ISHS Acta Horticulturae 336: II International Symposium on In Vitro Culture and Horticultural Breeding
DISEASE RESISTANCE, CELL CULTURE AND SOMATIC RECOMBINATION |
| Authors: | P.J. Larkin, Y. Li, L.H. Spindler, G.J. Tanner, P.M. Banks |
| Keywords: | Triticum aestivum, Agropyron, BYDV, luteovirus, somatic hybridization, introgression |
| Abstract:
Barriers to meiotic recombination are major constraints on plant improvement using exotic germplasm. Wide hybrids are of little value without a means to ensure recombination between the disparate genomes. Cell culture induces chromosome breakage and fusion resulting in non-homologous translocations. It is argued that culture can be employed as a means to obtain somatic recombination and subsequently plants with translocations between the exotic and cultivated chrosomes. Two examples are given, one involving sexually obtained alien chromosome addition lines, the other involving asymmetric somatic hybrids. Barley yellow dwarf virus resistance was located on a Thinopyrum intermedium chromosome. Following cell culture of the appropriate addition line to wheat, plants were obtained with the resistance gene apparently translocated to a wheat chromosome. Fusion between iodoacetamide-treated protoplasts of lucerne (Medicago sativa) and gamma-irradiated protoplasts of sainfoin (Onobrychis viciifolia) resulted in the recovery of highly asymmetric somatic hybrids that are morphologically similar to lucerne. Southern hybridization with total genomic probes has established the presence of small fragments of sainfoin chromatin in these plants. | |
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