The foliar fungal endophytes of Citrus limon in Argentina

Abstract

Fungal endophytes associated with Citrus limon (L.) Burm., were investigated. Culture of surface-sterilized leaves from two orchards of lemon trees in Tucumán, located in northwestern Argentina, revealed the presence of endophytic fungi in all leaves examined. The colonization frequencies were 69.7% and 72.3% at the two sampled sites, and a total of nine taxa were isolated. Eight of the taxa had relative frequencies of >2% in at least one sample. The number of isolates was significantly lower in the spring. The assemblage composition at each site and sampling time was similar. Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz., responsible for anthracnose, was consistently dominant. Another pathogenic fungus of Citrus spp., Guignardia citricarpa Kiely was also recovered as an endophyte. Scanning electron micrographs of cut uncultured and cultured leaf surfaces, seen in transverse section, showed intercellular fungal hyphae in parenchyma cells No penetration of host cells by either fungus was observed. This is the first report on fungal endophytes in leaves of lemon plants in Argentina.Key words: endophytic fungi, lemon, colonization, scanning electron microscopy.

Endophytic fungi from Vitis labrusca L. ‘Niagara Rosada’) and its potential for the biological control of Fusarium oxysporum

“…Colletotrichum, Diaporthe, Epicoccum, Fusarium, and Guignardia were the dominant genera in the endophytic community from Niagara Rosada leaves (see Table 2). These fungi have also been isolated from various plants from tropical and subtropical regions, including Saccharum sp (Mendes and Azevedo, 2007), Theobroma cacao (Rubini et al, 2005;Hamada, 2006), Musa (Cao et al, 2003), Arachis (Suryanarayanan and Murali, 2006), Euterpe (Rodrigues, 1994), and Citrus spp (Araújo et al, 2001;Durán et al, 2005). Several of the species we isolated have also been found as endophytes of V. vinifera (Medina et al, 2005;Martini et al, 2009) and V. labrusca (Lima, 2010).…”

Enzymatic differences between the endophyte Guignardia mangiferae (Botryosphaeriaceae) and the citrus pathogen G. citricarpa

“…There is an extensive literature describing the molecular and morphological differences that distinguish the two species of Guignardia that inhabit citrus plants (Meyer et al, 2001;Baayen et al, 2002;Bonants et al, 2003;Durán et al, 2005;Everett and Rees-George, 2006;Van Gent-Pelzer et al, 2007). However, there has been no report of the enzymatic aspects associated with species.…”

“…mangiferae has been reported as a ubiquitous endophyte and has been isolated from numerous plants (Baayen et al, 2002). G. citricarpa has a narrower host range, and has been isolated mostly from citrus species (Araújo et al, 2001;Glienke-Blanco et al, 2002;Durán et al, 2005). Besides the wider host range, the geographic distribution of G. mangiferae is also much wider than that of G. citricarpa and remarkably includes regions in which the disease caused by G. citricarpa has not been reported (Everett and ReesGeorge, 2006).…”

Phylogenetic diversity of endophytic leaf fungus isolates from the medicinal tree Trichilia elegans (Meliaceae)

“…In another Meliceae plant, Guarea guidonia, a tropical timber tree, Gamboa and Bayman (2001) observed that over 95% of leaf pieces had endophytes. Other authors working with other plants found isolation frequencies near 95-100% (Durán et al, 2005;Pimentel et al, 2006;Arnold et al, 2007). The leaves used for this work were collected in May, 2007.…”