Large-scale production, field performance and RAPD analysis of micropropagated sugarcane plants

Abstract

An improved procedure has been developed for the micropropagation of true-to-type plants of two early maturing varieties of sugarcane, CoH92 and CoH99. The protocol Involved (i) growth and proliferation of shoot tip explants in MS medium containing gibberellic acid, indole-3-acetic acid and kinetin, (ii) 3-6 rounds of shoot multiplication in MS medium enriched with 6benzylaminopurine and kinetin, (iii) rooting In MS medium with (a-naphthalene acetic acid and sugar at higher concentrations, and (vi) hardening of plantlets and their transplantation into 1:1 mixture of unsterilized sand and soil under natural conditions. Shoot multiplication and rooting media contained food grade cane sugar and Isubgol™ as cheaper substitutes in place of sucrose (pure grade) and agar, respectively. This procedure does not require expensive equipment and facilities such as water purification units, greenhouse, polyhouse, etc. Plants propagated through micropropagation and conventional means using setts compared well for various agronomic (cane length, cane weight, number of internodes per cane, internode length) as well as sugar yield/quality traits (purity and CCS). Micropropagated plants had relatively higher number of millable canes, but they were thinner than the conventionally propagated cane. Plants propagated through setts of the micropropagated plants were genetically stable for all the traits. RAPD marker analysis using 20 primers clearly established the clonal fidelity in >90% of micropropagated plants.