Effect of Explant Sources and Different Concentrations of Plant Growth REGULATORS ON IN VITRO SHOOT PROLIFERATION AND ROOTING OF AVOCADO (PERSEA AMERICANA MILL.) CV. "FUERTE"

Abstract

In vitro shoot proliferation and rooting capacity of avocado cv. Fuerte was tested by using two different types of explant sources i.e., apical and axillary buds with varying concentrations of BAP and IBA on MS media. Explants exhibited a different response towards shoot proliferation with highest shoot number by axillary buds (2.50). By contrast, the apical buds yielded fairly positive results for shoots length (2.16 cm) than axillary buds. A good response was observed in axillary buds with 1.0 mg l BAP (T3) which lead to the best rate of shoot multiplication (4.80), whereas 1.5 mg l BAP (T4) favored the good shoot length development (4.06 cm) with apical buds. Among various BAP treatments, both T3 (1.0 mg l) and T4 (1.5 mg l) had a promotory effect on mean shoot number (3.23) and shoot length (2.91 cm). Rooting study revealed that explants also showed a variation in their rooting potential as apical buds proved to be superior with maximum 29.19% rooting, 2.15 roots per explant and 2.11 cm root length however, axillary buds did not have a significant affect on these parameters. Apical buds in interaction with 1.0 (T3) and 1.5 mg l IBA (T4) gained a higher rate of 53% rooting and 3.2 roots per explant while at 0.5 mg l IBA (T2) they resulted in an outcome of 3.58 cm root length. Within IBA treatments; T2 (0.5 mg l), T3 (1.0 mg l) and T4 (1.5 mg l) gave 3.4 cm root length, 40% rooting and 2.81 mean root number, respectively.