Blind Seed Disease of Rye-Grass

Abstract

REFERENCE has been made by Wilson, Noble and Gray¹ to the confusion existing in the nomenclature of blind seed disease of rye-grass. The causal organism has been referred to by Hyde² as Pullularia, and the trouble is often referred to as “Pullularia disease”. It seems doubtful whether the conidial form of the causal fungus is Pullularia, and the position is complicated by the occurrence of Pullularia sp. closely associated with the blind seed fungus. Wilson et al.¹ have pointed this out and state that the blind seed fungus and Pullularia sp. may be present on one and the same seed. Our work confirms this; both organisms may be found when examining seed samples. The conidia are distinct; those of Pullularia are smaller in size and yeast-like in character, while those of the blind seed fungus are larger, allantoid, and more regular in size and shape. Whereas Pullularia is usually associated with the glumes and the exterior of the caryopsis, the blind seed fungus only occurs in and on the caryopsis. Pullularia has been isolated from the caryopsis, but not from caryopses surface sterilized before examination. It is always the blind seed fungus which has been obtained in such cases.