Grass endophyte researches 3:a new grass-endophyte association developed from Calamagrostis sp. and Neotyphodium sp. producing stromata without sexual spores

In May 2006,we observed stromata producing gramineous plants in the Southern Suburb Nanjing.Stromata surrounded the flag leaf sheathes,white,as long as 47.5-165.0 mm.From its appearance in late April until crash in middle July,no mature sexual structures were either observed in nature or conducted by artificial mating tests.These plants were upstanding and 90-120 cm in height with aggressive stolons,but did not produce inflorescences during the two heading periods.Mainly based on morphology,leaf epidermis micromorphology and rDNA-ITS phylogenetic analysis,the non-flowering host plant was identified as Calamagrostis sp..Twenty-nine plants with stroma and 87 plants without stroma collected were detected to be all infected by endophytes,and 20 fungal isolates were isolated and selected from these samples.Basing on the morphological properties of asexual structures,the isolates were identified as Neotyphodium sp..The botanical properties of the host plant and the endophyte stromata without sexual structures indicate that this symbiotum should be a brand new host-endophyte association.This combination is the 3rd example on the development of sexual structure non-producing stromata,and more surprisingly,the host plants of all the 3 such examples came out from tribe Agrostideae.