Effect of Genotype and 2,4- D Concentration on Callus Induction from Immature Embryos of Modern Egyptian Wheat Cultivars

Abstract

Thirteen Egyptian bread wheat (Triticum aestivum L.) cultivars and Bobwhite were evaluated for their potential use in tissue culture studies using three different concentrations of 2,4-dicholorophenoxyacetic acid (2,4-D). Modified medium of Cheng et al (1997) supplemented with 0.5 mg/l, 1.0 mg/l, and 2.0 mg/l of 2,4-D were used. The results showed genotypes, 2,4-D concentrations and their interactions significantly affected the percentage of embryogenic calli induced, regenerable calli and regenerated green plants. The highest responding genotypes across the three concentrations of 2,4-D were Gemmieza 3 (69.6%) for embryogenic calli, Sakha 69 (88.2%) for regenerable calli and Gemmieza 3 (92.3%) for regenerated green plants. The most favorable concentration of 2,4-D, across all genotypes, was 0.5 mg/l with high frequencies of embryogenic calli (48.6%), regenerable calli (77.3%) and regenerated green plants (76.7%). Highly significant genotype by 2,4-D concentrations interactions were observed for all studied traits. The best responding genotypes at the lowest concentration of 2,4-D (0.5 mg/l) were Gemmeiza 3 (80.7%) for embryogenic calli, Giza 167 (90.1%) for regenerable calli and Gemmieza 3 (95.3%) for regenerated green plants. At the higher 2,4-D concentrations, Sakha 69 was the best cultivar for embryogenic calli (68.7%; 2.0 mg/l 2,4-D), regenerable calli (94.2%; 2.0 mg/l 2,4-D) and regenerated green plants (94.8%; 1.0 mg/l 2,4-D). The response of Gemmeiza 3, Giza 167 and Sakha 69 was better or equal to Bobwhite at different 2,4-D concentrations.