Alfalfa (Medicago sativa) somatic embryogenesis:: genetic control and introduction of favourable alleles into elite Argentinean germplasm

The objectives of this work were to isolate regenerative genotypes from the alfalfa Canadian cultivar 'Rambler' to perform the genetic analysis of somatic embryogenesis in this species and to introgress regeneration favourable alleles into Argentinean alfalfa elite germplasm. For regeneration inheritance studies, greenhouse established plants from a cross between a 'Rambler' derived regenerative clone and a non-regenerative Argentinean clone as well as self-pollinated progenies of these clones were analyzed. The results showed that somatic embryogenesis is under the control of two complementary genes. The introgression of somatic embryogenesis favourable alleles was performed using two populations derived from crosses between regenerative clones, obtained in the first step of this work, and non-regenerative clones of Argentinean alfalfa elite populations. Twenty-seven plants obtained through this process showed somatic embryogenesis ability. Two of them, designated as INTA R1 and INTA R2, exhibited a high regeneration capacity as well as high regeneration multiplicity. Our results demonstrate that 'Rambler' derived somatic embryogenesis favourable alleles are successfully expressed in Argentinean elite alfalfa genetic background rendering it suitable for tissue culture-based breeding methodologies.