Staminate floral development in Begonia cucullata var. hookeri and three double-flowering begonia cultivars, examples of homeosis

1996 ◽  
Vol 74 (11) ◽  
pp. 1729-1741 ◽  
Author(s):  
Nalda L. Lehmann ◽  
Rolf Sattler
Keyword(s):  
Floral Development ◽  
Staminate Flower ◽  
Double Flower ◽  
Stages Of Development ◽  
Early Stages ◽  
Double Flowering ◽  
Begonia Semperflorens

Homeosis is a process whereby features characteristic of one structure are found in the position that a different structure normally occupies. In three double-flowering begonia cultivars, perianth features are expressed in the positions stamens occupy in a single-flowering begonia. The staminate flower of Begonia cucullata var. hookeri (Willd.) consists of two broad sepals, two small petals in a more or less decussate arrangement, and an androecium of numerous stamens. The staminate flowers of Begonia semperflorens-cultorum ‘Cinderella’, ‘Goldie Locks’, and ‘Lucy Lockett’ also have a perianth of two sepals and two petals, but sepaloid and petaloid appendages form in positions that stamens occupy in the single-flowered progenitor. Using epi-iilumination microscopy, we found that early stages of floral development in the double-flowering cultivars are similar to the early stages of development in the single-flowered begonia, while later stages diverge remarkably. The first primordia that will form petaloid appendages are small and round at the time of initiation, similar in appearance and position to those primordia that become stamens in the single-flowered begonia. As these primordia develop, they broaden and flatten, forming perianth-like appendages. Keywords: homeosis, begonia, double flower, floral development.

Polyaxial development in homeotic flowers of three begonia cultivars

1997 ◽  
Vol 75 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Naida L. Lehmann ◽  
Rolf Sattler
Keyword(s):  
Key Words ◽  
Floral Development ◽  
Staminate Flower ◽  
Floral Buds ◽  
Floral Apex ◽  
Double Flowering ◽  
Begonia Semperflorens

Development of staminate flowers in double-flowering Begonia semperflorens-cultorum cultivars 'Cinderella', 'Goldie Locks', and 'Lucy Lockett' was examined using epi-illumination microscopy, focussing on later stages when secondary partial floral buds formed on the floral apex. This process, switching from floral to inflorescence-like development, is an example of homeosis, the expression of inflorescence features on a floral apex. Floral development began as in a normal begonia flower with the formation of a perianth consisting of two sepals and two petals, but sepaloid and (or) petaloid appendages then developed in what corresponded to stamen positions in normal Begonia species. This was usually followed by lateral elongation, distortion of the primary floral apex, and formation of secondary partial floral buds. The pattern of primordial inception on the secondary apices tended to be irregular, but in some cases, appendage primordia formed in groups of twos, threes, and fours, and in a somewhat alternating formation on the apices. Often, primordial initiation seemed to continue on secondary apices even after anthesis of the staminate flower. Appendage primordia that formed on the secondary buds usually were laterally elongate and bifacial, giving them a phyllomic appearance. Others were, on occasion, more hemispherical at inception, but as they developed they became phyllomic. Key words: homeosis, polyaxial, floral development, intermediate inflorescence.

Developmental morphology of the flower of Anthurium jenmanii: a new element in our understanding of basal Araceae

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Floral Development ◽  
Developmental Morphology ◽  
Calcium Oxalate Crystals ◽  
Stages Of Development ◽  
Early Stages ◽  
Floral Primordia ◽  
Scanning Electron

The early stages of development of the inflorescence of Anthurium jenmanii Engl. were examined using scanning electron microscopy. The inflorescence of A. jenmanii consists of more than 100 flowers arranged in recognizable spirals. Each flower has four broad tepals enclosing four stamens that are not visible prior to anthesis. The gynoecium consists of two carpels. The floral primordia are first initiated on the lower portion of the inflorescence, they then increase in size and appear as transversely extended bulges. The two lateral tepals are the first organs to be initiated, followed shortly thereafter by the two median tepals. The two lateral stamens are initiated first, directly opposite the lateral tepals, and are followed by two median stamens initiated directly opposite the median tepals. A two-lobed stigma is clearly visible during the early stages of development of the gynoecium. On some of the young inflorescences, all floral parts were covered by extracellular calcium oxalate crystals. The release of these prismatic crystals occurs before the stamens and petals have reached maturity. The mode of floral development observed in Anthurium has similarities with that reported for Gymnostachys . However, contrary to Gymnostachys, the development of the flower of A. jenmanii is not unidirectional.

Photoperiod and floral-bud development in Caryopteris × clandonensis

1978 ◽  
Vol 56 (16) ◽  
pp. 1844-1851
Author(s):  
David B. Layzell ◽  
Roger F. Horton
Keyword(s):  
Floral Development ◽  
Anther Wall ◽  
Stages Of Development ◽  
Bud Development ◽  
Early Stages ◽  
Floral Bud ◽  
Short Days

Floral development in Caryopteris × clandonensis A. Simmonds (C. incana (Houtt.) Miq. × C. mongholica Bunge) from cyme initiation through to anthesis is described, with emphasis on the development of the anthers. The later stages of development and anthesis are completed only on mature plants under short days (SD, 8 h light per day). Under long days (LD, 20 h light per day) senescence occurs in the early stages of anther wall differentiation.

NOTEAspects of floral development in Caladium bicolor (Araceae)

2002 ◽  
Vol 80 (8) ◽  
pp. 899-905 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix
Keyword(s):  
Floral Development ◽  
Intermediate Zone ◽  
Intermediate Form ◽  
Sterile Male ◽  
Male Sterile ◽  
Stages Of Development ◽  
Early Stages ◽  
Male Flowers

In the spadix of Caladium, there is a clearly recognizable intermediate zone consisting of sterile male flowers. The transition between the female zone and the male sterile zone is more or less abrupt. During the early stages of development of the inflorescence, a few atypical bisexual flowers between the female zone and the male sterile zone are recognizable. These atypical flowers display a variety of forms. However, in all cases, the staminate portion of the flower is located near the male zone and the gynoecial portion near the female zone. The undeveloped synandroidral portion and the rudimentary gynoecium belong to the same meristematic unit and can be viewed as a single whorl. The early stages of development of atypical bisexual flowers in Caladium and Philodendron are relatively similar and therefore represent an intermediate form between female and male sterile flowers.Key words: inflorescence, homeosis, gradient, flower.

Comparative leaf development of aerial and aquatic growth forms of Myriophyllum aquaticum

Botany ◽  
2013 ◽  
Vol 91 (7) ◽  
pp. 421-430 ◽  
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Epidermal Cells ◽  
The Other ◽  
Developmental Study ◽  
Growth Forms ◽  
Myriophyllum Aquaticum ◽  
Stages Of Development ◽  
Qualitative And Quantitative ◽  
Early Stages ◽  
Other Hand

Myriophyllum aquaticum (Vell.) Verdc. produces two morphologically different forms of leaves based on whether they are aerial or aquatic. The objective of this study was to determine whether there are any similarities or differences between these two growth forms during their early stages of development. A comparative developmental study of aerial and aquatic growth forms of M. aquaticum was conducted from a qualitative and quantitative perspective using a scanning electron microscope. The pattern of leaf and lobe initiation such as their origin and shape were similar in both growth forms until the fourth plastochron (stage P4). Differences between the two growth forms became evident from stage P5 onward, where a larger shoot apical meristem (SAM), elongated epidermal cells, shorter and slightly more numerous lobes, as well as the presence of appendage-like structures characterized aquatic growth forms. On the other hand, aerial growth forms had smaller SAM, bulb-like epidermal cells, and longer and slightly less numerous leaf lobes. Significant differences between growth forms were noted for parameters such as volume of SAM, length of terminal, first, and middle lobes, as well as the length from first to last lobes. The volume of the SAM of aquatic shoot tips was always greater than aerial forms. On the other hand, lobes of aerial forms were always longer than the aquatic counterpart during early stages of development. This study on the development of M. aquaticum shows that the aerial and aquatic growth forms diverge from their early stages of development.

XV. On the development of the parasitic isopoda

1878 ◽  
Vol 169 ◽  
pp. 505-521 ◽  
Keyword(s):  
The Body ◽  
The Other ◽  
Stages Of Development ◽  
Early Stages ◽  
Abdominal Appendages ◽  
Pair Of Antennae

The following paper contains an account of observations on the development of the species Cymothoa œstroides and C . parallela of Milne Edwards; but the forms of the young seem to show that several species are really included under these two names. In the early stages of development the only observable difference that exists between the embryos is one of size, but in the later stages they differ very markedly from each other in their external characters. From adult individuals answering the description of C . œstroides I have obtained four varieties of embryos: two with long antennae and two with short.* In the two former the first pair of antennae are but slightly longer than the head, while the second pair are longer than the body; the eyes are small. In one of the varieties thus characterised the abdominal appendages are fringed with long hairs (fig. 20), and in the other they are smooth.

Morphological variations of Phrosina semilunata Risso, 1822 juveniles (Crustacea: Amphipoda: Hyperiidea), new evidence from the Gulf of Mexico

Zootaxa ◽  
2021 ◽  
Vol 4995 (3) ◽  
pp. 594-600
Author(s):  
MARCO VIOLANTE-HUERTA ◽  
LAURA SANVICENTE-AÑORVE ◽  
MARGARITA HERMOSO-SALAZAR ◽  
AURORA MARRÓN-BECERRA
Keyword(s):  
Gulf Of Mexico ◽  
Monotypic Genus ◽  
Stages Of Development ◽  
Morphological Variations ◽  
Stages Of Growth ◽  
Early Stages ◽  
Southern Gulf Of Mexico ◽  
New Evidence ◽  
Lack Of Knowledge

Lack of knowledge of morphological variations during growth of amphipod crustaceans can result in misidentification of species. In this study, we advance the knowledge of morphological variations of juveniles of the monotypic genus Phrosina Risso, 1822 collected in the oceanic province of the southern Gulf of Mexico. The juveniles differed from the adults mainly in the morphology of pereopods 3 & 4 in that the carpal process is parallel to the propodus, also the rami of the pleopoda consist of only four segments, uropoda 3 are more lanceolate, and the uropoda bear a large prominent spine terminally. These morphological variations have not been described for the species previously. Therefore, the current observations enrich the description of P. semilunata in the early stages of growth and support the need for further taxonomical studiest that could help identify species at different stages of development.  

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