In vitro propagation of thermosensitive genic male sterile rice (Oryza sativa L.)

Abstract

The project entitled “In vitro propagation of thermosensitive genic male rice (Oryza sativa L.)” was conducted in the Department of Plant Physiology, College of Agriculture, Vellayani during 2015-2016. The main objective of the study was to standardize the method for in vitro propagation of thermosensitive genic male sterile rice. The plant material used for this study were the TGMS line (EC720903) imported from IRRI, Philippines as female parent and two red varieties viz. Uma and Jyothi were selected as pollen donors. F1 progenies were generated from the cross between TGMS line (EC720903) with Uma and Jyothi through proximal hybridization technique. The obtained F1 population have subjected to self-pollination to produce F2 population. The screened sterile plants were used as source material for in vitro multiplication. In this present study, three explants (anthers, leaves and node) from TGMS rice were used for in vitro multiplication. Sterile anthers and leaf explants were inoculated on callus induction media (N6, B5 and MS) supplemented with different combination of auxins (2, 4-D, NAA, IBA) and nodal segments were inoculated in to shoot induction media (MS) with different concentration of growth regulators. In vitro regeneration protocol of TGMS rice was optimized from nodal segments through various steps of shoot regeneration, in vitro rooting and acclimatization and planting out.Shoot regeneration from nodal segments with maximum shoot induction was obtained in the medium MS supplemented with BA (2 mg L-1)+ NAA (0.5 mg L-1). Highest root induction was obtained in MS with NAA (1 mg L-1). The ex vitro establishment of in vitro regenerated plantlets showed maximum survival rate in coirpith: vermicompost (1:1) media. No callus regeneration was observed from any of the treatment tried in sterile anthers and mature leaves.