EFFECT OF COLD PRETREATMENT AND PHYTOHORMONES ON ANTHER CULTURE EFFICIENCY OF TWO INDICA RICE (Oryza sativa L.) HYBRIDS-AJAY AND RAJALAXMI

Application of anther culture techniques for improvement of indica rices is a formidable task as they are known to be recalcitrant to culture unlike japonica rices. Since anther culture can effectively address the major problems associated with the adoption of hybrid rice in India, an effort was made to assess the influence of cold pretreatment and phyto hormones on the anther culture response of Rajalaxmi (CRHR 5) and Ajay (CRHR 7), two elite and popular indica rice hybrids. Cold pretreatment for 7-9 days at 10 degrees C was found to have a positive influence on the callus induction frequency irrespective of the media employed and prolonged treatment over the optimum proved to be inhibitory. Of the different auxins (2, 4-D, NAA) and cytokinins (Kinetin, BAP) and their combinations studied, a ratio of 1:4 for 2,4-D and NAA and 1:3:1 ratio of Kinetin: BAP: NAA ratio proved to be optimal for callus induction and green plant regeneration respectively. This information can be of use in the development of doubled haploids with superior yield and good grain quality from the elite hybrid cultivars.