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

Abstract

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.

The Supernatant of a Conidial Suspension of Magnaporthe oryzae Contains a Factor that Promotes the Infection of Rice Plants

“…The spore germination fluid (SGF) was reported to include a ‘susceptibility‐inducing factor’ (Arase et al., 1990; Fujita et al., 1994, 1995), and SGF applied to the leaves of rice induced susceptibility to the non‐host pathogen Alternaria alternata . In addition, Rathour et al. (2002) also reported that M .…”