Extended Data Fig. 1. Hybrid crosses between P. exspectatus and P. pacificus.

Sex ratio of progeny of hybrid crosses of P. exspectatus and P. pacificus (a) and backcrosses of F1 hybrids produced by crosses between P. exspectatus females and P. pacificus males (b) and backcrosses of F1 hybrids produced by crosses between P. pacificus hermaphrodites and P. exspectatus males (c). The proportion of males among the mature progeny was calculated. The first column of the backcrosses is the result for F1 females without males to test their selfing fertility. P and E indicate P. pacificus and P. exspectatus, respectively. All replicates are shown as jitter plots while the box plots (upper whisker, the largest data point less than the third quartile+1.5×interquartile range; upper bound, the third quartile; centre line, median; lower bound, the first quartile; lower whisker, the smallest data point more than the first quartile−1.5×interquartile range) are shown when at least 5 data points exist. The sample number is shown in Supplementary Table 1.