Fusarium solani f. sp. passiflorae: a new forma specialis causing collar rot in yellow passion fruit

Abstract

The aim of this study was to characterize a Fusarium population obtained from yellow passion fruit (YPF) with collar rot using pathogenicity, morphocultural characteristics and molecular tests. Pathogenicity and disease severity were assessed in six plant species: YPF, zucchini, tomato, bean, soya bean and cucumber. Potato dextrose agar medium (PDA) was used to determine mycelial growth at five temperatures (15-35°C). The colour produced by isolates was also determined on PDA at 25°C. Synthetic nutrient agar medium was used to evaluate: (i) type of mycelium and phialides; (ii) size, shape and number of septa from conidia; and (iii) production of chlamydospores and perithecia. Molecular tests consisted of sequencing the ITS-5Á8S rDNA region and elongation factor 1a (EF-1a) gene. The isolates caused large lesions on YPF, zucchini and tomato, with YPF having the highest mean disease severity and being the only one that showed wilt symptoms and death of the plant. Thus the isolates showed host specificity. Maximum mycelial growth occurred at 25°C and the predominant colour was bluish-white. The isolates produced long phialides, dense aerial mycelium, oval microconidia with a mean size of 9Á5 9 2Á6 lm, macroconidia of 32Á7 9 3Á4 lm with 3Á3 septa, and chlamydospores; only one isolate lacked perithecia. Phylogenetic trees of the ITS region and EF-1a gene showed that isolates from YPF formed a distinct group within the F. solani group and the formae speciales of F. solani. It is proposed to name all isolates from YPF as F. solani f. sp. passiflorae.

Molecular and Aggressiveness Characterization of Isolates of Fusarium solani and Fusarium oxysporum f.sp. passiflorae Associated to Passion Fruit Wilting

“…In this same context, using the ITS-5.8S region sequencing and the elongation factor 1α (EF-1α). Bueno et al (2014) verified an interspecific variability of eight F. solani isolates from P. edulis. The authors identified that the isolates had host specificity and that the phylogenetic trees of the ITS and EF-1a region showed that the isolates formed a distinct group within the F. solani group when compared to other GenBank sequences.…”

Water relations, photosynthetic capacity, and growth in passion fruit (Passiflora edulis Sims f. flavicarpa Deg.): seedlings and grafted plants

“…One of the main diseases affecting yellow passion fruit is the collar rot caused by the fungus Fusarium solani (Fischer & Rezende, 2008). This disease has already been reported in Passiflora edulis, P. edulis f. flavicarpa, P. alata, P. ligularis, P. maliformis, and P. quadrangularis (Fischer & Rezende, 2008), causing a decrease in yield and the continuous migration of the crop to pathogen-free regions (Bueno et al, 2014).…”

Population Structure and Development of Resistance to Hymexazol Among Fusarium solani Populations from Date Palm, Citrus and Cucumber

“…; Bueno et al. ). In Oman, F. solani is a widespread pathogen that causes wilt of cucumber ( Cucumis sativus ), dieback of acid limes ( Citrus aurantifolia ) and root diseases of date palm ( Phoenix dactylifera L.) (Al‐Sadi et al.…”

“…In addition, it can be an opportunistic pathogen and cause superficial mycoses in humans and animals (Tuxbury et al 2014). Fusarium solani causes different types of diseases such as wilt, slow decline and fruit rot (Al-Sadi et al 2011b;Bueno et al 2014). In Oman, F. solani is a widespread pathogen that causes wilt of cucumber (Cucumis sativus), dieback of acid limes (Citrus aurantifolia) and root diseases of date palm (Phoenix dactylifera L.) (Al-Sadi et al 2011b, 2012b).…”