Rice leaf pathogenic fungi on wheat, oat, Echinochloa phyllopogon and Phragmites australis.

Abstract

Pathogenic fungi that infect rice also infect a range of other plants. The mycoflora on a number of these plants in Morocco was studied. Echinochloa phyllopogon and Phragmites australis are two weeds adapted to rice fields. Wheat is often grown in rotation with rice, and common oat is an adventitious specie common in wheat fields. Fungi found in these plants were of two types: 1. True rice pathogens: Pyricularia grisea, Helminthosporium oryzae, H. sativum, H. australiensis, H. spiciferum and Curvularia lunata and 2. Saprophytes that cause rice discoloration: Trichoderma harzianum, Alternaria alternata, Nigrospora oryzae, Epicoccum nigrum, Fusarium moniliforme, Cladosporium herbarum and Trichothecium roseum. Seed discoloration also induces a weak germinative power of the paddy and lowers market value and yield at the manufacturing stage. Among these latter fungi, T. harzianum, A. alternata and F. moniliforme can be used to control foliar diseases caused by the true rice pathogens. This is the first report of Helminthosporium oryzae on wheat and oat in Morocco. The study also found that the pathogenic fungi P. grisea, H. oryzae and H. sativum isolated from wheat, oat, Echinochloa phyllopogon and Phragmites australis are strongly pathogenic when inoculated on rice.