Pithomyces chartarum associated with wheat seeds in Argentina, pathogenicity of two isolates and evaluation of toxigenic ability

PERELLO, ANALIA EDITH; AULICINO, MÓNICA; MARTINELLI, C; REGUEIRA, MELINA; STENGLEIN, S.; MORENO, MR

SPANISH JOURNAL OF AGRICULTURAL RESEARCH

SPANISH NATL INST AGRICULTURAL & FOOD RESEARCH & TECHNOLO

Lugar: Madrid; Año: 2015

1695-971X

In routine surveys of wheat (Triticum aestivum L.) in Buenos Aires province, Argentina, a new disease caused by Pithomyces chartarum (Leptosphaerulina chartarum) was observed in 2012 on seeds of wheat cv. Meteoro. The ITS region was sequenced and analyzed to corroborate the morphological characterization of the fungus. The objectives of the present study were to identify the causal agent, to investigate its pathogenicity in relation to nine wheat cultivars and to identify the secondary metabolites of the fungus. Disease symptoms were different in the different wheat cultivars analyzed in % of seed germination (GG), % of grain discoloration (GD) and % of weakness symptoms of seedlings emerged from infected seeds (WS) suggesting different levels of resistance in wheat against P. chartarum. Particularly ?Meteoro?, ?Buck Guapo? and ?Buck Proteo ? cultivars demonstrated major infection tolerance for GD and WS. In opposite,?Sy 100? and ?Klein Pantera? wheat cultivars were most affected showing weakness, chlorosis of coleoptile, or reduced length, and 50% of necrotic symptoms. P. chartarum isolates produced secondary metabolites including alternariol, alternariol mono-methyl ether, altertoxin I and altertoxine II. The fungus is a new pathogen of wheat in Argentina that can cause diseases on different cultivars as well as produce mycotoxins.