Mycosphaerella graminicola

Mycosphaerella graminicola. Synonym: Septoria tritici. Correct taxonomic name: Zymoseptoria tritici, is a species of filamentous fungus, an ascomycete in the family Mycosphaerellaceae. It is a wheat plant pathogen causing septoria leaf blotch that is difficult to control due to resistance to multiple fungicides. The pathogen today causes one of the most important diseases of wheat. In 2011, Quaedvlieg et al. introduced a new combination for this species: Zymoseptoria tritici (Desm.) Quaedvlieg & Crous, 2011, as they found that the type strains of both the genus Mycosphaerella (linked to the anamorph genus Ramularia) and the genus Septoria (linked to the genus Septoria, an extensive clade of very distinct septoria-like species within the Mycosphaerellaceae) clustered separately from the clade containing both Zymoseptoria tritici and Z. passarini. Since 2011, a total of seven Zymoseptoria species have been described within the genus Zymoseptoria; Z. tritici (the type of the genus Zymoseptoria), Z. Pseudotritici, Z. ardabilia, Z. brevis, Z. passarini, Z. halophila and Z. verkleyi (Named after Gerard J.M. Verkleij, for the contribution that he has made to further the understanding of the genus Septoria). This fungus causes septoria tritici blotch of wheat, a disease characterized by necrotic blotches on the foliage. These blotches contain asexual (pycnidia) and sexual (pseudothecia) fructifications. Asexual state (anamorph, asexual stage was previously named as Septoria tritici): Pycnidiospores are hyaline and threadlike and measure 1.7-3.4 x 39-86 μm, with 3 to 7 indistinct septations. Germiniation of pycnidiospores can be lateral or terminal. Cirrhi are milky white to buff. Sometimes in culture nonseptate, hyaline microspores, measuring 1-1.3 × 5-9 μm, occur outside pycnidia by yeastlike budding. Sexual state (teleomorph): Perithecia are subepidermal, globose, dark brown, and 68-114 μm in diameter. Asci measure 11-14 × 30-40 μm. Ascospores are hyaline, elliptical, and 2.5-4 × 9-16 μm, with two cells of unequal length. Zymoseptoria tritici represents an intriguing model for fundamental genetic studies of plant-pathogenic fungi. It is haploid plant-pathogenic fungus. Many fungi are haploid, which greatly simplifies genetic studies. Zymoseptoria tritici was the first species, in 2002, of the family Mycosphaerellaceae to have a linkage map created. The first report of fully sequenced genome of Zymoseptoria tritici from 2011 was the first genome of a filamentous fungus to be finished according to current standards. The length of the genome is 39.7 Mb, that is similar to other filamentous ascomycetes. The genome contains 21 chromosomes, that is the highest number reported among ascomycetes. Furthermore, these chromosomes have an extraordinary size range, varying from 0.39 to 6.09 Mb.