Reaction of maize inbred lines to the bacterium Pantoea ananas isolated from Phaeosphaeria leaf spot lesions

Abstract

A leaf spot disease in maize has been reported throughout all corn producing areas in Brazil, and its incidence and severity have increased significantly. Initial symptoms are characterized by the development of dark green water-soaked leaf spots, which later turn into straw-colored necrotic lesions. Some authors associated the symptoms of this disease to those of the disease Phaeosphaeria Leaf Spot caused by fungus Phaeosphaeria maydis (f. imperf. Phyllosticta sp.). However, we reported in previous works the involvement of a bacterium, the Pantoea ananas (syn. Erwinia ananas) as the initiator agent this disease. The aim of this work was to evaluate the behavior of corn genotypes when inoculated with P. ananas in the greenhouse. The results reinforced those previously obtained that showed the role of the bacterium as the initiator agent of the disease.

Pantoea ananatis: an unconventional plant pathogen

“…They are selected in a cutting production nursery where the incidence of disease is high. Similarly, in a study by Paccola‐Meirelles et al . (2002), it was discovered that, by artificially inoculating maize lines, it was possible to select genotypes resistant to P. ananatis .…”

“…They are selected in a cutting production nursery where the incidence of disease is high. Similarly, in a study by Paccola-Meirelles et al (2002), it was discovered that, by artificially inoculating maize lines, it was possible to select genotypes resistant to P. ananatis. The control of white spot disease of maize in Brazil has also been achieved by applying the fungicide Mancozeb in the initial phases of disease development (Bomfeti et al, 2007).…”

Detecting the Early Stage of Phaeosphaeria Leaf Spot Infestations in Maize Crop Using In Situ Hyperspectral Data and Guided Regularized Random Forest Algorithm

“…Typically, lesions are scattered over the leaf surface and have a chlorotic appearance [9,13]. These turn to pale green, straw-colored, bleached and necrotic, or dried with dark brown margins [9,13]. Under favourable conditions, these lesions may coalesce to large irregular shapes and blight the entire leaf, in some cases infecting the stem [6].…”

Eficiência de Fungicidas para o Controle da Mancha Branca do Milho

“…Segundo Amaral et al, (2005), sintomas semelhantes aos da mancha branca são causados por vários fungos fitopatogênicos, sendo os principais Phyllosticta sp., Phoma sorghina e Sporormiella sp. -Meirelles et al (2001-Meirelles et al ( , 2002 Krawczyk et al, 2010;Lanza, 2009;Pérez-Terrón et al, 2009;Bomfeti et al, 2008;Paccola-Meirelles et al, 2001). Goszczynska et al (2007) (Cota et al, 2010;Kido et al, 2008;Yan et al, 2008;Coutinho et al, 2002;Azad et al, 2000;Azegami et al, 1983;Gitaitis & Gay, 1997) Os sintomas da doença são caracterizados pela formação de lesões inicialmente circulares, aquosas e verde claras (anasarcas).…”

“…Em geral, os sintomas surgem nas folhas inferiores, progredindo rapidamente para a parte superior das plantas. Os sintomas são mais evidentes e severos na fase reprodutiva das plantas e as lesões variam em tamanho de acordo com a resistência do material (Costa et al, 2010;Paccola-Meirelles et al, 2002). Sob condições de ataque severo, os sintomas da doença podem ser observados também na palha das espigas, podendo causar seca prematura das folhas e redução no ciclo da planta, no tamanho e no peso dos grãos (Oliveira et al, 2004).…”