English

Sandra Da Costa Preisigke,Kelly Lana Araújo,Nayaro Renero Barbosa,Willian Krause,Leonarda Grillo Neves,Milson Evaldo Serafim

doi:10.14393/bj-v31n6a2015-29300

Abstract

Collar rot is a disease difficult to control that has hindered passion fruit cultivation in many regions of Brazil. Therefore, this study aimed to find genetic resistance to the fungus Fusarium solani in Passiflora species using the multivariate analysis methodology to discriminate the most resistant species. The following fourteen Passiflora species were assessed: P. quadrangularis, P. nitida, P. foetida, P. tenuifila, P. alata, P. setacea, P. cincinnata, P. mucronata, P. micropetala, P. suberosa, P. morifolia, P. eichleriana , P. edulis and P. coccinea. These plants were arranged in a casualized block design with 14 treatments (species), three replications and three plants per plot. The reactions of the inoculated species of Passiflora were evaluated with the use of 12 resistance traits. The generalized Mahalanobis distance was used to form groupings by the UPGMA method. 3D projection with the canonical variables and quantification of the relative contribution of characters were also conducted. The UPGMA method revealed the formation of three distinct groups of species, which composed the susceptible, moderately resistant and resistant groups. The groups formed by three-dimensional dispersion were similar to those formed by the dendrogram. The following traits contributed most to genetic diversity: inoculation time until the lesion reached more than 50% of the circumference of the injured stem and area under the curve of the expansion of the lesion width. The use of the set of traits and their joint assessment through multivariate analysis allowed greater accuracy in the inference of the most resistant species, mainly P. nitida and P. cincinnata .

Highlights

Sour passion fruit belongs to the genus Passiflora and is the largest and most important genus of the family Passifloraceae
When the plants reached about ± 30 cm of height, inoculation was performed with the monosporic isolate FS04 from the fungus Fusarium solani from the mycology collection of the University of Mato Grosso (UNEMAT) Plant Genetic Breeding Laboratory, Cáceres campus
It was observed the death of plants of the following species: P. alata, P. suberosa, P. coccinea, P. micropetala and P. setacea

Summary

Introduction

About 70 species produce edible fruits (CUNHA et al, 2002). In addition to its wide variety of passion fruit species, Brazil has emerged, since the 70s, as the world's largest producer of this fruit. A major disease attacking sour passion fruit in most producing states is collar rot, which is caused by the fungus Fusarium solani. This disease significantly reduced productivity and led to constant migration of the culture for pathogen-free regions (FISCHER et al, 2005). The fungus produces abundant resistance structures, the chlamydospores, which are difficult to eradicate from infested areas and difficult to control (FISCHER and REZENDE, 2008)

Objectives

Methods

Results

Conclusion