In vitro ropagation of two garlic (Allium sativum L.) Cultivars through bulblet formation

Abstract

In vitro propagation is considered as an alternative tool for garlic seed bulb propagation as vegetative method is not effective to produce sufficient quantity. Experiments were carried out to optimize a protocol for In vitro propagation of two local garlic (Allium sativum L.) cultivars (Bishoftu and Tseday) through bulblet formation from meristem-tip derived explants. From the two cultivars, meristem-tips that measure 1mm were excised and cultured on plant growth regulators free MS medium for shoot initiation and 82.5% of them were regenerated and form tiny shoots. Then, the initiated shoots were transferred to shoot proliferation medium supplemented with NAA and BA. The optimum concentration and combination of hormones for the two cultivars showed statistically significant differences in shoot induction parameters. Cultivar Bishoftu gave better average shoot number (6) and shoot length(5.78cm) on MS medium supplemented with 2mglP -1P BA and 0.5mglP -1PNAA where as cultivar Tseday gave better average shoot number (5) and average shoot length ( 7.57cm) on 2 mglP -1P of BA and 1mglP -1P of NAA. The best growth of bulblet interms of diameter (0.62cm), fresh weight (0.36g) and dry weight (0.20g) in Bishoftu and diameter of 0.64cm, fresh weight of 0.40g and dry weight of 0.31g in Tseday were achieved on MS media fortified with 11% sucrose and 0.2mglP -1P of NAA followed by 2mglP -1P of BA. Well-developed bulblets were rooted on ½ strength MS basal medium supplemented with different concentration and combination of NAA and BA. The best average root number and average root length (6 and 3.17cm in Bishoftu and 5 and 3.02cm in Tseday) were obtained at 1.5 mglP -1P of NAA and 0.5 mglP - P 1of BA respectively. The rooted bulblets were transplanted to pots that contain a mixture of forest soil, sand and compost in 1:1:1 ratio. 85% of Tseday and 81% of Bishoftu bulblets were successfully established and survived. This study established an effective protocol for In vitro propagation of garlic of the two cultivars through bulblet formation from meristem-tip culture Additional studies such as production of disease free seed bulbs of garlic cultivars and viral indexing as well as cryopreservation will be fruitful to conduct.