نتایج جستجو برای: stamens

تعداد نتایج: 557  

Journal: :American journal of botany 1998
W L Crepet K C Nixon

Two taxa of cupulate magnoliid fossil flowers, Cronquistiflora and Detrusandra, are described from the Late Cretaceous (Turonian, ∼90 million years before present [MYBP]) Raritan (or lower Magothy) Formation of New Jersey. The fossil taxa are represented by flowers at various stages of development, associated fragments of cup-shaped floral receptacles with attached anthers, and isolated anthers...

Journal: :Journal of Experimental Botany 2008
Jingqi Xue Yunhui Li Hui Tan Feng Yang Nan Ma Junping Gao

Ethylene production, as well as the expression of ethylene biosynthetic (Rh-ACS1-4 and Rh-ACO1) and receptor (Rh-ETR1-5) genes, was determined in five different floral tissues (sepals, petals, stamens, gynoecia, and receptacles) of cut rose (Rosa hybrida cv. Samantha upon treatment with ethylene or the ethylene inhibitor 1-methylcyclopropene (1-MCP). Ethylene-enhanced ethylene production occurr...

Journal: :Annals of botany 2014
W Scott Armbruster Sarah A Corbet Aidan J M Vey Shu-Juan Liu Shuang-Quan Huang

BACKGROUND AND AIMS Spatial (herkogamy) and temporal (dichogamy) separation of pollen presentation and stigma receptivity have been interpreted as reducing interference between male and female functions in hermaphroditic flowers. However, spatial separation leads to a potential conflict: reduced pollination accuracy, where pollen may be placed in a location on the pollinator different from the ...

Journal: :Forests 2021

Handeliodendron bodinieri has unisexual flowers with aborted stamens in female trees, which can be used to study flower development tree species. To elucidate the molecular mechanism of stamen abortion underlying sex differentiation, stage was determined by semi-thin sections; results showed that occurred 6 during anther development. In addition, differentially expressed transcripts regulating ...

2013
Heng Lian Xiaorong Li Zhongyuan Liu Yuke He

The stamen produces pollen grains for pollination in higher plants. Coordinated development of four microsporangia in the stamen is essential for normal fertility. The roles of miR165/166-directed pathways in the establishment of adaxial-abaxial polarity have been well defined in leaves. However, the molecular mechanism underlying the adaxial-abaxial polarity of the stamen is elusive. Here it i...

Journal: :Annals of botany 2011
Peter K Endress Joseph E Armstrong

Background and Aims Anaxagorea is the phylogenetically basalmost genus in the large tropical Annonaceae (custard apple family) of Magnoliales, but its floral structure is unknown in many respects. The aim of this study is to analyse evolutionarily interesting floral features in comparison with other genera of the Annonaceae and the sister family Eupomatiaceae. Methods Live flowers of Anaxagorea...

Journal: :Annals of botany 2007
Catherine Damerval Sophie Nadot

BACKGROUND AND AIMS Floral symmetry presents two main states in angiosperms, namely polysymmetry and monosymmetry. Monosymmetry is thought to have evolved several times independently from polysymmetry, possibly in co-adaptation with specialized pollinators. Monosymmetry commonly refers to the perianth, even though associated androecium modifications have been reported. The evolution of perianth...

2014
Ido Golan Pia Guadalupe Dominguez Zvia Konrad Doron Shkolnik-Inbar Fernando Carrari Dudy Bar-Zvi Sara Amancio

Tomato ABSCISIC ACID RIPENING 1 (ASR1) was the first cloned plant ASR gene. ASR orthologs were then cloned from a large number of monocot, dicot and gymnosperm plants, where they are mostly involved in response to abiotic (drought and salinity) stress and fruit ripening. The tomato genome encodes five ASR genes: ASR1, 2, 3 and 5 encode low-molecular-weight proteins (ca. 110 amino acid residues ...

2012
Anne K. Greenberg Michael J. Donoghue

The aim of the present study was to infer a substantially larger, more evenly sampled, phylogenetic tree for Caryophyllaceae in order to more confidently resolve relationships within this clade. This would allow us to evaluate previous classification schemes and to infer the evolution of a number of characters that have figured prominently in higher-level taxonomic treatments. We have inferred ...

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