Enantiostyly is a form of reciprocal herkogamy, in which floral morphs present reciprocal differences in the position of sexual elements, and occurs in monomorphic and dimorphic forms. This polymorphism maximises cross-pollination and reduces self-pollination, being very common within the subtribe Cassiinae (Fabaceae). Nevertheless, few studies have investigated the functionality of enantiostyly, particularly in this plant group. The present study aimed to investigate enantiostyly and its functionality in Chamaecrista ramosa, a monomorphic enantiostylous shrub, in an area of coastal vegetation in northeast Brazil. Pollen deposition and capture on the body of floral visitors, the relationship of these data with floral biology and breeding system, and morph ratio were evaluated. Pollen deposition and capture occurred in specific sites of the floral visitor body, showing the functionality of enantiostyly. The floral architecture, associated with the floral visitor behaviour, resulted in indirect pollen deposition on the floral visitor body. This occurred through a loop made by the pollen upon the inner petal surface, similar that generally reported for other Cassiinae. Chamaecrista ramosa is self-compatible, although no fruit set was observed through spontaneous self-pollination. The occurrence and number of floral morphs was similar within clumps. Enantiostyly seems to be advantageous for this species, as it results in efficient pollen capture and deposition, reduces the chances of autogamy and maximises intermorph pollen flow.

The results indicate the occurrence of an atypical enantiostyly in C. flexuosa. This seems to improve reproductive success by increasing the efficiency of pollen deposition and capture.

-(Reproductive biology of catingueira (Caesalpinia pyramidalis Tul., Leguminosae-Caesalpinioideae), an endemic species of Caatinga). The Leguminosae comprises 293 species in the Caatinga, and only eight were studied for pollination and, or breeding system. We analysed the floral biology, pollinators and breeding system of Caesalpinia pyramidalis Tul. The pollen tube growth was observed eight, 24 and 48 hours after hand pollinations. There were 5.7 ± 0.9 ovules/flower, 66.9 ± 47.8 flowers and 2.1 ± 1.2 fruits per inflorescence and 2.88 ± 1.44 seeds/fruit. Nectar production was about 1.0 µL during the first day of anthesis, 0.5 µL in the second day, and there was no production in the third day. C. pyramidalis is self-incompatible but self-pollen tubes grew down to the embryo sac. Species of Xylocopa and Centris are important pollinators of C. pyramidalis. During the visits, the bees promote mostly geitonogamy which favours the loss of fruits, and generates a low fruit/flower ratio (0.03). However, high seed/ovule ratio (0.50) shows highest investment in seeds by cross-pollination, reducing the effects of geitonogamy.Key words -Caatinga, Centris, late-acting self-incompatibility, preemergent reproductive success, Xylocopa RESUMO -(Biologia reprodutiva da "catingueira" (Caesalpinia pyramidalis Tul., Leguminosae-Caesalpinioideae), uma espécie endêmica da Caatinga). Leguminosae está representada na Caatinga por 293 espécies, das quais oito foram estudadas quanto à polinização e/ou sistema reprodutivo. Foram analisados a biologia floral, os polinizadores e o sistema reprodutivo de Caesalpinia pyramidalis Tul. Houve produção de 5,7 ± 0,9 óvulos/flor, 66,9 ± 47,8 flores e 2,1 ± 1,2 frutos por inflorescência e 2,88 ± 1,44 sementes/fruto. O volume de néctar foi cerca de 1,0 µL durante o primeiro dia da flor, 0,5 µL no segundo dia, não havendo produção no terceiro dia. C. pyramidalis é auto-incompatível, com tubos polínicos oriundos de autopolinização manual crescendo até o saco embrionário. Espécies de Xylocopa e Centris constituem importantes polinizadores de C. pyramidalis. Durante as visitas, as abelhas promovem principalmente geitonogamia, a qual favorece a perda de frutos e leva à baixa razão fruto/flor (0,03). Entretanto, a razão semente/óvulo relativamente elevada (0,50), demonstra maior investimento em sementes provenientes de polinizações cruzadas, reduzindo os efeitos da geitonogamia.Palavras-chave -auto-incompatibilidade de ação tardia, Caatinga, Centris, sucesso reprodutivo pré-emergente, Xylocopa

Phenology and reproductive biology of cultivated species are important for the comprehension of the requirements for fruit and seed production and the management of pollinators. This study aimed to characterise the phenology, reproductive biology and growing degree days of the grapevine 'Isabel' (Vitis labrusca) in northeastern Brazil during January 2011 (P1), Augst 2011 (P2), April 2012 (P3) and August 2012 (P4). We recorded the duration (days) of the phenological stages, pruning (P), woolly bud (W), budburst (B), inflorescence development (ID), flowering (F), ripening (R) and harvest (H). We analysed the floral biology, the sexual system and the breeding system. We measured the growing degree days (GDD) required to reach the subperiods P-B, B-F and F-H. The periods P1, P2, P3 and P4 lasted for 116, 125, 117 and 130 days, respectively. The number of days of harvest were similar in the same dry (P1 and P3) and rainy (P2 and P4) periods. All the periods that we recorded were shorter than those observed in other regions of Brazil, which may be attributable to the mean temperature and carbohydrate metabolism. The flowers are green, hermaphroditic, with an odour of mignonette, low pollen viability and autogamous. The base temperature of 10°C was considered the most adequate for the subperiods as has been documented for other grape varieties in Brazil. Thus, temperature was also the most adequate for the cycles, presenting a smaller standard deviation (0.119, 0.147, 0.156 and 0.153 to P1, P2, P3 and P4, respectively) when compared to a base temperature of 12°C (0.122, 0.158, 0.165 and 0.160 to P1, P2, P3 and P4, respectively). The higher and the lower observed GDD were 1972.17 and 1870.05, respectively, both above the values recorded in other parts of Brazil for same variety. The phonological results, including knowledge of growing degree days, are important to the planning of cultures at the study site and in other regions that have similar climatic conditions and make it possible to pre-determine the harvest.Keywords: breeding system, heat unit, grape, phenology, GDD. Fenologia, biologia reprodutiva e graus-dias da videira "Isabel" (Vitis labrusca, Vitaceae) cultivada no nordeste do Brasil ResumoFenologia e biologia reprodutiva de espécies cultivadas são importantes para a compreensão dos requerimentos para a produção de frutos e sementes, bem como para o manejo de polinizadores. O presente estudo objetivou caracterizar a fenologia, a biologia reprodutiva e a exigência térmica (graus-dias) da videira "Isabel" (Vitis labrusca) no nordeste do Brasil, durante janeiro/2011 (P1), Agosto/2011 (P2), Abril/2012 (P3) e Agosto/2012 (P4). Analisamos a duração (dias) dos estádios fenológicos poda (PO), gema-algodão (GA), brotamento (BR), aparecimento da inflorescência (AI), florescimento (FL), início da maturação (IM) e colheita (CO). Analisamos a biologia floral, o sistema sexual e o sistema reprodutivo. As exigências térmicas foram obtidas em termos de graus-dia (GD) necessários para atingir os subperíodos PO-BR, BR-...

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-(Reproductive phenology, floral biology and pollinators of two sympatric species of Marantaceae from an Atlantic forest fragment, northeastern Brazil). We analyzed the flowering, fruiting and the pollination biology of two species of Marantaceae: Ischnosiphon gracilis (Rudge) Koern. and Stromanthe porteana A. Gris. Observations were carried out in natural populations at the "Parque Estadual Dois Irmãos" (8º7'30" S and 34º52'30" W), a remnant of Atlantic forest in Pernambuco. We verified a continuous phenological pattern in both species, with different flowering and fruiting peaks. Inflorescences of I. gracilis produced 14.4 ± 3.4 flowers and 1.3 ± 0.6 fruits whereas S. porteana produced 125.4 ± 14.8 flowers and 7.4 ± 4.9 fruits. We verified low pollen/ovule ratio and reduced fruit set under natural pollination for the studied species. Sugar concentration in the nectar of I. gracilis flowers was high (26%-32%), characteristic of bee flowers, and in S. portena the nectar was less concentrated (20%), common to hummingbird flowers. Ischnosiphon gracilis is pollinated by three species of Euglossini bees (Euglossa sp., Eulaema bombiformis and E. cingulata), whereas S. porteana is pollinated by one species of Euglossini bee (Eufriesea surinamensis) and two species of hummingbirds (Phaethornis ruber and Amazilia versicolor). The differences between the flowers of these species avoid the sharing and competition for pollinators, which can assure their maintenance in the habitat. However, in a long term, the low fruit set can affect the population structure by decreasing the reproductive success of these species.Key words -Euglossini, Ischnosiphon gracilis, melittophily, ornithophily, Stromanthe porteana RESUMO -(Fenologia reprodutiva, biologia floral e polinizadores de duas espécies simpátricas de Marantaceae em um fragmento de Floresta Atlântica, Nordeste do Brasil). Foi analisada a floração, a frutificação e a biologia da polinização em duas espécies de Marantaceae: Ischnosiphon gracilis (Rudge) Koern. e Stromanthe porteana A. Gris. As observações foram realizadas em populações naturais no Parque Estadual Dois Irmãos (8º7'30" S e 34º52'30" W), um remanescente de Floresta Atlântica em Pernambuco. Nas duas espécies foi verificado padrão fenológico contínuo, com diferentes picos de floração e frutificação. As inflorescências em I. gracilis produziram 14,4 ± 3,4 flores e 1,3 ± 0,6 frutos, enquanto em S. porteana, produziram 125,4 ± 14,8 flores e 7,4 ± 4,9 frutos. Foram verificadas baixa razão pólen/óvulo e reduzida produção natural de frutos nas duas espécies. Em I. gracilis, a concentração de açúcares no néctar foi alta (26%-32%), característica de flores visitadas por abelhas e em S. porteana o néctar foi menos concentrado (20%), situação comum em flores visitadas por beija-flores. Ischnosiphon gracilis é polinizada por três espécies de abelhas Euglossini (Euglossa sp., Eulaema bombiformis e E. cingulata), enquanto S. porteana é polinizada por uma espécie de abelha Euglossini (Eufriesea surinamensis) e por duas ...

Inducement to stamen movement by oligolectic bees has been reported for some Loasaceae species; however, detailed research studies on the pollination ecology of species in the genus Aosa are absent. In this study, we analyzed the floral biology and breeding system of Aosa rupestris (Hook.) Weigend, focusing on the role of pollinators in inducing stamens' movements. We described the anthesis, the behavior of floral visitors, and carried out reproductive experiments in a population in a dry forest (''caatinga'') area in Northeastern Brazil. We carried out four experiments and one control to establish whether the interval between the movements of two successive stamens is regulated by pollinator visits. Anthesis lasted for 3-4 days. Stamens (102 ± 12.57) remained with closed anther inside petals early in the anthesis, after which they moved to the center of the flower and presented its pollen (male phase). After all stamens have reached the center of the flower, the female phase started. Bicolletes nordestina Urban, 2006 was the only floral visitor to A. rupestris flowers, drinking nectar, collecting pollen, or sleeping on the flowers. Aosa rupestris was autogamous, but fruit set was higher under natural conditions. The interval between movements of two successive stamens was not different among experiments. Therefore, stamen movements were spontaneous and did not respond to pollinator visits, in contrast to the pattern of stamen movements observed in other Loasaceae species. Although A. rupestris is autogamous, floral structure and behavior of the oligolectic bee pollinator ensured the highest level of fruit set in this species.

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