Callus induction and plant regeneration from mature embryos of a diverse set of wheat genotypes

This paper compared the behavior of a diverse set of wheat genotypes in their tissue culture response. Significant differences were detected in plant regeneration, culture efficiency, and regeneration capacity when mature embryos of 47 wheat cultivars, breeding lines, and the common wheat progenitors, Triticum monococcum, T. tauschii, and Aegilops speltoides were compared. Although not currently used in wheat tissue culture, mature embryo-derived callus of cv. 'Zak' (SWS), 'Scarlet' (HRS), Tara' (SWS), 'Jagger' (HRW), 'UC 1036' (HRS), and 'Kyle' durum showed better or comparable plant regeneration than commonly cultured cultivars 'Fielder' and 'Bobwhite.' Of the three diploid wheat progenitors tested, Ae. speltoides regenerated the most plants. In one replicated experiment, callus induction was correlated with culture efficiency (r = 0.42; p = 0.002) and regeneration capacity (r = 0.39; p = 0.002), and in a second larger screen, callus induction correlated with the total number of plants regenerated (r = 0.6; p = 0.001). Immature and mature embryos of 'Bobwhite' and 'Crocus' were compared for callus induction and plant regeneration. Immature embryos were superior explants in terms of plant regeneration. However, sufficient numbers of plants can be regenerated from mature embryos saving on growth facility resources and time required for the collection of immature embryos.