Interactions between a vesicular-arbuscular mycorrhizal fungus (Glomus intraradices) and Streptomyces coelicolor and their effects on sorghum plants grown in soil amended with chitin of brawn scales

The effect of the interaction between a vesicular-arbuscular (VA)-mycorrhiz a (Glomus intraradices no. LAP8) and Streptomyces coelicolor strain no. 238 9 on the growth response, nutrition and metabolic activities of sorghum (So rghum bicolor) plants grown in nonsterilized soil amended with chitin waste was studied in a greenhouse over 8 weeks. Chitin amendment resulted in an increase in the microbial population and chitinase activity in soils. Growt h of mycorrhizal G. intraradices no. LAP8 and non-mycorrhizal sorghum plant s increased as compared with other treatments either in the presence or abs ence of S. coelicolor strain 2389. VA-mycorrhizal inoculation significantly increased the growth, photosynthetic pigments, total soluble protein and n utrient contents of sorghum compared to non-mycorrhizal sorghum. Such incre ases were related to increased mycorrhizal colonization. Inoculation with S . coelicolor 2389 significantly increased the intensity of mycorrhizal root colonization and arbuscular formation, but the levels of mycorrhizal infec tion and their beneficial effects were significantly reduced with the addit ion of chitin waste to the soil. Analysis of the content of total amino aci ds and ammonia in leaves on the basis of dry matter production showed that, in most instances, total amino acids of mycorrhizal plants were significan tly higher than those of non-inoculated plants. The microflora of the rhizo sphere was highly affected by mycorrhizal inoculation. Quantitative changes in acid and alkaline phosphatase activities of the roots in response to th e mycorrhizal inoculation are discussed.