Fig. 3

A backcross analysis of callus colour profile. Callus colour was grouped into five classes in ascending order of yellow in the callus: bbbb, bbbY, bbYY, bYYY and YYYY. B. neohumeralis parentals were almost always ‘bbbb’ while B. tryoni parentals were ‘YYYY’. Row F1shows the callus colour distribution in F1 hybrids, while row B1shows the callus colour distribution in the F1 x B. neohumeralis backcross partitioned by the sex and species of parental mated to the B1 individual. The average proportions were calculated partitioning by sex with the standard deviation of the proportion across the three replicate lines included on each bar