Effects of exogenous BAP, GA3 and ABA on endogenous auxin and rooting of grapevine hardwood cuttings.

摘要

The effects of applications (100 ppm) of BAP [benzyladenine], GA3 and ABA on the root formation of grapevine cv. Muscat Bailey A hardwood cuttings were investigated. BAP suppressed rooting of grapevine cuttings completely, whereas GA3 and ABA inhibited it temporarily. Endogenous IAA in cuttings treated with BAP increased linearly to 12.6 and 19.4 times per cutting and per g FW, respectively, over the control at 30 days after planting. In cuttings treated with GA3, the level of diffusible IAA was higher than that of control cuttings throughout the experimental period; the pattern of fluctuation of extractable IAA was similar to that of the control. In cuttings treated with ABA, the extractable IAA content was significantly lower than that in control cuttings at 10 days after planting. The fluctuation of endogenous IAA in the BAP treated cuttings was different from that seen with the GA3 and ABA treatments. Cuttings treated with BAP presumably failed to root because the level of endogenous IAA wasunbalanced. GA3 may inhibit root formation directly whereas ABA may cause inhibition of rooting by depressing bud activity.