R. Ortiz et Dr. Vuylsteke, GENETICS OF APICAL DOMINANCE IN PLANTAIN (MUSA-SPP AAB GROUP) AND IMPROVEMENT OF SUCKERING BEHAVIOR, Journal of the American Society for Horticultural Science, 119(5), 1994, pp. 1050-1053
Apical dominance, i.e., the inhibition of lateral bud growth due to gr
owth substances released by the terminal bud, has been considered as a
limiting factor for the perennial productivity of plantains (Musa spp
., AAB group). Segregation ratios in F1 and F2 plantain-banana hybrids
suggest that inheritance of apical dominance is controlled by a major
recessive gene, ad. The dominant Ad allele improved the suckering of
plantain-banana hybrids, as measured by the height of the tallest suck
er at flowering and harvest. At harvest, the ratoon crop of the diploi
d and tetraploid hybrids had completed 70% to 100% of its vegetative d
evelopment, whereas the ratoon of the plantain parents, due to high ap
ical dominance, was only at 50% of total pseudostem growth. Sucker gro
wth rates are generally the result of gibberellic acid (GA3) levels, a
nd it is suggested that the Ad gene regulates GA3 production. However,
the Ad gene has incomplete penetrance, genetic specificity, and varia
ble expressivity. Increased frequency of the Ad gene and a commensurat
e improvement in the suckering behavior of the diploid populations may
be achieved by phenotypic recurrent selection.