NEAR-OPTIMAL LEVELS OF 2,4-DICHLOROPHENOXYACETIC ACID AND INDOLE ACETIC ACID FOR IN-VITRO DIRECT REGENERATION OF SHOOTS FROM SUGAR CANE (Saccharum spp. Hybrid) LEAF TISSU

Abstract

Four combinations with two levels of each 2,4-Dichlorophenoxyacetic Acid (2,4-D) (0.2mg/L, 0.5mg/L) and Indole Acetic Acid (IAA) (1mg/L, 4mg/L) together with 0.1 mg/L of Kinetin and 40mg/L of Cysteine Hydrochloride de termined by testing their 150 combinations for in-vitro direct shoot regeneration from sugarcane (Saccharum spp. Hybrid) leaf tissues were further evaluated using the variety SL 96 328 in a completely randomised layout with 30 replicates to find out their near-optimal levels. Leaf spindle slices of the sugarcane variety SL 96 328 was used as ex-plants for culture in the modified MS medium. After 3 weeks of culture, the survival of ex-plants and the num ber of shoots directly regenerated from ex-plants were recorded in one-week intervals. The concentration of 0.5mg/L of 2,4-D and 1mg/L of IAA together with 0.1mg/L of Kinetin and 40mg/L of Cysteine Hydrochloride re generated the highest number of viable shoots from leaf spindle discs after 4 weeks of culture. On average, 21 shoots were obtained from a leaf spindle disc of 2mm thickness and 3mm in diameter obtained from sugarcane plants of 5- to7- month old.