scholarly journals Comparative Ontogeny of Hermaphrodite and Pistillate Florets in Helianthus annuus L. (Asteraceae)

2012 ◽  
Vol 4 (2) ◽  
pp. 30-40 ◽  
Author(s):  
Aslıhan ÇETİNBAŞ ◽  
Meral ÜNAL
Keyword(s):  
Helianthus Annuus ◽  
Apical Meristem ◽  
Floral Organ ◽  
Floral Meristem ◽  
Inferior Ovary ◽  
Helianthus Annuus L ◽  
Stamen Primordia ◽  
Flower Organs ◽  
Short Time ◽  
Further Development

The inflorescence of Helianthus annuus L. has two types of flowers (or florets) on a single capitulum; central hermaphrodite disc florets and peripheral pistillate ray florets. In both florets, reproductive development starts with the conversion of apical meristem into floral meristem that will produce floral organ primordia. The only difference between hermaphrodite and pistillate florets in apical meristem stage is that apical meristem of the pistillate florets is not as apparent and curvaceous as apical meristem of the hermaphrodite florets. The differentiation of apical meristem into floral meristem is in the same progress in both florets. In hermaphrodite florets, flower organs; petals, stamens and carpels develop from floral meristem. Differentiation of five petal primordia takes place in the same way in both florets. Firstly filament and then anther differentiates in a stamen. Two carpel primordia appear below the stamen primordia in hermaphrodite florets. In following stages, carpel primordia are lengthened and formed inferior ovary, style, stigma respectively. In pistillate florets, flower organs; petals and carpels develop from floral meristem. They pass directly from the periant initiation to the start of carpel formation. Stamen primordia don’t appear and the further development of carpel primordia stops in a short time, as a result, stigma and style do not exist in pistillate florets. However, an inferior ovary with no ovule forms. In the capitulum of hermaphrodite florets, the development takes place in a centripetal manner; it starts firstly on the outermost whorl, and it proceeds towards inner whorl. However, this is not the case in pistillate florets.

scholarly journals Then There Were Plenty-Ring Meristems Giving Rise to Many Stamen Whorls

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1140
Author(s):  
Doudou Kong ◽  
Annette Becker
Keyword(s):  
Arabidopsis Thaliana ◽  
Dynamic Systems ◽  
Molecular Genetic ◽  
Floral Organ ◽  
Fixed Number ◽  
Floral Meristem ◽  
Ecological Value ◽  
Genetic Studies ◽  
Stamen Primordia ◽  
Floral Meristems

Floral meristems are dynamic systems that generate floral organ primordia at their flanks and, in most species, terminate while giving rise to the gynoecium primordia. However, we find species with floral meristems that generate additional ring meristems repeatedly throughout angiosperm history. Ring meristems produce only stamen primordia, resulting in polystemous flowers (having stamen numbers more than double that of petals or sepals), and act independently of the floral meristem activity. Most of our knowledge on floral meristem regulation is derived from molecular genetic studies of Arabidopsis thaliana, a species with a fixed number of floral organs and, as such of only limited value for understanding ring meristem function, regulation, and ecological value. This review provides an overview of the main molecular players regulating floral meristem activity in A. thaliana and summarizes our knowledge of ring primordia morphology and occurrence in dicots. Our work provides a first step toward understanding the significance and molecular genetics of ring meristem regulation and evolution.

scholarly journals SLGT11 Controls Floral Organ Patterning and Floral Meristem Termination in Tomato

2020 ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa touqeer ◽  
Haiyang Li ◽  
Shuang Wu
Keyword(s):  
Apical Meristem ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
Spatiotemporal Expression ◽  
Meristem Identity ◽  
Higher Temperature ◽  
Type Gene

Abstract Background: Flower development affects fruit production directly in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined.Results: Here, we analyzed a novel tomato mutant in which the normal development of stamens and carpels failed, resulting in ectopic formation of floral and shoot apical meristem in the fourth whorl position, which later developed into stem- and leaf-like structures. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene SLGT11 that encodes a transcription factor belonging to Trihelix gene family. Further RNAi silencing of SLGT11 verified the defective phenotypes of slf mutant. The failed termination of floral meristem and the occurrence of floral reversion in slf mutant indicate that SLGT11 functions as a non-canonical C type gene. Furthermore, we found that the defects in slf were substantially enhanced at higher temperature, with petals transformed into sepals, all stamens disappeared, and increased frequency of ectopic floral meristem.Conclusions: Together with the spatiotemporal expression pattern, we suggest that SLGT11 functions in floral organ patterning and termination of floral meristem identity in tomato.

Mutations of corolla symmetry affect carpel and stamen development in Helianthus annuus

2005 ◽  
Vol 83 (8) ◽  
pp. 1065-1072 ◽  
Author(s):  
Fabio Berti ◽  
Marco Fambrini ◽  
Maurizio Turi ◽  
Daniele Bertini ◽  
Claudio Pugliesi
Keyword(s):  
Genetic Analysis ◽  
Helianthus Annuus ◽  
Recessive Gene ◽  
Floral Organ ◽  
Primary Role ◽  
Drastic Reduction ◽  
Floral Organ Identity ◽  
Stamen Development ◽  
Helianthus Annuus L ◽  
Organ Identity

The inflorescence of sunflower (Helianthus annuus L.) is heterogamous with zygomorphic ray flowers located in the outermost whorl of the head and actinomorphic disk flowers arrayed in arcs radiating from the center of the head. Two mutants with altered corolla symmetry have been described. The Chrysanthemoides (Chry) mutant is characterized by a shift from the polysymmetric corolla of disk flowers into a monosymmetric ray-like corolla. The tubular ray flower (turf) mutant is characterized by a shift from the zygomorphic corolla of ray flowers into a nearly actinomorphic tubular-like corolla. We performed a genetic analysis of turf, showing that a single nuclear recessive gene controls the trait. Furthermore, we characterized in detail the morphological floral features of Chry and turf, demonstrating that both mutations also affect the development of stamens and carpels. Most disk flowers found in the peripheral whorls of Chry heads showed drastic reduction in stamen length, as well as absence of ovules, and developed an unbranched style. By contrast, tubular-like ray flowers of turf achieved the ability to differentiate both fertile stamens and ovules. Homeotic transformations were also identified in the tubular-like ray flowers of turf, affecting both filaments and anthers that displayed petaloid-like traits. Our results point to a primary role for TURF and CHRY in the programming of the corolla symmetry and suggest a key interaction of both genes with floral organ identity genes.Key words: Helianthus annuus, floral symmetry, floral mutants, actinomorphic flowers, zygomorphic flowers.

THE PROBLEM OF SAFE SUNFLOWER (Helianthus annuus L.) USE FOR FOOD AND FODDER PURPOSES (review)

2018 ◽  
Vol 53 (3) ◽  
pp. 485-498
Author(s):  
G.P. Kononenko ◽  
◽  
M.I. Ustyuzhanina ◽  
A.A. Burkin ◽  
◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Helianthus Annuus L

Sunflowers (Helianthus annuus L.) on Top of a Constructed Wetland as an Engineered Ecosystem to Clean Sewage Onsite

2014 ◽  
Vol 2014 (2) ◽  
pp. 83-91
Author(s):  
Alfredo Garcia-Perez ◽  
◽  
Mark Harrison ◽  
Bill Grant ◽  
◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Constructed Wetland ◽  
Helianthus Annuus L
Sign in / Sign up

Export Citation Format

Share Document