Stigma structure and receptivity in Bromeliaceae

et al. 2017

Acta Bot. Bras.

Alcantarea nahoumii occurs exclusively in the state of Bahia, Brazil, and is classifi ed as vulnerable due to deforestation and frequent fi res in the region. Knowledge of fl oral and reproductive biology is fundamental to understanding ecological interactions, as well as the reproductive success of plant species. Th e objective of this study was to evaluate the fl oral and reproductive biology of A. nahoumii in an Atlantic Forest fragment with regard to phenology, pollen viability, stigma receptivity, pollination ecology and reproductive systems, all of which are important parameters for of the development of conservation strategies for the species. Anthesis is diurnal and heterogeneous, starting at 6:30 a.m. and lasting until 8:00 a.m. Highest germination percentages and greatest pollen tube lengths were obtained in BK culture medium. Histochemical tests revealed high pollen viability (89.71 %). Stigma receptivity occurred during anthesis and lasted for up to 24 hours after fl oral opening. Alcantarea nahoumii exhibited preferential allogamy and self-compatibility, and required a pollinator to production of viable seeds. Sixteen species of pollinators were observed visiting A. nahoumii, among which were fi ve hummingbird species. Even though its reproductive system is effi cient, this bromeliad remains threatened mainly due to habitat fragmentation caused by deforestation, burning and predatory extractivism.

Section: Stigma Receptivitysupporting

confidence: 92%

Section: Stigma Receptivitymentioning

confidence: 96%

Floral and reproductive biology of Alcantarea nahoumii (Bromeliaceae), a vulnerable endemic species of the Atlantic Forest

Bastos

et al. 2017

Acta Bot. Bras.

“…Stigma receptivity has been studied in a number of ornamental plants such as Melaleuca alternifolia (Baskorowati, 2009), Mesosetum chaseae (Silva et al, 2013), Aechmea sp., Ananas sp., Alcantarea nahoumii, Pseudananas sagenarius and Vriesea sp. (Souza et al, 2016) and Lilium sp. (He et al, 2017).…”

Section: Stigma Receptivitymentioning

confidence: 99%

Pollen viability and stigma receptivity in Swainsona formosa (G.Don) J.Thompson (Fabaceae), an ornamental legume native to Australia

Ichwan

Eliyanti

Swari

2019

Pollen viability and stigma receptivity are prerequisites for successful cross-pollination and seed set in Swainsona formosa. In this study, the pollen viabilities and stigma receptivities was assayed by in vitro pollen germination and simple hand-pollination method on glasshouse-grown plants, respectively. The viability of pollen grains was tested under three different storage conditions: 1) pollen grains were left on the plant in the glasshouse under natural conditions, 2) pollen grains were harvested and kept at a low temperature (4 o C) in total darkness, and 3) pollen grains were kept in a dry freezer (-10 o C) and in total darkness. Meanwhile, stigma receptivity was determined by hand-pollination using fresh pollen grains on flower of glasshouse-grown plants at one day before anther dehiscence up to 8 days after anther dehiscence. The results showed that pollen grains could be stored at 4 o C for up to 28 days without significantly losing their viability. Pollen longevity could be extended beyond two months when stored at -10 o C and under dry conditions. These findings provided a simple and economically sound method for storage of S. formosa pollen. In addition, stigma receptivity was found to be receptive from one day before anther dehiscence and reached its peak within four days after anther dehiscence. These results provide a valuable background to the conventional breeding of this species to create hybrids through cross-pollination

“…The ecological and economic importance of Tillandsia species, together with their risk of extinction due to habitat degradation and predatory extravism, justify studies of their morphology, to support efforts for management and conservation. Knowedge of the floral and reproductive biology is fundamental to understand the ecological relations and define suitable techniques for controlled cross‐breeding and subsequent obtainment of seeds (Souza et al , Bastos et al ).…”

Section: Introductionmentioning

confidence: 99%

Morphoanatomy and stigma receptivity in Tillandsia L. (Bromeliaceae) occurring in Bahia, Brazil

Oliveira

Nordic Journal of Botany

et al. 2020

Self Cite

Species of Tillandsia L. are widely distributed in Brazilian ecosystems, and in the state of Bahia they can be found in the Atlantic Forest, Caatinga and Cerrado biomes. Studying the reproductive aspects of these species can support their management and conservation. In particular, stigma morphology is a conserved trait of Bromeliaceae and stigma receptivity can influence the success of pollination. The objective of this study was to characterize the morphoanatomy and classify the stigma types of Tillandsia species by means of light and scanning electron microscopy, as well as to evaluate the stigma receptivity by different methods and at three floral development stages. A total of 21 Tillandsia species found in Bahia were evaluated. The stigma receptivity was assessed with hydrogen peroxide (3%) and a solution of α‐naphthyl acetate. Four stigma types were observed: conduplicate‐spiral for the species of the Tillandsia subgen. Tillandsia, simple‐erect for species of T. subgen. Diaphoranthema, and simple‐truncate for the species of T. subgen. Phytarrhiza. The species of the T. subgen. Anoplophytum had three morphological types, conduplicate‐spiral, conduplicate‐patent and simple‐erect. All the species had trifid stigmas, monostratified epidermis, numerous idioblasts containing raphides in the fundamental parenchyma and an individual vascular bundle for each carpel. In all the species studied by the two methods of stigma receptivity the highest enzyme activity was observed during anthesis. The morphoanatomy of the stigma and style provides important information for the taxonomy of Tillandsia and the data on stigma receptivity can support studies of the reproduction and conservation of these species.