Abstract

Nodal segments (1.5 - 3.0 cm long) of six promising jojoba genotypes were culturedin vitro on solidified MS medium supplemented with BA in combination with different concentrations of NAA, IAA or IBA for shoot formation. The plant growth regulators combination of 5.55 µM BA + 7.1 µM IAA proved the best for shoot initiation and subsequent growth. Some explants of the jojoba genotypes, PKJ-3 and PKJ-6, developed thick rootlets when BA (5.55 µM) was used in combination with IBA (6.1 µM) or NAA (6.7 µM). Many explants developed callus on the medium containing BA (11.1 µM) in combination with NAA (13.4 µM), IAA (14.3 µM) or IBA (12.2 µM). In vitroderived shoots were rooted by culturing on solidified MS medium containing IBA (6.1 µM), IAA (7.1 µM) or NAA (6.7 µM). The plantlets which developed roots in response to IBA had the maximum survival percentage (63.33) during acclimatization in greenhouse. However, survival of the plantlets in field conditions was independent of the genotypes and the time of planting. Among the genotypes, PKJ-3 performed the best in all the parameters studied.

Key words: Auxins, cytokinins, genotypes, jojoba, micropropagation, Simmondsia chinensis.

Abbreviation

BA, N⁶-Benzyladenine; IAA, indole-3-acetic acid; IBA, indole-3-butyric acid; NAA, a-napthalene acetic acid; PGRs, plant growth regulators.