Influence of some factors on rooting of pear rootstock in vitro

Abstract

Factors that affect shoot rooting of pear tree Pyrus calleryana were studied. Shoot tips 1 cm long were placed in "MS" medium, pH 5.7 and 7 g L^-1 of agar plus NAA and IBA at concentrations of 0.1, 1.0 and 5.0 mg L^-1 and some time later IBA at concentrations of 0.0, 0.125, 0.250, 0.500, and 1.0 mg L^-1. Finally several salt concentrations (1/3, 1/2, and 2/3 of the total) combined to the supplements (glycine 2, thiamine HC1 0.5, pyridoxin HC1 0.5, nicotinic acid 0.5, myoinositol 100 mg L^-1 and sucrose 3%) at concentrations of the "MS" medium or half of that were tested. Best rooting was obtained with NAA or IBA 1 mg L^-1, but in shoot tips having grooves, maximum rootings were with 0.25 to 0.5 mgL^-1 of IBA. Salt concentrations of 1/3 of the total allowed 100% rooting when added to the complete supplements.