Establishment of a highly efficient and reliable protocol for seed germination and callus formation from cultured rice seeds

In the present investigation, dehusked rice seeds were tissue cultured on seven MS basal media with the supplementation of divergent concentrations and conjunction of kinetin and 2,4-dichlorophenoxy acetic acid to avail in vitro seed germination and callus formation. It was noticed that medium M1 (MS + 2.50 mg/L 2, 4-D) revealed the higher formation of callus but the lowest seed germination in rice varieties. Among auxins, 2,4-Dichlorophenoxy acetic acid is detected to be the utmost potent auxin for in vitro callus formation in rice. Moreover, the higher concentration of 2,4-dichlorophenoxy acetic acid in the remaining six media, namely, M2, M3, M4, M5, M6, and M7 enhanced the formation of callus and decreased germination of rice seed. Additionally, the highest kinetin concentration enhanced the germination of seed and decreased the formation of callus in rice. Thus, the formation of the callus can accelerate the rice improvement through somaclonal variation. Furthermore, in vitro-formed calluess, shoot buds, and roots can be employed as rudimentary explants for successful genetic transformation. Therefore, a highly efficient and reliable protocol was established for in vitro germination of seeds and the formation of callus from cultured rice seeds. This protocol will be very reproducible for acquiring in vitro germination of seed and formation of callus based on varied biotic and abiotic stress tolerance mechanisms in rice.