Abstract:
Four treatment combinations with two levels of 2, 4-dichlorophenoxyacetic acid (2, 4-D) (0.2 and 0.5
mg/L) and two levels of indole acetic acid (1AA) (1 and 4 mg/L) with kinetin (0.1 mg/L), selected from
150 combinations of the above hormones tested initially for direct plant regeneration from leaf tissues,
were further tested in a completely randomized layout with 30 replicates. Leaf ex-plants of sugarcane
variety SL 96 328 were used for all cultures in modified MS medium added with cysteine hydrochloride,
40 mg/L. After 3 weeks, culture survival/ mortality and the number of plantlets directly regenerated from
ex-plants were recorded in one-week interval. Logistic regression was used to model the survival rates of
ex-plants of different hormone combinations. The culture medium with kinetin (0.1 mg/L), 2, 4-D (0.5
mg/L), IAA (1 mg/L) and cysteine hydrochloride (40 mg/L) showed the best plant regeneration directly
from leaf spindle disks after 4 weeks in culture. An average of 21 plantlets were obtained from an
immature leaf spindle disk of 2 mm thickness and 3 mm in diameter taken from 5- to 7- month old
sugarcane plants.
