Elucidation of the Disease Cycle of Olive Anthracnose Caused byColletotrichum acutatum

Abstract

Anthracnose, caused by Colletotrichum acutatum and C. gloeosporioides, is a major fungal disease of olive in many countries. In Spain, the disease has been associated only with a characteristic rot and mummification of mature fruit. The purpose of this study was to determine whether C. acutatum could infect other plant tissues that may serve as sources of inoculum for anthracnose epidemics. Inoculations of young plants or detached leaves and field observations demonstrated that flowers and immature olive fruit are susceptible to the pathogen. Flower infection caused blight of inflorescences and infection of developing fruit. Immature fruit were infected in all phenological stages, although infection remained latent for 7 to 8 months, until the onset of fruit ripening. Fruit susceptibility increased and latent period decreased with maturity. Fruit were required for symptom development on inoculated plants. Plants without fruit were infected but they did not show any disease symptoms. Only plants with rotten fruit developed leaf wilting and branch dieback symptoms several weeks later. These results, together with the low level of pathogen isolation from affected leaves and branches and the toxicity of sterile fungal extracts to olive cuttings, suggest that a toxic substance produced by C. acutatum in rotten fruit may account for this syndrome. Both disease syndromes, fruit rot and branch dieback, developed in several olive cultivars, which were equally susceptible to the pathogen. However, olive cultivars differed in their response to flower and fruit infection. Latent infection of developing fruit during the spring may permit survival of the pathogen during the hot and dry summer and serve as an inoculum source for anthracnose epidemics that develop on ripening fruit in autumn.

Fruit rot on olive caused by Pilidium concavum in Iran

“…Diverse fungal groups have been reported to cause fruit rot on olive, including species of Botryosphaeriaceae such as Botryosphaeria, Diplodia, Lasiodiplodia, Macrophomina, Neofusicoccum and Camarosporium; Glomerellaceae including Colletotrichum; Mycosphaerellaceae incl. Pseudocercospora and several other fungal species with minor importance such as Fusicladium oleagineum, Alternaria spp., Aureobasidium pullulans, Epicoccum nigrum, Cladosporium herbarum s.l., Capnodium elaeophilum and Truncatella angustata (Avila et al 2005;Athar 2005;Chattaoui et al 2011;Moral et al 2008Moral et al , 2009Sergeeva et al 2009;Arzanlou et al 2012). In the present study we report a new fruit rot fungal disease on olive in Iran.…”

“…In recent years, there is growing interest by government and local authorities in establishing new olive orchards in different provinces of the country; thus current trends are for acreage increase and planting new varieties in different parts of the country (Noormohammadi et al 2007). The olive plants are susceptible to numerous debilitating diseases which limit olive production in many olive-producing countries and also in Iran (Lazzizera et al 2008;Moral et al 2009). Fungal diseases cause significant economic losses to the olive industry through yield loss, reduction in growth, and increase in production costs (Lazzizera et al 2008;Moral et al 2009).…”

“…The olive plants are susceptible to numerous debilitating diseases which limit olive production in many olive-producing countries and also in Iran (Lazzizera et al 2008;Moral et al 2009). Fungal diseases cause significant economic losses to the olive industry through yield loss, reduction in growth, and increase in production costs (Lazzizera et al 2008;Moral et al 2009). Several fungal diseases such as Verticillium vascular wilt, peacock eyespot and fruit rot diseases have been reported on olive in Iran (Ershad 2009;Arzanlou et al 2012).…”

La Antracnosis del olivo y su efecto en la calidad del aceite

“…savastanoi; y sobre todo las enfermedades fúngicas Repilo, causada por Spilocaea oleaginea; Emplomado, causada por Pseudocercospora cladosporioides; y la Antracnosis o Aceituna jabonosa, causada por varias especies del género Colletotrichum. Mundialmente, la Antracnosis es la enfermedad más importante de la aceituna (Andrés, 1991;Trapero y Blanco, 2008;Moral et al, 2009c;Cacciola et al, 2012) y, sin duda alguna, la enfermedad que causa un mayor deterioro de la calidad del aceite (García, 1995;1998;García et al, 1997a;Iannotta et al, 1999;Mincione et al, 2004;Carvalho et al, 2008).…”

Infection Process of Olive Fruits by Colletotrichum acutatum and the Protective Role of the Cuticle and Epidermis

“…The Colletotrichum acutatum and C. gloeosporioides caused anthracnose in a wide range of hosts found mainly in temperate, subtropical and tropical areas (Martín and García-Figueres, 1999;Moral et al, 2009). Talhinhas et al, (2005) with molecular and phenotypic assays reported that the occurrence of C. acutatum in Portuguese olive orchards was higher (>97%) than C. gloeosporioides (<3%).…”