EFFECT OF GENOTYPE, MEDIA AND EXPLANTS ON MICROPROPAGATEON OF SUGARCANE

Abstract

in Bangladesh, yield of sugarcane is very low due to environmental factors including disease and insect pest infestation. Farmers need to wait for sct sowing due to flood. Delayed sowing hamper the formation of sugar during maturation of sugarcane finally resulting in yield loss. Moreover, time requirement and continued infection by systemic disease are serous problems to multiply of sugarcane in the open field. The present study was conducted to select a suitable explant and protocol of micropropagation of BSRI released three sugarcane varieties. Bud, shoot tip and leaf sheath of the most important sugarcane varieties viz. Isd 16, IsdM and 1sd37 were used as explants. Bud and shoot tip explants were used for direct shoot initiation and leaf sheath explants were used for callus formation followed by shoot initiation. Different concentrations of cytokinin (BAP or 1(n) alone and different combinations of cytokinin (RAP) with auxin (NAA or IBA) were used with MS medium to observe their effects on shoot initiation. BAI' showed better performance than Kn for shoot initiation. Effectiveness of the combination of cytokinin (RAP) with auxins (NAA or IRA) was proved to be superior to that of concentrations of cytokinin (BAP) alone. Best results were obtained from all the three varieties in MS medium supplemented with 2.0 mg/I RAP + 0.2 mg/I NAA for shoot initiation from the bud and shoot tip explants. Diflèrent concentrations of auxin (NAA and 2.4-13) were used with MS medium to observe their effects on callus formation. Best restilts were observed from the varieties lsd36 and 1s07 at 4.0 mg/I of 2.4-D and the variety lsdl6 at 3.0 mg/I of 2,4-D for callus inducoon. Different combinations of RAP with NAA or IRA with MS medium were used for shoot initiation and multiplication from callus. 1.0 mg/I RAP - 0.5 mg/I NAA showed the best result for multiplication of shoots for all varieties. MS medium supplemented with different concentrations of auxin (NAA and WA) were used alone for in vitro root formation from proliferated shoots. NAA showed better perforniance than IRA for root initiation. Best result of root formation was observed on MS medium supplemented with 5.0 mg/I of NAA. The variety 1sd37 produced the highest number of roots (13.47) at 5.0 mg/I of NAA. Interactions of varieties and media exerted remarkable effects on shoot and root lbrmation capabilities. The plantlets were successfully transferred to soil with eighty to ninety percent survivability at normal temperature with 85% humidity.