Reproductive Biology of Varronia curassavica Jacq. (Boraginaceae)

Abstract

Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

Genetic and demographic aspects of Varronia curassavica Jacq. in a heterogeneous coastal ecosystem

“…In the population as a whole and in the dry lowland environment specifically, the fixation index was not significantly different from zero, evidencing the absence, or reduced effects, of inbreeding and genetic drift. This aspect can be explained by the reproductive system of the species, which is typically allogamic, with mechanisms of self-incompatibility, such as heterostyly and protogyny (Hoeltgebaum et al 2018). However, for the other environments, these values were negative and significant, indicating a tendency to preferential crosses or selection in favor of heterozygotes for this population.…”

“…For V. curassavica, the possible preference of crosses between more distant individuals, owing to heterostyly, would act as a promoter of the gene flow within the population, thus reducing the formation of internal genetic structure. In addition, gene flow for this species is also favored by an ample guild of insects that pollinate it (Hoeltgebaum et al 2018).…”

“…(Boraginaceae) is an important medicinal species widely used in folk medicine and also by the pharmaceutical industry owing to its anti-inflammatory, analgesic, and healing properties (Lorenzi & Matos 2008, Melo et al 2008, Bolzani et al 2012. It is a perennial subshrubby tetraploid species, insect-pollinated and dispersed mainly by birds (Opler et al 1975, Hoeltgebaum et al 2018, that exhibits self-incompatibility mechanisms, such as heterostyly and protogyny (Hoeltgebaum & Reis 2017, Hoeltgebaum et al 2018. It is found along most of the Brazilian coastline, as characteristic vegetation of coastal tropical and subtropical moist broadleaf forest, locally known as restinga (Smith 1970, Judd et al 2009.…”

Erva-Baleeira, Uma Possibilidade Real Da Sociobiodiversidade Para Modelos Sustentáveis De Produção

“…A disposição das folhas ocorre de forma alternada, raramente oposta, e a coloração verde da face adaxial é mais escura do que a face abaxial (Lorenzi;Matos 2008). Suas inflorescências são racemosas, formando-se em espigas curvadas para baixo com até 15 centímetros de comprimento com pequenas flores brancas, geralmente pentâmeras radiais e diclamídeas (Gilbert;Favoreto, 2012;Hoeltgebaum et al, 2018). De acordo com Hoeltgebaum et al (2018), as flores da erva-baleeira possuem curta duração, a abertura dos botões florais ocorre durante o dia e a murcha começa a ocorrer cerca de oito horas após a antese, aumentando gradativamente sua oxidação.…”

“…Suas inflorescências são racemosas, formando-se em espigas curvadas para baixo com até 15 centímetros de comprimento com pequenas flores brancas, geralmente pentâmeras radiais e diclamídeas (Gilbert;Favoreto, 2012;Hoeltgebaum et al, 2018). De acordo com Hoeltgebaum et al (2018), as flores da erva-baleeira possuem curta duração, a abertura dos botões florais ocorre durante o dia e a murcha começa a ocorrer cerca de oito horas após a antese, aumentando gradativamente sua oxidação. Apesar da murcha da corola, as estruturas reprodutivas e o estigma continuam ativos até a manhã seguinte, com o início de um novo ciclo reprodutivo.…”