Screening of Korean Rice Cultivars for their Shoot Regeneration Ability in vitro and the Effect of Maltose on Shoot Regeneration

Abstract

Regeneration ability of plant is very important for producing transgenic plants by genetic engineering. Fifty rice cultivars and lines were screened for their regeneration ability in vitro and an attempt was made to increase shoot regeneration by substituting sucrose with maltose in combination with two different concentrations of kinetin, 2 mgL1 and 10 mgL1 in regeneration media. As expected, it was confirmed that there was genotypic variation in shoot regeneration ability and the shoot regeneration rates of 50 cultivars and lines on MSRK2S ranged from zero to 87.2%. Sixteen out of 50 cultivars and lines showed over 50% of shoot regeneration rate while no shoot regeneration was observed from 10 cultivars on MSRK2S. Although high kinetin concentration in regeneration media increased callus browning and reduced green shoot formation, average shoot regeneration rate was not changed significantly. The substitution of sucrose with maltose in regeneration medium could increase the average shoot regeneration rate by over 9% via increasing the green tissue formation while decreasing callus browning significantly. By maltose substitution, 42 out of 50 cultivars and lines showed increased shoot regeneration rate. It was able to get shoot regeneration from six cultivars out of eight cultivars, that didn’t regenerate on MSRK2S and dramatic increase of shoot regeneration in two cultivars such as Areumbyeo and Suwon 477 was observed by maltose substitution. The result presented here could be a helpful guideline in selecting cultivars or lines for transformation and for developing better regeneration system for rice.