Lettuce genotype resistance to "soft rot" caused by Pectobacterium carotovorum subsp. carotovorum

Authors

  • Kátia Cilene da Silva Felix Federal Rural University of Pernambuco; Dept. of Agronomy
  • Willams José de Oliveira Federal Rural University of Pernambuco; Dept. of Agronomy
  • Rosa de Lima Ramos Mariano Federal Rural University of Pernambuco; Dept. of Agronomy
  • Elineide Barbosa de Souza Federal Rural University of Pernambuco; Dept. of Biology

DOI:

https://doi.org/10.1590/0103-9016-2013-0301

Abstract

Soft rot, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc), is the main bacterial disease affecting lettuce (Lactuca sativa L.) crops in Brazil and leads to significant yield losses. This study aimed to assess the reaction of lettuce genotypes to soft rot induced by a virulent isolate and the stability of the resistance to three isolates varying in virulence. Using a descriptive ordinal scale ranging from 1 to 9 a classification system was defined: class 1 = resistant (R): severity (Sev) < 1.5; class 2 = moderately resistant (MR): 1.5 < Sev < 2.5; class 3 = susceptible (S): 2.5 < Sev < 3.5; class 4 = highly susceptible (HS): Sev >; 3.5). Of the 41 tested genotypes, 14 were classified as MR and 27 as S when inoculated with a Pcc isolate of intermediate virulence. Eleven of these genotypes (four S and seven MR) were selected to test their resistance stability against three other isolates with an increasing degree of virulence (Pcc36 < Pcc-A1.1 < Pcc-23). Out of the 11 genotypes eight retained the original classification and three moved from S to MR resistant class when challenged with the least virulent isolate. Vitória de Santo Antão was the only genotype classified as MR for all tested isolates and is a promising candidate for durable soft rot resistance breeding.

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Published

2014-08-01

Issue

Section

Plant Pathology

How to Cite

Lettuce genotype resistance to "soft rot" caused by Pectobacterium carotovorum subsp. carotovorum . (2014). Scientia Agricola, 71(4), 287-291. https://doi.org/10.1590/0103-9016-2013-0301