Effectiveness of tissue culture media components on the growth and development of cauliflower (Brassica oleracea var. Botrytis) seedling explants in vitro

A key factor in the application of in vitro techniques to cauliflower improvement is the development of efficient protocols for regeneration of plants from tissue for use in breeding programs for the selection of the desirable genotypes under biotic and abiotic stress. Experiments were conducted to study the effect of different media components (agar or agar + sucrose or agar + Murashige and Skoog (MS) salts or agar + sucrose + MS) on callus induction and regeneration from five explants types (cotyledon, hypocotyls, shoot apex, primary root and root tip) and also the effects of auxin and cytokinin were carried out using one F1 hybrid cauliflower cv. Medallion. The results show that cotyledons, mid roots and root apices grown on agar + MS + sugar were the most developed compared with explants on the other media. This medium was the most productive in terms of lateral root number and root length. The presence of 2,4-dichlorophenoxyacetic acid increased callus production compared to 6-benzylamino purine. Within the selected explants, a significant difference was indicated between different explants under different treatments. Liquid culture was more successful at producing viable plantlets than solid culture.Key words: Cauliflower, explants, in vitro, growth regulator, growth characters, solid and liquid culture

An Investigation of Gene Action on Different Traits of Barley (Hordeum Vulgare L.) Using Partial Diallel Crosses System

Abstract: The present study was carried out to investigate the genetic structure of 10 hybrids generated by crossing five cultivars of barley with their first (F 1 ) and Second (F 2 ) progeny in growing season 2011-2012 to evaluate these genotypes under normal (0.0 g l -1 sea salt) and salinity stress (7 g l -1 sea salt) conditions in form of randomized complete block design with three replications in a half diallel fashion. The studied traits included spike length (cm), no. of kernels/spike, no. of spikelets/spike, no. of spikes/plants, chlorophyll a, b contents, calcium and magnesium content. The analysis of variance revealed significant differences among genotypes (5 parents + 10 F 1 's+ 10 F 2 's) and for all the studied traits, except chlorophyll b. The results showed that components additive and dominance effects of genes were significant for all studied traits. The estimated value of average degree of dominance (H 1 /D) 0.5 revealed that non-additive genetic effects was more pronounced in the inheritance of the chlorophyll a, b contents, calcium and magnesium in all the two generations (F 1 and F 2 crosses) and spike length (cm), no. of kernels/spike, no. of spikelets/spike and no. of spikes/plants for F 1 crosses. . On contrary, additive genetic effects was evident for spike length (cm), no. of kernels/spike, no. of spikelets/spike and no. of spikes/plants for F 2 crosses. The traits including, chlorophyll a, b and calcium were controlled by over dominance in all the two generations (F 1 and F 2 crosses). The traits including spike length (cm), no. of kernels/spike, no. of spikelets/spike and no. of spikes/plants controlled by over dominance in F 1 crosses and partial dominance in F 2 .While, magnesium were controlled by partial dominance effects of genes. The genetic component (H 2 ) was recorded with low magnitude than (H 1 ) for all traits in both F 1 and F 2 under 0.0 and 7 gl -1 sea salt. The f value was positive for most traits of F 1 and F 2 generations, while it was negative for magnesium in both of F 1 and F 2 generations in all cases of sea salt treatments. The narrow sense heritability was high to moderate for most the studied traits. Moreover, the lowest value was also detected in some cases