Host Species-Specific Protoplast Damaging Activity of Spore Germination Fluids of Blast Pathogen Magnaporthe grisea

The effect of spore germination fluids (SGFs) of rice and ragi (Eleusine coracana) limited forms of Magnaporthe grisea was studied on the protoplasts of host and non-host species to determine their host specificity. The concentrated SGFs of rice strain of M. grisea exhibited strong disruptive activity against the protoplasts of two rice cultivars, Fukunishiki and Caloro, but had little effect on the protoplasts of ragi cv. VL 17 and Podophyllum hexandrum. However, the SGFs of ragi strain of M. grisea showed a high tendency to disrupt ragi protoplasts but inflicted less damage on protoplasts of the two rice cultivars and P. hexandrum. These results suggest that SGFs of M. grisea contain some factor(s) which exhibit host species-specific activity and may be the determinants of basic compatibility.