Contrasting Pollination Strategies and Breeding Systems in Two Native Useful Cacti from Southern Brazil.

Brazil is one of the centers of diversity of Cactaceae, yet studies addressing both pollination biology and the breeding system in Brazilian cacti are scarce. We herein present a detailed analysis of two native species with economic relevance: Cereus hildmannianus and Pereskia aculeata. The first species produce edible, sweet, spineless fruits and the second species produces leaves with high protein content. Pollination studies were undertaken through fieldwork observations in three localities of Rio Grande do Sul, Brazil, over two flowering seasons, totaling over 130 observation hours. Breeding systems were elucidated utilizing controlled pollinations. Cereus hildmannianus is solely pollinated by nectar-gathering species of Sphingidae hawk moths. In contrast, the flowers of P. aculeata are pollinated by predominantly native Hymenoptera but also by Coleoptera and Diptera, which gather pollen and/or nectar. Both cacti species are pollinator-dependent; neither intact nor emasculated flowers turn into fruit, yet whereas C. hildmannianus is self-incompatible, P. aculeata is fully self-compatible. In sum, C. hildmannianus is more restrictive and specialized regarding its pollination and breeding system, whereas P. aculeata is more generalist. Understanding the pollination needs of these species is a necessary starting point towards their conservation but also for their proper management and eventual domestication.

Determination of amino acid content, fatty acid profiles, and phenolic compounds in non-conventional edible fruits of seven species of palm trees (Arecaceae) native to the southern half of South America.

The fruits of palm trees (Arecaceae) are a very important food source for fauna and for humans, despite the still incipient role of these fruits in conventional diet. Seven palm tree species (plus one variety) that are native to the southern half of South America located east of the Andes (Argentina, Paraguay, Uruguay, and the southern states of Brazil) were studied. For the first time, the fatty acid profiles of palm seeds and the content of both amino acids and phenolic compounds present in the pulp (yellowish fleshy mesocarps) of the fruits were determined. High-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was used to screen and quantify thirty-two phenols and HPLC was used to determine the amino acid contents and fatty acids profiles of the species. Twenty-five percent of the fatty acids in the seeds of B. lallemantii, Butia odorata (var. pulposa), B. witeckii, and Syagrus romanzoffiana were found to be unsaturated. One species (B. lallemantii) had a high and well-balanced amino acid content (28,900 mg/kg), while six species (B. odorata, B. catarinensis, B. witeckii, Euterpe edulis, and Syagrus romanzoffiana) contained more than 14,000 mg/kg of amino acids. A high content of the phenolic compounds ferulic acid, luteolin, quercetin-3-rutinoside, isoquercetin, and isorhamnetin were found in many species, most notably in B. odorata, B. catarinensis, and B. witeckii.