In Vitro Selection of a Drought Tolerant Callus of Dwarf Napier Grass (Pennisetum purpureum Cv. Mott)

Drought stress causes 50% yield losses of plant production in a tropical area like Indonesia. In vitro selection was a method to the identified somaclonal variation of dwarf Napier grass by using callus induction. The non-ionic water-soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress for in vitro selection. This study aimed to use somaclonal variation to select drought-tolerant plants of dwarf Napier Grass. Multiple shoot clump (MSC) of sterilized explant were cultured on Murashige and Skoog (MS) medium containing 2 mgL-1 2,4-dichlorophenoxyacetic acids (2,4-D), 50 ml/l coconut milk (callus growth medium; CGM) with 30 g/l sucrose and 3 g/l phytagel for callus induction. The calli were grown on CGM with five concentration of PEG for selected medium (0, 40 mu M, 80 mu M, 120 mu M and 160 mu M) for 6 weeks. There were significant differences between fresh and dry weights of callus in different concentrations of PEG. Callus regeneration of dwarf Napier Grass occurred at the concentration of 40, 80, 120 and 160 mu Mof PEG and all regenerated MSC well rooted on all concentration PEG. In order, regenerated shoot occurred at the concentration more than 80 mu M PEG solutions.