Existence of Fusarium nygamai in the southern region of Sri Lanka and a key for their characterization

In the course of survey throughout southern region of Sri Lanka during the period 1999-2002, more than 100 isolates of Fusarium nygamai were obtained from a variety of sources including soil and naturally diseased plants. Emphasis is given to cultural features, growth rates, mode of production of micro- and macroconidia, and the presence or absence of polyphialides for the species delimitation. F. nygamai is a relatively newly described species and has never been assigned to any of the sections but it appears to have an affinity with the section Liseola. Therefore, it is proposed that F. nygamai which produces chlamydospores be included in the section Liseola. Hence, the absence of chlamydospores should no longer be a characteristic of the species in the section Liseola. Description and key to the identification of the species are also included.