A hybrid index for Allium cepa x A. fistulosum crosses

A hybrid index for Allium cepa x A. fistulosum crosses

Wellesbourne, Warwick Institute of Horticultural Research United Kingdom

1988

p.190-196

SB339.A4I5

A hybrid index was devised, based on 8 characters which distinguish the two parent species, Allium cepa and A. fistulosum. The characters were: leaf cross-section; bulbing; dormancy; general flower appearance; "flower angle" (the maximum angle formed by the tepals); "flower length" (maximum length from base of perianth to tip of stigma); length of longest tepal; and general inflorescence appearance. Three of the characters were quantitative and the others qualitative. The results were expressed diagrammatically. Interspecific F1 hybrids formed a discrete intermediate group and the first backcrossed generation (BCls) to A. cepa a more widely spread group with a tendency to resemble A. cepa: BC2s to A. cepa were virtually indistinguishable from A. cepa on the basis of morphology. Flower length at maturity and flower angle appeared to be the most useful characters for distinguishing BC1s, as these characters were stable, distinct and could easily be measured. Tetraploid and triploid plants had tepals which were relatively wide than those of diploid intermediates, and could be distinguished by their increased tepal width: length ratio. Percentage of stainable pollen in F1s, BC1s and BC2s in successive seasons is shown and the techniques which tended to raise seed productivity in the intermediates are noted. [AS]

Allium symposium: EUCARPIA - section vegetables; Proceedings

Research > Published Articles