Paclobutrazol and Reduced Humidity Improve Resistance to Wilting of Micropropagated Grapevine

Abstract

Plantlets of Vitis vinifera L. `Moscato Bianco' were grown in vitro in cellulose plugs (Sorbarods) saturated with a modified Murashige and Skoog rooting medium. Both the inclusion of 0.5-l mg paclobutrazol/liter in the rooting medium and the use of culture vessels that reduce the relative humidity from 100% to 94% improved resistance of plantlets to wilting after transplanting. Maximum benefit was obtained with a combination of paclobutrazol and reduced humidity; it resulted in smaller stomatal apertures, shorter stems, reduced leaf area, and more and thicker roots. Chemical names used: (2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl) pentan-3-01 (paclobutrazol).