Studies on the Rhizosphere Microflora of Sorghum in Relation to Hydrocyanic Acid Content of Roots

Abstract

Analysis of hydrocyanic acid contents of the roots of six sorghum strains revealed the concentration to be high in the seedling, and that it reduced with age. I-Iydrocyanic acid was also present in the roots of yatoon plants but in lower concentrations than in seed plants of the same s t r a~n . IChizosphere erfects on the ~nicrobial populations a t different stages of plant growth mere obser\.ed and the effect varied with the strain and age of plant. The rhizosphere:soil (R:S) ratio for bacteria ranged from 1 to 2.5, for fungi 1 to 17, and for actinomycetcs 1 to 6. The rhizosphere eifect co~itinued in the ratoon plants in all strains, thougll to a lesser extent than in seed plants. Statistical analysis of the data for corrclatio~l between hyclrocyanic acid concentration in roots and the population of rhizosphere microorganisms did not indicate any uniform erfect in all the sorghu~n strains.

Microorganisms and cyanide.

“…Rangaswami and Balasubramanian (134,135) analyzed the cyanide content ofthe roots of six varieties of sorghum: in each case the cyanide content was high in seedlings but reduced somewhat with age. As with non-cyanogenic plants, there was a distinct rhizosphere effect; VOL.…”

Produção de proteína fúngica em raiz e folha de mandioca (>i<Manihot esculenta>/i< Crantz)

“…[ possível que a linhagem selvagem isolada de raiz maa dioca, utilizada anteriormente, fosse adaptãve1 a diversos meios de cultura. , 1936;YOUATT, 1954;WARE e PAINTER, 1955;RANGASWAMI e BALASUBRAMANIAN, 1963;STROBEL, 1964STROBEL, , 1966STROBEL, e 1967DUN-NILL e FOWDEN, 1965;FLOSS et alii, 1965;ALLEN e STROBEL, 1966;STAFFORD e CALLELY, 1969;CASTRIC e STROBEL, 1969;BRYSK e RESSLER, 1970;MUNDY et alii, 1973;e KNOWLES, 1976) ou para sinteses de vitamina B 12 (TRELAWNY et a1ii, 1956) ou, ainda, que seja capaz de produzir as enzimas necessãrias ã respiração cianeto-resistente (MIZUSHIMA et a1ii, 1959;MIZUSHIMA et a1ii, 1960;SKOW-RONSKI e STROBEL, 1969;MCFETERS et alii, 1970;LAMBOWITZ e SLAYMAN, 1971 ; WESTON et alii, 1974;ASHCROFT e HADDOCK, 1975;NIVEN et alii, 1975;e KNOWLES, 1976). Possivelmente o micêlio com nücleo ha-plÕide, utilizado como inõculo, perdeu a capacidade de realizar uma ou mais destas atividades, as quais são pré-requisitos para o processo de desintoxi cação do cianeto.…”