Seed Lengths Corresponding to the Final Stage in Seed Abortion of Three Grain Legumes

Previous studies demonstrated that there is a final stage and a maximum dry weight for seed abortion in several grain legumes. In this work, the corresponding seed lengths were determined in soybean [ Glycine max (L.) Merr.], pea ( Pisum sativum L.), and white lupine ( Lupinus albus L.). Two genotypes with differing seed size were studied for each species, and the white lupine cultivar Lublanc was placed in two different growing conditions. A photographic technique based on the difference in light transmission between carpels and seeds was used to monitor in a nondestructive manner the lengthening of seeds in their pod. The fate of each seed (aborted vs. nonaborted) was recorded at maturity and time‐courses of seed length were determined from the photos for seeds of the two categories. The lengthening pattern followed by aborted and nonaborted seeds and the maximum lengths attained by each of these categories showed that there was a given length after which seed abortion did not occur. This length was close for the two cultivars of each species. For Lublanc, growing conditions influenced the average size of aborted seeds but did not change the length after which seed abortion did not occur. The respective maximum length of any aborted seed and the length not exceeded by 95% of aborted seeds were 12 and 10 mm for soybean, 8.5 and 6 mm for pea, and 13 and 11.5 mm for white lupine.