Improved rate of callus induction from rice anther culture following microscopic staging of microspores in iron alum-haematoxylin.

High frequencies of callusing were obtained in indica rice from the microspores which were staged in acetic acid iron alum-haematoxylin stain prior to culture on G5 medium. Two local varieties, 'Khonorullo' and 'Namyi', and two advance pre-release cultures, 'PK 1-1-3' and 'PK 12-22', were used in this investigation. All the cultures exhibited a wide adaptation to varying medium; however, the frequency of callusing was highest (45.5%) in 'PK 1-1-3' followed by 'PK 12-22' (32.4%) and 'Khonorullo' (31.6%). Cold shock (10 °C) for 11 days enhanced the frequency of callusing by 200% in 'Khonorullo'.