STUDY ON THE PRODUCTION AND DORMANCY BREAKING OF POTATO MICROTUBER

Abstract

Experiments for the production and breaking of dormancy of niicrotubers of a potato cultivar "Diamant" have been conducted at the tissue culture laboratory of HRC. BAR!, during January to June semester. 2008. Five levels of CCC (0,100, 300, 500 and 700 mg/I) and six levels of sucrose (0, 3, 6, 9, 12 and 1 5%) were used in two separate experiments for the production of microtuber. Microtubers from both the experiments were harvested at three different dates (75, 90 and 105 days after addition of tuberisation media). For breaking of dormancy, GA 3 solution (0, 0.1, 0.5 and 1.0 mg/I) was used to soak peeled microtuber for I and 5 minutes followed by suberisation at 85% RH and 15-18° C for 48 hrs. CCC @300 mg/I produced microtuber earliest by 7.11 days in order to produced the maximum number (6.56) and weight of microtubers per flask (870.85 mg), and mean tuber weight by 500 mg/I CCC (137.24 mg). By the application of CCC the percentages of tuber of<100 mg, 100-200 mg and >200 mg sizes were in the ranges of 13.29-48.70%, 37.40-50.07% and 10.18-37.76 0 ,/o, respectively. A culture period of 105 days produced the maximum weight/flask (808.67 mg) and mean weight of microtuber (121.47 rug) compared to 75 days (556.81 mg and 105.13 mg respectively). Sucrose @ 9% and 12% gave the highest tuber weight/flask (782.12 mg and 683.34 mg) and mean weight (137.94 mg and 133.73 mg). No tuber was formed at 0% sucrose level. Sucrose levels of 9-15% produced the minimum and the maximum percentages of< 100 mg (16.67-21.48) and >200 mg (32.22-34.81) size microtuber in number. GA3 @ 0. I mg/I, 5 min soaking time and suberiscd condition of tuber had the maximum 97.50% sprouted tuber within 7 days. CCC @ 300mgfl and 500 mg/I and sucrose level 9-15% for production and GA3 0.1 mg/I for breaking dormancy showed the best result.