Calonectria (Cylindrocladium) species associated with dying Pinus cuttings

Abstract

Calonectria (Ca.) species and their Cylindrocladium (Cy.) anamorphs are well-known pathogens of forest nursery plants in subtropical and tropical areas of the world. An investigation of the mortality of rooted Pinus cuttings in a commercial forest nursery in Colombia led to the isolation of two Cylindrocladium anamorphs of Calonectria species. The aim of this study was to identify these species using DNA sequence data and morphological comparisons. Two species were identified, namely one undescribed species, and Cy. gracile, which is allocated to Calonectria as Ca. brassicae. The new species, Ca. brachiatica, resides in the Ca. brassicae species complex. Pathogenicity tests with Ca. brachiatica and Ca. brassicae showed that both are able to cause disease on Pinus maximinoi and P. tecunumanii. An emended key is provided to distinguish between Calonectria species with clavate vesicles and 1-septate macroconidia.