scholarly journals Floral biology of Sesbania virgata: an invasive species in the Agreste of Paraíba, northeastern Brazil

Rodriguésia ◽  
2016 ◽  
Vol 67 (4) ◽  
pp. 871-878 ◽  
Author(s):  
Vênia Camelo de Souza ◽  
Leonaldo Alves de Andrade ◽  
Zelma Glebya Maciel Quirino

Abstract Although reproduction seems to play an important role in the successful invasive strategy of Sesbania virgata, its floral biology is poorly known. We aimed at filling this gap by studying the floral biology of a population of S. virgata in the Agreste of Brazil. Sesbania virgata is a shrub that bears racemose inflorescences. Its flowers are zygomorphic, pedunculate, hermaphrodite, and have a pale yellow corolla, diadelphous androecium, anthers with longitudinal dehiscence, and inconspicuous stigma. S. virgata flowers display three different types of petals: banner (11.92 mm), wing (8.27 mm), and keel (9.3 mm). The flowering peak occurred from November to January. The average number of pollen grains per flower was 22,918, with a pollen viability of 99.93%. Its anthesis is diurnal and asynchronous. Although S. virgata is autogamous, its pollen/ovule ratio suggests that this plant has a mixed reproductive system (xenogamy + autogamy). Continuous flowering, flower morphology, and specialized breeding system are essential to assure the reproductive success of this species in the studied habitat. Sesbania virgata is a food source for flower visitors, due to its continuous flowering and large population. Therefore, it has an effective reproductive strategy that assures its invasion success.

2016 ◽  
Vol 76 (4) ◽  
pp. 975-982 ◽  
Author(s):  
N. A. S. Nunes ◽  
A. V. Leite ◽  
C. C. Castro

Abstract 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.


2022 ◽  
Vol 28 (1) ◽  
pp. 92-98
Author(s):  
Cristiane Gonçalves Souza ◽  
Sabrina Maihave Barbosa Ramos ◽  
Silvia Nietsche ◽  
Clivia Carolina Fiorilo Possobom ◽  
Elka Fabiana Aparecida Almeida ◽  
...  

Abstract Adenium obesum (Forssk.) Roem. & Schult., popularly known as desert rose, has become a valuable ornamental plant. In floriculture, the production of hybrids is prioritized. Hence, knowledge on floral biology and sexual reproduction of the target species is fundamental. The objectives of this study were: (1) to test sucrose concentrations and temperatures for in vitro germination of A. obesum pollen grains; (2) to identify the effect of temperature on the viability of A. obesum pollen grains; and (3) to evaluate the viability of pollen grains and stigma receptivity in pre-anthesis, at flower opening, and 72 h post-flower opening in three accessions of A. obesum. A significant relationship between temperatures and sucrose concentrations was observed in the in vitro germination test. The highest percentage of in vitro germination of pollen grains, 39.81%, was observed at an estimated temperature of 26.05 °C. Desert rose accessions maintained in biochemical oxygen demand (BOD) chambers at 30 °C during a 16-h light photoperiod showed faster flowering, and temperatures ≥ 25 °C induced pollen grain viability percentages above 69%. Temperature is one of the most important abiotic factors, influencing mainly in pollen germination, pollen tube growing and in efficiency fertilization. The ICA-wd accession stood out and can be considered a pollen donor in artificial pollination. The stigmas of flowers were receptive from a day before flower opening until three days after. The two parameters presented above, stigma receptivity and pollen viability, allow inferences about the appropriate time for successful pollination and subsequent fertilization in desert roses.


Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 919-926 ◽  
Author(s):  
Jacilene Bezerra da Silva ◽  
Ana Virgínia de Lima Leite

Abstract Reproductive biology and pollination of the fanwort, Cabomba aquatica Aubl., were studied in populations from dams located in Dois Irmãos State Park, Recife, Pernambuco state, northeastern Brazil. Flower anthesis in this species is diurnal and lasts two days. The flowers are bisexual and exhibit herkogamy and incomplete protogyny. Each flower produces an average of 2.1 ± 94.8 pollen grains, with a P/O ratio of 1.055 and high pollen viability (99.7%). This species is self-compatible, but requires biotic vectors to transfer pollen. We observed visits of bees (Apidae and Halictidae), wasps (Vespidae) and flies (Diptera) to the flowers. Bees and wasps were considered to be effective pollinators, both due to their behavior and their high frequency of visits to flowers, whereas flies were considered to be occasional pollinators. The floral mechanism (herkogamy and protogyny), together with low nectar production and pollinator behavior during visits, may contribute to increase pollen flow between individuals.


2010 ◽  
Vol 70 (3) ◽  
pp. 671-676 ◽  
Author(s):  
FO. Silva ◽  
SD. Kevan ◽  
N. Roque ◽  
BF. Viana ◽  
PG. Kevan

We present the first records on pollination biology of Jacquemontia montana (Moric.) Meisn. (Convolvulaceae), a widespread climber in the Chapada Diamantina. Our objectives were to (1) characterise flower morphology and biology of J. montana; (2) sample flower visitors and (3) make inferences about potential pollinators, based on foraging behaviour. Observations and sampling were performed on two patches from 8:00 AM to 3:30 PM, May 15th to 16th, 2007. The corolla is bowl shaped, pentamerous, gamopetalous, actinomorphic, and yellow, with a mean diameter of 22.43 ± 1.81 mm, the depth being variable during flower phases. Stigma receptivity lasted from 8:00 AM-3:30 PM and pollen viability from 9:00 AM-3:30 PM Pollen. showed great decline in number but not in viability during anthesis. Nectarivorous (Coleoptera, Diptera, Hymenoptera) and herbivorous (Orthoptera) insects were found on the flowers. Both male and female bees (Dialictus spp., Robertson 1902) were the most frequent flower visitor. The bees' behaviour, and time spent on flowers, varied according to the resource gathered (i.e., pollen or nectar). The Dialictus species are likely to be the main pollinator of J. montana, considering the frequency, contact with reproductive parts, and carrying only J. montana pollen spread over the ventral part of the thorax, abdomen and legs. Although not quantified, nectar may still be available in the afternoon, considering the behaviour of bees on flowers during this time. Pollen:ovule ration that was1.200:4, suggests facultative xenogamy.


Author(s):  
Ivan Sérgio da Silva Oliveira ◽  
Vênia Camelo de Souza ◽  
Sara Beatriz da Costa Santos ◽  
Jazielly Nascimento da Rocha Almeida ◽  
Josinaldo da Silva Henrique ◽  
...  

Yellow passion fruit is a native tropical fruit tree whose cultivation has evolved very rapidly in Brazil; therefore, studies on the ecology of reproduction are needed. The study of pollen viability is an important tool to observe the male potential of the species. The objective of this study was to estimate pollen viability, pollen/ovule ratio and floral biology of Passiflora edulis Sims in organic cultivation located in Bananeiras, PB, and Brazilian. The study was developed in a completely randomized design, using ten flower buds in the pre-anthesis. The analyses performed in the biology laboratory of the Center of Human, Social and Agrarian Sciences of the Federal University of Paraiba. For the pollen viability analysis, all the anthers of the ten flower buds were used, five anthers per flower, which were crushed on a glass slide and with the aid of Alexander dye, the purple pollen grains were considered viable and the green ones unviable. To measure flower morphology and biometrics, a digital pachymeter, analytical balance and ruler were used. Five stamens form the androecium; the fillets are of short length inserted below the ovary. The flowers have three stigmas with an average height of 16.5mm, an average of 32,136 viable pollens, 58 unviable pollen grains and 140 ovules per ovary, having a pollen viability of 99.8% and a pollen/ovule ratio of approximately 95/1 pollen grains per ovule. Their structures are uniform, with no biometric variations in the amount of petals, sepals, anthers and stigma length. Alexander's reactive dye was effective in staining the pollen grains of yellow passion fruit. The pollen/ovule ratio indicates that this species performs facultative autogamy as well; however, this classification alone is not sufficient to affirm its reproductive system.


Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 290
Author(s):  
Abdul Kader Alabdullah ◽  
Graham Moore ◽  
Azahara C. Martín

Although most flowering plants are polyploid, little is known of how the meiotic process evolves after polyploidisation to stabilise and preserve fertility. On wheat polyploidisation, the major meiotic gene ZIP4 on chromosome 3B duplicated onto 5B and diverged (TaZIP4-B2). TaZIP4-B2 was recently shown to promote homologous pairing, synapsis and crossover, and suppress homoeologous crossover. We therefore suspected that these meiotic stabilising effects could be important for preserving wheat fertility. A CRISPR Tazip4-B2 mutant was exploited to assess the contribution of the 5B duplicated ZIP4 copy in maintaining pollen viability and grain setting. Analysis demonstrated abnormalities in 56% of meiocytes in the Tazip4-B2 mutant, with micronuclei in 50% of tetrads, reduced size in 48% of pollen grains and a near 50% reduction in grain number. Further studies showed that most of the reduced grain number occurred when Tazip4-B2 mutant plants were pollinated with the less viable Tazip4-B2 mutant pollen rather than with wild type pollen, suggesting that the stabilising effect of TaZIP4-B2 on meiosis has a greater consequence in subsequent male, rather than female gametogenesis. These studies reveal the extraordinary value of the wheat chromosome 5B TaZIP4-B2 duplication to agriculture and human nutrition. Future studies should further investigate the role of TaZIP4-B2 on female fertility and assess whether different TaZIP4-B2 alleles exhibit variable effects on meiotic stabilisation and/or resistance to temperature change.


2013 ◽  
Vol 85 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Saulo M. Sousa ◽  
Patrícia M.O. Pierre ◽  
Giovana A. Torres ◽  
Lisete C. Davide ◽  
Lyderson F. Viccini

The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen grains and a single species exhibited, only tetracolporate pollen. The amb ranged from triangular to square, and the shape varied from oblate-spheroidal to prolate-spheroidal. Three different types of exine ornamentation were observed: psilate, scabrate and perforate. In addition to morphological data, we found positive association between the chromosome numbers and size of pollen grains, and also between the length and width of the colpi. The results indicate that the characteristics of pollen grains in Lippia may be used as an additional taxonomic character of the genus.


2012 ◽  
Vol 40 (2) ◽  
pp. 53 ◽  
Author(s):  
Cevriye MERT

This study reports on the arrangement of flower buds and structure of floral organs of cornelian cherry (Cornus mas L.) cultivars local to Turkey. The local cultivars were investigated under stereo microscope, light microscope, and scanning electron microscope (SEM). The results indicate that each node has two oppositely positioned buds on 1-year-old shoot. Inflorescences resembled the umbel structure that enclosed four (two sets of oppositely oriented) bud scales. The mean flower number varied between 16.3 and 19.9 per cluster among the cultivars. The flowers resembled the hermaphrodite type and one flower was found to have four rudimentary sepals, four petals, four stamens, and one pistil. The stamens were noted to be arranged around the base of the ovary. Each normal anther was observed to have two pollen-producing theca, and each theca was found to have two locules. The number of pollen grains per anther varied between 1380 and 4240 among the genotypes. The pistil was noted to have a deeply hollowed papillate stigmatic surface, and the central part of the style had conducting tissue. The ovarium part of the pistil was found to be surrounded by the nectary tissue, inferior type, and had two atropous ovules. The fruit resembled single-seeded, stone fruit type. This study is the first detailed study on the flower morphology and inflorescences of the cornelian cherry cultivars in Turkey.


2021 ◽  
Vol 7 (3) ◽  
pp. 64-69
Author(s):  
L. Bayramov

Abstract. The zones of distribution of varieties and forms of quince on the territory of the Nakhchivan Autonomous Republic have been established, phenological observations have been carried out, their flowering and fruiting have been studied. On the territory of the Autonomous Republic, flowering of varieties and forms of quince begins in the second decade of April, depending on the distribution zone, with an average daily temperature of 12–13 °C and lasts 12–13 days, depending on weather conditions. Each flower has 10–12 stamens arranged in one row. The article also studied the viability of pollen in a number of quince varieties. Pollen viability was studied in the varieties Sary, Tursh, Ordubad, Gara and wild forms. Pollen fertility was determined by staining with acetocarmine. Pollen germinates in 2–5–10–15 and 20% glucose solution. Counting of germinated pollen grains was carried out under a microscope. The study showed that of all the experimental varieties, the pollen fertility of the Sary quince and Tursh quince varieties is high (up to 96.6–97.1%). The best medium for the germination of quince pollen is a 10–15% glucose solution. Pollen germination in this solution reaches 47.4–88.0%. In distilled water (control), the germination of quince pollen reached from 9.7% to 35.6% for varieties. Quince pollen remains viable for 31–43 days.


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