Influence of pH on the biology of <i>M. oryzae</i>.

<p>(a) The wild type strain Guy11 was grown for 14 and 21 days on solid rice medium buffered to pH 5 (grey) or to pH 8 (black) and conidia from one 9 mm plate were collected and counted under a microscope; Student test analysis of the data revealed a Pvalue of 0,004 at 14 days and of 0.07 at 21 days, due to higher variance. (b) One hundred conidia collected from cultures on non-buffered solid rice medium were incubated for 8 hours in water adjusted to pH 3 to 8, and their germination was monitored by microscopic observation of the presence of a germ tube at least 3 µm in length. (c) Conidia collected from cultures on solid rice medium buffered to pH 5 (grey) or pH 8 (black) were sprayed onto rice or barley plants, and the lesions on 10 separate leaves were counted after 5 days of incubation; Student test analysis of the data revealed a Pvalue of 0.078 for the barley experiment and of 0.079 for the rice experiment. All experiments were run in triplicates and standard deviations are shown.