INTROGRESSION OF ALLIUM FISTULOSUM L. INTO INTERSPECIFIC HYBRID BACKCROSSES BETWEEN A. FISTULOSUM L. AND A. CEPA L.
Allium fistulosum L. shows resistance to many diseases and pests of bulb onion, among them, pink root. The introgression of resistant genes from A. fistulosum into A. cepa has been the objective of plant breeders for decades. F1BC1 populations were generated for this study by backcrossing A. cepa to A. fistulosum x A. cepa hybrids. The F1 hybrid and 538 F1BC1 plants from 4 populations were evaluated at plant maturity for the incidence of pink root disease, number of leaves, and bulb diameter. The F1 exhibited a pink root index similar to the resistant parent and the morphology was intermediate between the two progenitors, providing evidence that the cross took place. In general, the F1BC1 plants were much alike A. cepa, in relation to the susceptibility to pink root and morphology, while some of them showed A. fistulosum resistance with A. cepa bulbing ability. Although the F1 plants showed low fertility, recombination between A. cepa and A. fistulosum was achieved. At present the backcross program is being pursued in order to obtain onion plants resistant to pink root.
Martínez, L.E., Galmarini, C.R. and Masuelli, R.W. (2005). INTROGRESSION OF ALLIUM FISTULOSUM L. INTO INTERSPECIFIC HYBRID BACKCROSSES BETWEEN A. FISTULOSUM L. AND A. CEPA L.. Acta Hortic. 688, 109-116
bulb onion, bunching onion, pink root, Phoma terrestris