Determination of hybrid vigor and inheritance for Regeneration in rapeseed (Brassica napus)

In rapeseed (Brassica napus L.) callus growth and regeneration are genotype-specific. In order to study the genetic control of these traits, nine pure lines of rapeseed (Brassica napus L.), Orakel, ACSN1, P504588, P704591, Boanty, Lisandra, Shirallee, Maluka and Global, which were previously selected for differences in callus characteristics in five MS media supplemented with different combination of hormones as control (without hormone), A (1 BAP , 0.5 2,4-D), B (2 BAP, 1 2,4-D), C (3 BAP, 1.5 2,4-D) and D (1 BAP, 2 2,4-D) and four type of explants as hypocotyl, cotyledon, seed and root were used. The experiment was factorial based on completely randomized design with four replications. Data were collected after five weeks on percent of callus induction, callus diameter, callus fresh weight and percentage of callus water content. Comparison of means in growth regulator media showed that in all traits, effect of genotype, media, and explants were significant (p=1%) except for percent of callus formation in different media. First and second order interaction were significant in all traits. On the whole medium, A was the best media and seed was the best explants in this medium. All 15 F1 hybrids and their parents with differences in callus characteristics (Orakel, ACSN1, P504588, P704591 and Boanty) were used for mature embryo culture after two different periods of callus maintenance and were evaluated for callus induction and plant regeneration capability in four replicates. We concluded that the gene(s) controlling regeneration are probably different from those controlling callus growths. The statistical analysis of the results revealed that positive heterosis was noticed for all these characters.