Micropropagation of elite genotype of Jatropha curcas L. through enhanced axillary bud proliferation and ex vitro rooting

摘要

We developed simple, improved and reproducible micropropagation process for elite and mature genotype of jatropha curcas L. through enhanced axillary bud proliferation. On 7 g L~(-1) agar-gelled Mura-shige and Skoog's (MS) medium containing 2.0 mg L~(-1) 6-benzylaminopurine (BAP) and 0.1 mg L~(-1) indole-3-acetic acid (IAA), 96.67 ± 3.33% explants produced 1.73 ± 0.07 shoot buds of 1.27 ± 0.04 cm per explant. Shoots were multiplied (9.33 ± 0.09 shoot buds of 2.18 ± 0.01 cm per nodal segment) by sub-culturing the in vitro-derived nodal segments on MS medium containing 0.5 mg L~(-1) each BAP and IAA. On half-strength of MS salt with 2 g L~(-1) activated charcoal (AC) and 3.0 mg L~(-1) indole-3-butyric acid (IBA), 73.33 ± 3.33% of the shoots rooted in vitro. Alternatively the bases of microshoots were treated with 500 mg L~(-1) IBA for 3 min and transferred onto sterile mixture of soilrite and soil (1:1 v/v). 70.00 ± 5.77% of shoots rooted ex vitro, which could be acclimatized simultaneously. The rooted plantlets were acclimatized by slow and gradual exposure from high (75-85%) relative humidity (RH) and low (24 -26 ℃) temperature to low (40-50%) RH and high (30-32 ℃) temperature. The cloning procedure described is superior to methods reported earlier and has potential applications for large-scale true-to-type propagation of J. curcas to supply planting propagules for promotion of commercial plantation.