Floral Morphology of Eucalyptus melliodora A. Cunn. ex Schau. And Comparisons With Other Eucalypt Species

1989 ◽  
Vol 37 (2) ◽  
pp. 125 ◽  
Author(s):  
MW Moncur ◽  
DJ Boland
Keyword(s):  
Floral Development ◽  
Floral Morphology ◽  
Pollen Grains ◽  
Scanning Electron Micrographs ◽  
Nectar Secretion ◽  
Flower Opening ◽  
Outer Whorl ◽  
Close Proximity ◽  
Pollen Shed ◽  
Bud Initiation

The important phases of floral development in E. melliodora from bud initiation to anthesis and style abscission are documented by means of scanning electron micrographs. Thirteen phases of bud development from first indication of operculum abscission to style abscission are presented, as well as the timing and duration of each phase. Anther dehiscence commences prior to flower opening and no pollen grains were observed on flowers 2 days after opening. Secondary transportation of pollen after deposition is possible. Nectar secretion did not commence until after pollen was shed and the stigma became receptive. Although individual flowers were protandrous, there was some overlap within a single inflorescence between pollen shed and the 'wet stigma' phase, suggesting that geitonogamy was possible. The style did not increase in length following anthesis, a common feature in Eucalyptus, leaving the stigma in close proximity with the anthers. There was a graduation in filament length from the outer to inner whorls. The innermost anthers produced the most pollen grains while the outermost were staminodal. There was considerable difference between the number of stamens (71-312), staminodes (0-83) and pollen grains per anther (643-1790) found in the six species examined. Stamen length in all species increased across the staminophore from 1.82-6.99 mm in the inner whorl to 4.84-12.61 mm in the outer whorl.

Floral development of Maidenia rubra Rendle, (Hydrocharitaceae)

1983 ◽  
Vol 31 (6) ◽  
pp. 585 ◽  
Author(s):  
CA McConchie
Keyword(s):  
Floral Development ◽  
Floral Morphology ◽  
Male Flower ◽  
Pollen Grains ◽  
Anther Wall ◽  
Male And Female ◽  
The Third ◽  
Male Inflorescence ◽  
Single Flower

Floral development of Maidenia rubra was followed from initiation to maturity. Plants are dioecious. Both male and female inflorescences develop from complexes initiated subapically. Complexes have three meristematic components that include two inflorescence initials flanking a central primordium; these form sequentially in the axil of the preceding initial. The third component also produces an inflorescence and branches sympodially to form further floral initials that have a spiral arrangement. The female inflorescences produce a single flower only with an inferior, unilocular ovary and three sepals, staminodes and bifid stigma. In the locule, numerous bitegmic ovules, borne panetally, are produced. A male inflorescence produces hundreds of small flowers that are released and float to the surface individually. Each male flower has three sepals, a staminode and two stamens, each anther consisting of three locules with eight pollen grains. Prior to maturation, the anther wall breaks down leaving a membraneous layer that assists in binding the octad of pollen grains together. Both male and female inflorescences are enclosed in a pair of fused bracts. The floral morphology is compared with other closely related genera in the Hydrocharitaceae and the unique features are assessed.

scholarly journals Floral Morphology and Development of `Sharpblue' Southern Highbush Blueberry in Louisiana

1997 ◽  
Vol 122 (5) ◽  
pp. 630-633 ◽  
Author(s):  
Y.H. Huang ◽  
C.E. Johnson ◽  
M.D. Sundberg
Keyword(s):  
Floral Development ◽  
Floral Morphology ◽  
Rest Period ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Vaccinium Corymbosum ◽  
Highbush Blueberry ◽  
Cell Embryo ◽  
Growing Conditions ◽  
Southern Highbush

Floral morphology and differentiation of `Sharpblue' southern highbush blueberry (Vaccinium corymbosum L.) were studied under natural growing conditions. There was no rest period during floral development of `Sharpblue' blueberry in Louisiana. Basal florets were already present within a racemic inflorescence in early September. All floral and reproductive organs were clearly visible in early December. Microspores and pollen grains were observed in mid- and late-January, respectively. Megasporocytes, two-cell, four-cell, and seven-cell embryo sacs were found to be simultaneously present in developing ovules in late January, suggesting that megasporogenesis and megagametogenesis in `Sharpblue' blueberry are asynchronous.

Functional dioecy in Gleditsia amorphoides (Fabaceae)

2018 ◽  
Vol 66 (1) ◽  
pp. 85
Author(s):  
María Carolina Cerino ◽  
Damián César Castro ◽  
Geraldina Alicia Richard ◽  
Eliana de Luján Exner ◽  
José Francisco Pensiero
Keyword(s):  
Floral Development ◽  
Floral Morphology ◽  
Pollen Grains ◽  
Industrial Applications ◽  
Pollen Abortion ◽  
The World ◽  
Insect Pollinators ◽  
Unisexual Flowers ◽  
Functional Dioecy ◽  
Woody Shrubs

The genus Gleditsia (Fabaceae) comprises woody shrubs and trees that grow in temperate and subtropical regions around the world. This genus is characterised by sexual polymorphism and functionally unisexual flowers. Gleditsia amorphoides is the southernmost species of the genus, and is widely used as a source of timber and derived products for industrial applications (galactomannans are extracted from its seeds and saponins are derived from its fruits). The species is endemic to the Chaquenean Forest of South America. It is described as morphologically androdioecious, with male and perfect flowers appearing on different plants. In the current study, we characterised floral morphology, experimentally tested the breeding system and analysed flower visitors. Results indicated that G. amorphoides staminate flowers produce viable pollen grains and that perfect flowers have a functional gynoecium and empty anthers, where pollen abortion occurs early in floral development. The species relies on outcrossing, which depends mainly on pollen carried by insect pollinators, to produce seeds and fruits. We conclude that G. amorphoides is functionally dioecious, with staminate and pistillate floral morphs.

scholarly journals Flowering, nectar secretion, pollen shed and insect foraging on Aquilegia vulgaris L. (Ranunculaceae)

2012 ◽  
Vol 65 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Bożena Denisow ◽  
Sebastian Antoń
Keyword(s):  
Reproductive System ◽  
Sugar Yield ◽  
Pollen Production ◽  
Nectar Secretion ◽  
Flower Opening ◽  
Flower Visitors ◽  
Insect Visitation ◽  
Female Phase ◽  
Pollen Shed

This study on blooming biology, nectar secretion, pollen production and insect visitation of <i>Aquilegia vulgaris</i> L. was carried out in 2009 and 2011 in Lublin. The peak of flower opening during the day was between 5.00 and 7.00 (GMT +2). The flowers are protandrous with the female phase beginning approx. on the 3rd day of anthesis. The dynamics of nectar secretion and pollen shed from anthers (progressing from the central part of the androecium outwards) support the reproductive system. The amount of nectar accumulated in the spurs increased from the bud stage and was the highest in the phase with approx. ¾ of dehisced anthers, usually on the 3<sup>rd</sup> day of flower life. Then, towards the end of anthesis, the amount of secreted and accumulated nectar decreased. The number of anthers developed per flower varied from 41 to 61 (mean = 49.1). The mass of pollen per 100 anthers averaged 6.7 mg. Pollen production per flower (mean = 3.28 mg) slightly varied between years and was mainly correlated with the number of developed anthers. Estimated pollen yield was 1.69 g per m<sup>2</sup> and sugar yield 1.22 g per m<sup>2</sup>. Species from the genus <i>Bombus</i> were the main flower visitors, with <i>B. terrestris</i> being the most frequent forager.

Laboratory Exercise on the Segregation of Flower Color and Related Genes Using Salpiglossis sinuata

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 555b-555
Author(s):  
Chiwon W. Lee
Keyword(s):  
Phenotypic Expression ◽  
Pollen Grains ◽  
Flower Color ◽  
Segregation Ratio ◽  
Crop Breeding ◽  
Flower Opening ◽  
Pigmentation Pattern ◽  
Laboratory Exercise ◽  
Demonstration Plant ◽  
Corolla Color

Velvet flower (Salpiglossis sinuata, Solanaceae) can be used as an excellent demonstration plant for horticultural crop breeding classes. Salpiglossis produces large trumpet-like flowers exhibiting an assortment of corolla color and pigmentation pattern. The pistil is large (3 to 4 cm long) with a sticky stigmatal tip and anthers can be easily emasculated prior to anthesis. The large pollen grains are shed in tetrads, which can be separated and individually placed on the stigma. It takes 8 to 9 weeks from seeding to blooming, with a prolific flowering cycle repeated in flushes. Numerous seeds (about 750/capsule) are obtained in 3 weeks after self- or cross-pollination. The influences of three genes that control flower color and pigmentation pattern can be conveniently demonstrated with their dominant and recessive alleles. The R gene controls flower color with red (RR or Rr) being dominant over yellow (rr) flower color. The D gene controls the density of pigmentation with solid (DD or Dd) color being dominant over dilute (dd) color. Corolla color striping is controlled by the St gene with striped (stst) being recessive to non-striped (StSt or Stst) pattern. For example, by using diploid lines of genotypes RRDD (red, solid), RRdd (red, dilute), or rrdd (yellow, dilute) and their crosses, students can easily learn a dominant phenotypic expression in the F1 hybrid and the digenic 9:3:3:1 segregation ratio in the F2 progeny. Another gene (C) that controls flower opening can also be used to show its influence on cleistogamous (closed, self-pollinated, CC or Cc) versus normal chasmogamous (open-pollinated, cc) corolla development. In addition, the induction and use of polyploid (4X, 3X) plants in plant breeding can be effectively demonstrated using this species.

scholarly journals Ethylene and 1-methylcyclopropene action over senescence of nasturtium flowers

2015 ◽  
Vol 33 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Tania P Silva ◽  
Fernando L Finger
Keyword(s):  
Floral Development ◽  
Development Stage ◽  
Flower Senescence ◽  
Premature Senescence ◽  
Flower Opening ◽  
Development Stages ◽  
Post Harvest ◽  
The Third ◽  
Exogenous Ethylene ◽  
Floral Bud

ABSTRACT: This work describes ethylene and 1-methylcyclopropene (1-MCP) action on post-harvest shelf life of four development stages of nasturtium flowers. To reach this goal, we carried out three experiments. In the first and second experiments, we studied five ethylene (0; 0.1; 1; 10; 100 and 1000 μL/L) and three 1-MCP concentrations (0.25; 0.5 and 0.75 μL/L), respectively. In the third experiment, 1-MCP was followed by combined with ethylene (only 1-MCP; only ethylene; and 24 hours of exposure to 0.75 μL/L 1-MCP followed by 24 hours of exposure to 100 μL/L ethylene). All experiments had two control treatments, one keeping non-exposed flowers inside and another outside exposure chambers. Experiments were set in factorial design, in complete blocks at random, with four 10-flower replications each. Flower senescence was determined by a pre-established visual scale and by observing floral bud development. Ethylene dose above 10 μL/L induced flower wilting and premature senescence from the second floral development stage. Furthermore, higher concentrations of exogenous ethylene promoted irregular flower opening and/or morphological abnormalities in opened flowers. 1-MCP effectively extended post-harvest longevity of nasturtium flowers, independent of the concentration and even in the presence of exogenous ethylene.

Ilex calcicola (Aquifoliaceae), a new species from a limestone area of Guangxi, China

Phytotaxa ◽  
2017 ◽  
Vol 326 (4) ◽  
pp. 245
Author(s):  
KEWANG XU ◽  
XIANGGANG SHI ◽  
QIANG FAN ◽  
WEIBIN XU ◽  
WENBO LIAO
Keyword(s):  
New Species ◽  
Electron Micrographs ◽  
Pollen Grains ◽  
Similar Species ◽  
Scanning Electron Micrographs ◽  
A New Species ◽  
Scanning Electron

Ilex calcicola (Aquifoliaceae), a new species from western Guangxi, China, is described, illustrated, and compared to two morphologically similar species: I. mamillata and I. wuana. The scanning electron micrographs of pollen grains and stomata of this new species are also showed in the plate. I. calcicola is currently known only from the limestone hills in western Guangxi.

Floral structure in Thismia (Thismiaceae: Dioscoreales): new insights from anatomy, vasculature and development

2020 ◽  
Author(s):  
Maxim S Nuraliev ◽  
Sophia V Yudina ◽  
Ekaterina A Shepeleva ◽  
Ba Vuong Truong ◽  
Thi Xuyen Do ◽  
...  
Keyword(s):  
Distal Part ◽  
Floral Development ◽  
Floral Morphology ◽  
Reproductive Organs ◽  
Floral Structure ◽  
Interspecific Differences ◽  
Precise Understanding ◽  
Floral Vasculature ◽  
General Appearance ◽  
Comprehensive Study

Abstract Thismia is characterized by an exceptionally complicated floral morphology that is currently not understood properly. In the taxonomic literature, descriptive rather than morphological terms are often applied to parts of the flower in Thismia, relating to the general appearance of the floral organs instead of their precise homologies. Precise understanding of the floral structure is complicated by the rarity of Thismia spp. and the paucity of appropriate material. Here we provide a comprehensive study of reproductive organs of three Thismia spp. (T. annamensis, T. javanica and T. mucronata) including the first investigation of inflorescence architecture and early floral development in Thismiaceae. We found a hitherto unknown diversity of the reproductive shoots in the genus, manifested in the number of floral prophylls (two or three, in contrast to a single prophyll in the vast majority of monocots) and in the branching plane resulting in two distinct inflorescence types, a drepanium and a bostryx. We report the non-acropetal sequence of initiation of floral whorls (with stamens being the last elements to initiate), never previously described in monocots, and the gynoecium composed of completely plicate carpels, also a rare feature for monocots. Floral vasculature is relatively uniform in Thismia, but significant interspecific differences are found in tepal innervation, including the number of tepal traces; some of these differences are not immediately related to the external tepal morphology. We argue that the annulus, which acts as a roof of the hypanthium, possesses an androecium nature and represents congenitally fused bases of stamen filaments. We describe the stamens as laminar structures, which are also shortly tubular in the distal part of the supraconnective with the adaxial tubular side forming a skirt-like appendage. Finally, the placentas, which are column-like when mature, are initially parietal, becoming secondarily similar to free-central placentas through schizogenous separation from the ovary wall.

Assessment of natural interspecific hybridization of blue and Engelmann spruce in southwestern Colorado

1990 ◽  
Vol 68 (7) ◽  
pp. 1489-1496 ◽  
Author(s):  
S. G. Ernst ◽  
J. W. Hanover ◽  
D. E. Keathley
Keyword(s):  
Female Parent ◽  
Isozyme Analysis ◽  
Interspecific Crosses ◽  
Hybrid Inviability ◽  
Engelmann Spruce ◽  
Diallel Mating Design ◽  
Close Proximity ◽  
Gametic Selection ◽  
Total Seed ◽  
Pollen Shed

In a partial diallel mating design among 20 blue and 20 Engelmann spruce parents, the interspecific crosses were successful only with Engelmann spruce as the female parent. No viable seed were obtained from the reciprocal cross among the 60 full-sib families attempted. Under the conditions of artificial pollination and a controlled germination environment, an average of 0.3% of the seed germinated on a total seed basis across all 20 Engelmann spruce females. Many abnormalities were observed among the germinating hybrid seed, suggesting hybrid inviability also contributes to the low crossability between these two species. Isozyme analysis was used to confirm the interspecific hybrids between blue and Engelmann spruce based on the unique genotypic compositions of the hybrids relative to the two species. No natural F1 hybrids between blue and Engelmann spruce were observed in this study based on isozyme analysis of mature individuals or their seedling progeny. Analyses included samples of open-pollinated seed from blue and Engelmann spruce females located in an area where both species are present in close proximity, often side-by-side, and where pollen shed and female strobilus receptivity in the two species are coincident. In addition, there was evidence of possible gametic selection or hybrid inviability among the full-sib progeny based on deviations of observed from expected segregation ratios for progeny isozyme genotypes. Deviations tended to favor the allele more common to both species rather than the allele unique or more common to only one species. Also, the elevationally allopatric blue and Engelmann spruce subpopulations were less divergent genetically than the sympatric subpopulations.

I.—Studies in Floral Morphology. II. The Staminal Zygomorphy of Couroupita guianensis, Aubl.

1922 ◽  
Vol 53 (1) ◽  
pp. 1-15 ◽  
Author(s):  
John M'Lean Thompson
Keyword(s):  
Water Pressure ◽  
Pollen Grains ◽  
Second Phase ◽  
Hydraulic Pressure ◽  
Developmental Study ◽  
Couroupita Guianensis ◽  
Dicotyledonous Plants ◽  
History Of ◽  
Floral Characters ◽  
Pollen Shed

In a former memoir published in these Transactions (20) the developmental study of floral characters has been reopened. It has there been shown that by this study, which for long has received little attention, the investigator, aided by modern technical methods, may gain a fuller understanding of the value of the characters by which his judgment in systematic matters is guided. The subject then dealt with was the initiation of staminal zygomorphy in certain dicotyledonous plants. It was there shown that in the history of a stamen from its initiation as a primordium until its anther is dehisced and its pollen shed there are three more or less distinct consecutive phases. In the first, or phase of initiation, the stamen-primordium is defined. From this primordium an undifferentiated multicellular body arises by rapid cell-division. In the second phase this body undergoes differentiation into the component parts of a stamen ; an anther and frequently a filament and connective are defined, and their cellular construction is completed. In the third and final phase the stamen is extended and functionates forthwith as a disseminator of pollen-grains. In this phase the extensible and elastic walls of the cells of the filament are distended by internal hydraulic pressure, and the anther-walls are dried and finally rupture by inequalities in their rate of shrinkage and by the agency of fibrous devices. These steps form the prelude to the actual functionating of the stamen, and since the final enlargement of the stamen-filament is due to water-pressure, this phase is known as the phase of extension.

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