The restricted branching character appears to be unstable in some genotypes
of narrow-leafed lupin (Lupinus angustifolius L.). This study investigated
random cross-pollination as a possible cause. Restricted and normal branch
ing genotypes with different flower colours were grown in field plots, the
progeny seed was sown, and the frequencies of off-flower colours, indicatin
g cross-pollination, were recorded. Six pairs of genotypes were studied and
there was no detectable cross-pollination in 3 pairs, <0.1% in 1 pair, and
about 2% in the other 2 pairs. Cross-pollination appears to be related to
genotype and there was no relationship with position of the mother plant in
the plot, flower position on the mother plant, or architecture (branching
habit). Most cross-pollination was on blue-flowering mother plants.