2 resultados para Effective Pollen Dispersal
em Digital Commons at Florida International University
Resumo:
Jackfruit (Artocarpus heterophyllus Lam.) is a multi-purpose fruit tree, native to tropical Asia. It was introduced to South Florida in the early 1900s but has had little commercial importance. In recent years, there has been an increased interest in jackfruit as a commercial crop in South Florida, but there has been little scientific investigation conducted. The pollination mechanism was not clearly understood. This study focused on jackfruit breeding using 'Dang Rasimi' and 'Cheena' cultivars. Controlled hand-pollinations revealed that both cultivars were not apomictic. Both cultivars set fruit with self-pollination, but seed set and many fruit characters such as size, flesh percentage and edible percentage were greatly enhanced with cross-pollination. I conclude that jackfruit are outbreeding plants. Tests for pollen dispersal by wind were inconclusive. A variety of insects were collected, but few had a role in pollination. My results suggest that jackfruit are likely to have insect-assisted wind pollination in South Florida. ^
Resumo:
Saurochory (seed dispersal by reptiles) among crocodilians has largely been ignored, probably because these reptiles are generally assumed to be obligate carnivores incapable of digesting vegetable proteins and polysaccharides. Herein we review the literature on crocodilian diet, foraging ecology, digestive physiology and movement patterns, and provide additional empirical data from recent dietary studies of Alligator mississippiensis. We found evidence of frugivory in 13 of 18 (72.2%) species for which dietary information was available, indicating this behavior is widespread among the Crocodylia. Thirty-four families and 46 genera of plants were consumed by crocodilians. Fruit types consumed by crocodilians varied widely; over half (52.1%) were fleshy fruits. Some fruits are consumed as gastroliths or ingested incidental to prey capture; however, there is little doubt that on occasion, fruit is deliberately consumed, often in large quantities. Sensory cues involved in crocodilian frugivory are poorly understood, although airborne and waterborne cues as well as surface disturbances seem important. Crocodilians likely accrue nutritional benefits from frugivory and there are no a priori reasons to assume otherwise. Ingested seeds are regurgitated, retained in the stomach for indefinite and often lengthy periods, or passed through the digestive tract and excreted in feces. Chemical and mechanical scarification of seeds probably occurs in the stomach, but what effects these processes have on seed viability remain unknown. Because crocodilians have large territories and undertake lengthy movements, seeds are likely transported well beyond the parent plant before being voided. Little is known about the ultimate fate of seeds ingested by crocodilians; however, deposition sites could prove suitable for seed germination. Although there is no evidence for a crocodilian-specific dispersal syndrome similar to that described for other reptiles, our review strongly suggests that crocodilians function as effective agents of seed dispersal. Crocodilian saurochory offers a fertile ground for future research.