphology and growth on different media was observed. Phylogenetic analysis of internal transcribed spacer (ITS) sequences clustered all isolates within a monophyletic clade, while intergenic spacer region (IGS)-RFLP profiles were congruent with those of A. alternata and Alternaria arborescens. RAPD-PCR proved helpful in discriminating between strains. To assay strain pathogenicity, grape berries were infected while undergoing withering conditions at different temperatures. Disease capacity was found to be strain dependent and varied consistently between the most and least aggressive strains. This study has provided interesting information on polymorphism within Alternaria spp. populations in withered grapes and on understanding the saprophytic role of this fungus during the post-harvest dehydrating process.
链格孢属真菌是葡萄串腐病的病原体，该病在萎蔫过程中发生，萎蔫过程会酿造出帕西托风格的葡萄酒。使用形态学检查、基因型分析和致病性研究对7株链格孢属菌株进行了鉴定。其中6株菌株产生的分生孢子梗和分生孢子呈现出链格孢菌种组典型的孢子形成模式。观察到不同培养基上菌落形态和生长情况的差异。对内部转录间隔区（ITS）序列进行的系统发育分析将所有菌株聚集在一个单系分支内，而基因间隔区（IGS）-RFLP图谱与链格孢和树状链格孢的图谱一致。RAPD-PCR被证明有助于区分不同菌株。为了测定菌株的致病性，在不同温度下萎蔫的葡萄浆果上接种了菌株。发现致病能力因菌株而异，在最具侵袭性和最不具侵袭性的菌株之间始终存在差异。本研究提供了关于萎蔫葡萄中链格孢属菌种种群内多态性以及了解该真菌在采后脱水过程中腐生作用的有趣信息。
