Abstract
Different varieties of rapeseed (Canola, Raya, Toria. Gobi Sarsoon and Sarsoon) were selected for is~lation of rhizobactcria The potential of these isolates for auxin production was measured in terms of indole acetic acid equivalents by colorimeter method both in the presence and absence of an auxin precursor L-tryptophan (L-TRP). The isolates varied in their potential for auxin production. The highest auxin production (11.4 ug ml,:') in the absence ofL-l'RPwas measured in case ot rhizobactcria (S70) isolated from Raya variety of rape seed. L-Tryptophan application increased the auxin production by these isolates and the highest auxin production in the presence ofL-TRP was also recorded in case of rhizobacteria from the same variety (Raya) but by a different isolate (S78). Key words: auxin. L-tryptophan, rapeseed, rhizobacteria
