Figure 7.

The rel2-ref allele increases KRN. A) SEM images of B73 wild-type and +/rel2 ear primordia. Scale bars = 200 μm. SEM images were digitally extracted for comparison. The presence of a single mutant allele results in a significant increase in IM volume B). Concomitantly, heterozygous mutant inbred lines C) and D–G) A619 x B73 F1's display an increase in KRN relative to wild type controls without affecting kernel weight; only a subtle increase in length was observed in +/rel2 hybrids. H–J) 22 additional F1 hybrid combinations were tested for increased KRN. Of these, H) 7/22 displayed increased KRN in two to three environmental replicates without significant alterations in ear length I), though pleiotropic effects on kernel weight J) were observed. K) Representative image of M37W x B73 (+/+) and M37W x B73 (+/rel2) ears showing an increase KRN without morphological deformity of the ear. Scale bars = 1 cm. Quantification by two-tailed Student's t-test. Box plot center line corresponds to median; box limits, upper and lower quantiles; whiskers, maximum and minimum values; ns = nonsignificant (P > 0.05), * = P ≤ 0.05, ** = P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001.