Does successful ovule development depend on its position within the pod? Examples from Neotropical Fabaceae

Abstract

Previous studies have shown a nonrandom pattern of ovule fate probabilities according to ovule position in legume pods. Here, we tested how ovule position within the pods of two Fabaceae affects its fate. We expected higher proportion of well-formed seeds near the fruit tips and of unfertilized and aborted ovules near fruit bases. We collected pods of Poincianella pyramidalis and Anandenanthera colubrina in a seasonal dry forest in northeastern Brazil and recorded total pod length and ovule number, position, and fate (unfertilized, well formed, aborted, and predated). The proportion of well-formed ovules at fruit tips was significantly higher than at fruit bases in P. pyramidalis. The opposite pattern was found for unfertilized and aborted ovules, thus corroborating our hypothesis. However, the probability of seed predation in A. colubrina was significantly higher in pod tips, thus providing moderate support for our hypotheses. Interspecific differences in the patterns of ovule fate are likely to be driven by species pollination systems. We tested how ovule position within the pods of Poincianella pyramidalis and Anandenanthera colubrina affects its fate. A higher number of well-formed ovules at fruit tips and lower number of unfertilized and aborted ovules in fruit bases was found only for P. pyramidalis. Interspecific differences in the patterns of ovule fate are likely to be driven by species pollination systems.