Evaluation of onion genotypes to slippery skin caused by Burkholderia gladioli pv. Alliicola

Leandro S Velez,Emanuel F Assunção,Matheus S Silva,Carlos Af Santos,Marco Aurélio S Gama,Adriano Márcio F Silva,Elineide B Souza

doi:10.1590/s0102-053620200402

Abstract

ABSTRACT Onion’s (Allium cepa) slippery skin caused by Burkholderia gladioli pv. alliicola is one of the bacterial diseases that stand out in producing regions of the Brazilian Northeast. Given the importance and potential threat of this disease, and the absence of resistant varieties, the aim of this study was to evaluate the reaction of onion genotypes to slippery skin and to analyze the tolerance stability of the most promising genotypes to different strains of the bacteria. Nine strains of B. gladioli pv. alliicola were artificially inoculated in onion bulbs cv. Baia Periforme and the three most aggressive strains (CCRMBG39, CCRMBG172 and CCRMBG212) were selected to evaluate the tolerance to the disease. Fifty-eight onion genotypes were challenged with the most aggressive strain (CCRMBG39) and 34 genotypes were considered as tolerant, with a disease severity varying from 9.79 to 13.42 mm. The fifteen most promising genotypes and the most susceptible genotype were selected to study the stability of tolerance using the three selected strains. The genotypes F2 (EHCEB 20151030 x EHCEB 20133015), Cascuda T5, Crioula Mercosul, Juporanga, EHCEB 20111036, Cascuda T6 and EHCEB 20142028 remained tolerant to the disease when inoculated with the three strains, with a disease severity ranging from 9.13 to 14.19 mm. In view of these results, we conclude that these genotypes can be used as potential sources of tolerance to onion slippery skin.

Highlights

A podridão escorregadia da cebola (Allium cepa) ocasionada pela bactéria Burkhoderia gladioli pv. alliicola é uma das doenças de origem bacteriana que se destaca nas regiões produtoras do semiárido do Nordeste brasileiro
Os genótipos F2 (EHCEB 20151030 x EHCEB 20133015), Cascuda T5, Crioula Mercosul, Juporanga, EHCEB 20111036, Cascuda T6 e EHCEB 20142028 mantiveram-se estáveis quanto a tolerância à doença quando inoculados com os três isolados, apresentando severidade variando de 9,13 a 14,19 mm
Concluímos que esses genótipos apresentaram-se como potenciais fontes de tolerância à podridão escorregadia da cebola

Summary

Introduction

A podridão escorregadia da cebola (Allium cepa) ocasionada pela bactéria Burkhoderia gladioli pv. alliicola é uma das doenças de origem bacteriana que se destaca nas regiões produtoras do semiárido do Nordeste brasileiro. Cinquenta e oito genótipos de cebola foram avaliados utilizando o isolado mais agressivo (CCRMBG39), sendo 34 genótipos considerados tolerantes, com severidade variando de 9,79 a 13,42 mm. Alliicola (Burkholder, 1942), Evaluation of onion genotypes to slippery skin caused by Burkholderia gladioli pv. There are still no onion cultivars that have been proven to be resistant to slippery skin, which could considerably reduce losses caused by this disease (Gava & Tavares, 2016). Considering the potential threat of this disease, research aimed at selection of sources of tolerance to slippery skin which will greatly contribute to increase productivity of the onion crop in the Northeastern semi-arid region of Brazil. This study aimed to evaluate the reaction of onion genotypes to slippery skin caused by B. gladioli pv. This study aimed to evaluate the reaction of onion genotypes to slippery skin caused by B. gladioli pv. alliicola, and to analyze the tolerance stability of the most promising genotypes to different strains of the bacteria

Objectives

Methods

Results