Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/23/2004
Publication Date: 8/1/2004
Citation: Satyavathi, V.V., Jauhar, P.P., Elias, E., Rao, M.B. Effect of growth regulators on in vitro plant regeneration in durum wheat. Crop Science. Vol. 44:1839-1846. Interpretive Summary: Although durum wheat is an important cereal crop used for human consumption worldwide, work on its improvement using modern biotechnology is limited. Standardizing a reliable protocol for regenerating full plants from callus tissue is a prerequisite for application of transgenic technology for improvement of current commercial cultivars. Therefore, we studied the effect of three important growth regulators (2,4-D, picloram and dicamba) on callus induction and plantlet regeneration in four commercial durum cultivars: Ben, Maier, Munich, and Lebsock. There were differences in regenerability among the four cultivars. We found that Maier had the highest percentage of plants regenerated when dicamba at 2.0 mg per liter is used in the culture media. Having standardized this regeneration protocol, we are now working on genetic transformation of Maier by incorporating antifungal genes for engineering scab resistance.
Technical Abstract: Work on improvement of durum wheat (Triticum turgidum L.) using tools of biotechnology is limited. Development of a reliable in vitro plant regeneration procedure of this important cereal is a prerequisite for its improvement by techniques involving direct gene transfer. Here, we report the effects of three growth regulators, 2,4-D (2,4-dichlorophenoxyacteic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), and dicamba (3,6-dichloro-o-anisic acid), on callus induction and plant regeneration from scutellum cultures of four commercial durum cultivars: Ben, Maier, Munich, and Lebsock. Callus induction was obtained from isolated scutella cultured on modified Murashige and Skoog basal medium. After four weeks of callus induction, all calli were plated on MS basal medium for regeneration. All regenerated plantlets were fertile, maintained the normal chromosome number (2n = 4x = 28) and structure as revealed by fluorescent genomic in situ hybridization, and showed no apparent somaclonal variation. Genotype and callus induction medium played a dominant role in plantlet regeneration. Overall, Maier gave the highest proportion (0.27) of plantlet regeneration. Dicamba proved the best for inducing compact callus and also gave the highest proportion (0.16) of regenerated plants across the four cultivars. These results will facilitate genetic transformation work with durum wheat.