Figure 1.

Phenotype classification scheme for hybrid seeds and influence of maternal genotype in the A. thaliana × A. arenosa cross. A, Four phenotypic classes were observed in the output from the hybrid crosses: shriveled, green, viviparous, and normal seed. The mature phenotype of these seeds corresponds to defects in major transitions in seed development. B, Visualization of a C24 × A. arenosa 10-DAP silique shows normal and shriveled seeds. The normal seed has an embryo (EM) that fills the seed compartment, whereas the shriveled seed has an embryo arrested in the heart stage. C, The maternal A. thaliana genotype used in the cross to A. arenosa is indicated on the x axis. Bar heights represent mean %NGV values, and se is displayed as black error bars. Significant differences between genotype mean values (P = 0.05) are represented by different letters above the bars (same letter, no significant difference in mean value). Mean numbers are based on data from 15 plants (approximately 1,500 seeds) for each of the Col-0, C24, and F1 crosses, 80 plants (approximately 22,900 seeds) for BC1-Col-0, and 91 plants (approximately 23,300 seeds) for BC1-C24.