Efficient Plant Regeneration using Mature and Immature Embryos of Maize (Zea mays L.)

Under this study an efficient protocol on callus induction (CI) and plant regeneration (PR) was developed using immature (IE) and mature embryos (ME) of four maize varieties viz. Barnali, Mohar, Khoi bhutta and Shuvra. For callus induction three basal media viz. MS, N6 and 6N1 were used where different concentration of 2,4-D (0.5, 1.0, 1.5, 2.0 mg/l) were used. Among the tested varieties, highest 75.28 and 77.16% callus were recorded for Mohar in MS supplemented with 1.5 mg/l BAP using immature and mature embryos respectively. The lowest value (25.48%) was recorded for Khoi bhutta on 6N1 + 0.5 2,4-D in ME. For PR, 3-4 weeks old calli were transferred to regeneration media (MS, N6 and 6N1) with BAP (0.5, 1.0, 1.5, 2.0 mg/l) and/or IAA (0.0, 0.5, 1.0, 1.5 mg/l). The maximum regeneration (77.44%) was found in MS that supplemented with 1.0 BAP and 0.5 IAA for Shuvra by IE and from ME, Mohar showed 76.09% regeneration. In the same medium combination, the highest elongated shoot (20.47cm) was recorded for Shuvra in IE; and from ME the value was 22.45 cm for Mohar. The variety Mohar also exhibited the maximum rooting (82.84%) in MS supplemented with 1.0 BAP and 0.5 IAA when it was regenerated from ME derived calli. Analysis of variance (ANOVA) showed significant differences among genotypes, media and hormonal combinations for callus induction and regeneration at P < 0.01.