NATURE OF GENE ACTION FOR IMMATURE EMBRYO CULTURE ABILITY IN WHEAT (Triticum aestivum L(

Abstract

The objective of this study was to determine the genetic parameters involved in immature embryo culture ability in wheat (Triticum aestivum L). For this purpose, five lines and two cultivated varieties were used. These lines were: C.B243, C.B245, C.B249, C.B251 and C.B253. While, the two testers were Gemmieza 9 and Gemmieza 10. The results showed the presence of highly significant differences among genotypes for all in vitro traits. This indicated that embryogenic calli induction and its regeneration were affected by the genotypes of the immature embryo donor plants. The line C.B 251 was the most responsive for both embryogenic calli ratio and regenerable calli ratio, while the line C.B243 was the best combiner among other lines in the case of callus fresh weight. The beast combination for all traits was the cross C.B 251× Gemmieza 9. Furthermore, the results revealed that both additive and nonadditive genetic variances played an important role in the inheritance of immature embryo culture traits. However, the magnitude of non-additive genetic variance was larger than their corresponding estimates of additive genetic variances for callus fresh weight and regenerable calli ratio. This finding was emphasized by the dominance degree value which exceeded unity with respect to these traits. Therefore, it could be concluded that using F1 hybrids for immature embryo culture improvement the ability to induce high ratio of plantlets.