Pollen morphology and viability of <i>Tillandsia</i> (Bromeliaceae) species by light microscopy and scanning electron microscopy

Aona

et al. 2021

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Tillandsia L. is the largest genus of the family Bromeliaceae, containing 755 species and seven subgenera. Morphoanatomical studies of leaves provide useful characteristics to phylogenetic, taxonomic, and ecological analyses. This study aims to characterize and compare the leaves of 24 species of the four subgenera of Tillandsia that occur in Bahia and also perform adaptative inferences to environmental responses.The results of the species' morphoanatomical studies were compared through dissimilarity analysis. The species have rosulate leaves with varying lengths and widths. The peltate trichomes present variation in the indument density and the length of their wing and central disk. The stomata are longitudinally distributed in one or both sides of the limb. The mesophyll is dorsiventral and presents aquiferous and chlorophyllic parenchymas. The vascular bundles are collateral and partially covered by fibers, except for Tillandsia linearis. Based on the dissimilarity analysis, it was possible to identify the formation of five groups. Group G1 was composed of T. linearis, which diverged from the other species of the subgenus. Group G2 was formed by the remaining species of the subgenus Phytarrhiza. G3 and G4 presented the species of the subgenus Diaphoranthema and Tillandsia, respectively. Group G5 gathered 11 species of the subgenus Anoplophytum and presented higher variability than the other subgenera. Based on the results, the morphoanatomical characteristics can be used to characterize and group Tillandsia species, besides confirming the morphological variability of these species to the epiphyte habit in different environments, especially xeric ones.

Section: Resultsmentioning

confidence: 99%

Leaf structure of Tillandsia species (Tillandsioideae: Bromeliaceae) by light microscopy and scanning electron microscopy

Oliveira

Aona

et al. 2021

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“…The number of pollen grains was estimated by counting the number of grains produced per flower in a Neubauer chamber, considering the existence of five anthers in the two different floral morphs. We collected three flowers, each from a different plant, and stored the anthers individually in Eppendorf ® tubes, according to the method described by Kearns and Inouye (1993) and Souza et al (2021).…”

Section: Morphology and Morphometry Of The Reproductive Organsmentioning

confidence: 99%

“…The pollen viability was analyzed according to the in vitro germination technique and histochemical test. Three flowers were collected at anthesis (6:00 h) from three different plants of the two floral morphs For in vitro germination, the pollen grains were spread with a soft brush and uniformly distributed in Petri dishes containing 25 ml of BK culture medium (Brewbacker and Kwack, 1963) with 20% sucrose and kept in a dark chamber at temperature of 27 ± 1 C. Twelve repetitions were used, with each repetition being represented by three Petri dishes, each subdivided into four quadrants as described by Souza et al (2021).…”

Section: Pollen Viabilitymentioning

confidence: 99%

Phenology, floral and reproductive biology of Dichorisandra rhizantha Aona (Commelinaceae), an endemic endangered species in an Atlantic Forest fragment

JÚNIOR

Costa

et al. 2023

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Commelinaceae is an important component of the Atlantic Forest and its analysis can provide information on the conservation of that species. This study had the objective of analyzing the phenology and floral and reproductive biology of Dichorisandra rhizantha, growing in an Atlantic Forest fragment, to obtain data related to the form of reproduction and pollination mechanism of this species. We monitored the phenophases and reproductive biology of the D. rhizantha in the area studied using different methodologies and microscopy techniques (LM, SEM and FM). The flowering period occurs during the dry season. The species is andromonoecious and has daytime anthesis (4:30 a.m.-1:30 p.m.). It has purple zygomorphic flowers and rimose but functionally poricidal anthers. The pollen viability was 97.6% and the two floral morphs investigated contained a large quantity of pollen grains. The time of greatest stigma receptivity (anthesis) coincided with the pollen viability. Cross-pollination was the only efficient reproductive system of the species, with observation of gametophytic self-incompatibility and pollen tubes growth only as far as the middle or lower third of the pistil. We observed bee species of the genera Xylocopa and Euglossa visiting the flowers and acting as effective pollinators. The immature fruits were formed after about 3.25 ± 1 days, and the presence was noted of ants of the genus Cephalotes acting as dispersers of the seeds, with aril serving as the reward. Although the natural reproductive system is efficient, D. rhizantha is endangered, mainly due to fragmentation of habitat caused by deforestation and urban encroachment.

“…Several techniques can be used for identification, characterization and illustration of the morphological traits of plants, to provide detailed knowledge of the structures of interest (Souza et al, 2021; Zahra et al, 2021). Scanning electron microscopy and light microscopy can be employed to differentiate the closely related taxonomic and micromorphological traits of genera or species and develop descriptive terms for traits related to the various structures and organs of plants (Ahmad et al, 2020; Zahra et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Seed morphoanatomy of the genus PassifloraL. (Passifloraceae) by scanning electron microscopy and light microscopy

Silva

Junghans

et al. 2022

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Morphoanatomical analysis of seeds contributes to knowledge of the development of seedlings and identification of species, as well as supporting conservation studies. The conservation of the species belonging to the Passiflora genus is crucial due to of the threats to the genetic resources of these species. Thus, the objective of this study was to morphoanatomically characterize Passiflora seeds, verify possible injuries to the tissues after cryopreservation and thus contribute to the conservation strategies of the species of this genus. Initially, seeds of Passiflora coccinea, P. edulis, P. gibertii, P. maliformis, P. morifolia, P. setacea, P. suberosa, and P. tenuifila collected from the Passion Fruit Active Germplasm Bank of the Embrapa Cassava and Fruits research unit (Embrapa Mandioca e Fruticultura) were analyzed. Then, their length, width and thickness, shape of the base and tip, and ornamentations present on the body and edge of the seeds were evaluated. The seeds of the species were placed in cryotubes and immersed in liquid nitrogen to assess possible cryoinjuries. The tegument and tissues of the seeds were examined by scanning electron microscopy. The seeds had varied biometric data, with average values of 4.63 mm for length, 3.28 mm for width, and 1.51 mm for thickness. Six ornamentation types were observed: reticulate for the species P. coccinea; finely reticulate for P. edulis; foveolate reticulate for P. gibertii and P. setacea; alveolate reticulate for P. maliformis and P. tenuifila; coarsely reticulate for P. morifolia; and falsifoveolate reticulate for P. suberosa. Some seeds suffered tegument cracks due to the freezing in liquid nitrogen, but without physiological damages to the embryo and endosperm. The cryopreservation of the seeds in the presence of the tegument significantly reduced the cryoinjuries caused to the embryo. Cryopreservation can be promising for long-term conservation of passion fruit seeds.