The regulation of maternal investment in an indeterminate flowering plant ( Lotus corniculatus).

Lotus corniculatus regularly produces many more flowers than mature fruits. Number of inflorescences, number of flowers per inflorescence, proportion of flowers that initiate, abort, and develop fruits to maturity, number of seeds per fruit, and seed mass vary within and among individuals of this species. These components of maternal investment were measured under control, resource enriched (N-P-K fertilizer), and resource deprived (partial defoliation) conditions on a population of even-aged, similar-sized individuals. Resources rather than pollination limit the reproductive output of the plants. Flower number and seed yield are regulated during the reproductive episode in response to resource availability. L. corniculatus regulates flower number and seed yield under the different resource conditions primarily by altering the number of successive inflorescences/infructescences. Plants subjected to the 3 experimental treatments did not, however, differ in the proportion of flowers that produced a mature fruit or in the proportion of initiated fruits that matured (or aborted). On each treatment only 1 of every 3 flowers produced a mature fruit, and 3 of every 5 initiated fruits aborted. The ratio of flowers to fruits has thus been selected for reasons other than uncertainties in resource availability. The flowers that fail to produce a mature fruit could be functioning only as males, or they could be providing plants with a 'choice' of fruits to mature.-from Author