Written Paper

Seed-Borne Microorganisms of Ethiopian-Grown Soybean and Cickpea Seeds.  [1979]

Alemu Mengistu and J.B. Sinclair(Lecturer and Professor) Ethiopian Journal of Agricultural Sciences [Corporate Author]

Access the full text

Soybean (Glycine max) seeds grown in Ethiopia were bioassayed and 38 fungi plus Bacillus subtilis were identified and found associated with seed lots of 16 cultivars. All but two of the fungi were new records for Ethiopia and 20 were new records for the world. A similar bioassay of 14 lines of chickpea (Cicer arietinum) seeds showed that 10 of the 15 fungi recovered and B. subtilis were new records for Ethiopia and the world. There were 0.02% of soybean seeds examined from the 1973 harvest and 0.04% from the 1974 harvest showing brown mottling similar to that described on soybean seeds from plants infected with soybean mosaic virus. There was a high negative correlation between the percentage germination and occurrence of B. subtilis for both soybean and chickpea. High-yielding soybean (Glycine max) cultivars from the United States and Europe were introduced into Ethiopia in the 1970's to meet the demands for up-grading the peasants diet and to reduce the4 amount of imported soybean flour used for making "Faffa", a children's food. Many of the disease-causing agents of soybean are seed-borne (10, 12, 13). Therefore, it can be expected that diseases underscribed in Ethiopia could be introduced with the seeds of these cultivars. Only a few recorded reports of the occurrence of soybean diseases in Ethiopia, and no comprehensive study, have been made on t he internally seed-borne microorganisms of soybean in the country. The first occurrence of a soybean disea
se in Ethiopia was reported by stewart (14), in 1957,who reported the presence of Pyrenochaeta leaf spot both on Glycine max and a wild species, G. wightii (javanica). Otgher disease-causing micro-oranisms reported in 1967 on soybeans were: Ascochyta app., Macrophomina phaseolina; Mycosphaerella cruenta; Pseudomonas glycinea and Xanthomonas phaseoli var. sojensis (15). Other disease recently observed are: downy mildew (Peronospora manshurica); purple seed stain (Cercospora spp.) and virus-like diseases. Chickpea (Cicer arietinum), the most important pulse crop in Ethiokpia has been cultivated for centuries. There are no reports on seed-borne micro-organisms associated with chickpea seeds grown in Ethiopia. Several fungi and a nematode have been reported associated with chickpea plants in the field: Fusarium oxysporum f. ciceri; Leveillula taurica; Sclerotium rolfsii and Meloidogyne spp. (15) We report on fungi and bacteria associated with soybean and chickpea seeds grown in Ethiopia in 1973 and 1974. Some of the genera are first reports.

From the journal

Ethiopian Journal of Agricultural Sciences