Floral Development in Acacia pycnantha Benth. In Hook

1981 ◽  
Vol 29 (4) ◽  
pp. 385 ◽  
Author(s):  
MS Buttrose ◽  
WJR Grant ◽  
M Sedgley
Keyword(s):  
Light Microscopy ◽  
Pollen Development ◽  
Shoot Growth ◽  
Floral Development ◽  
Developmental Stages ◽  
Early Stage ◽  
Embryo Sac ◽  
Late Winter ◽  
Ovule Development ◽  
Floral Buds

Floral buds of Acacia pycnantha were produced in every month of the year on new shoot growth. The buds produced between November and May developed through to flowering but those produced between June and October aborted at an early stage. Differences in the rate of floral development caused buds produced several months apart to flower in the same month in late winter. Developmental stages from newly produced flower heads to anthesis were studied by light microscopy. Pollen development preceded ovule development and the 16-celled polyads were formed 1 month prior to flowering and before development of the embryo sac.

Comparative floral development reveals novel aspects of structure and diversity of flowers in Cannabaceae

2020 ◽  
Vol 193 (1) ◽  
pp. 64-83 ◽  
Author(s):  
Flávia M Leme ◽  
Jürg Schönenberger ◽  
Yannick M Staedler ◽  
Simone P Teixeira
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Cannabis Sativa ◽  
Glandular Trichomes ◽  
Flower Morphology ◽  
Ovule Development ◽  
3D Reconstructions ◽  
Development Stages ◽  
Broad Base ◽  
Trema Micrantha

Abstract Species of Cannabaceae are wind pollinated, have inconspicuous and reduced flowers that are pistillate, staminate and apparently perfect on the same individual or on different individuals, with a single-whorled perianth and a pseudomonomerous gynoecium. Our objective is to understand the developmental processes that lead to such a reduced flower morphology and polygamy in Cannabis sativa, Celtis iguanaea and Trema micrantha. Floral buds and flowers were processed for surface, histological examinations and 3D reconstructions of vasculature. The single-whorled perianth is interpreted as a calyx because the organs are robust, have a broad base, an acute apex and quincuncial aestivation and are opposite the stamens. Petals are absent from inception. The dicliny is established at different development stages: stamens or carpels are absent from inception (Cannabis sativa), initiated and aborted during early (Trema micrantha, before sporo/gametogenesis) or late (Celtis iguanaea, after sporo/gametogenesis) development. Furthermore, in all species studied the carpels are congenitally united and the pseudomonomerous nature of the gynoecium is confirmed. Glandular trichomes are distributed on the bracts, sepals, anther connective and receptacle. Special floral features shared by species of Cannabaceae include precocious ovule development and sepals that are each vascularized by one bundle. The reduced flowers of Cannabaceae are the result of the absence from inception and/or abortion of organs and even of a whole whorl at different developmental stages, which were probably selected in response to pressures exerted by the similar pollination mechanism.

A technique for the study of floral development

1968 ◽  
Vol 46 (5) ◽  
pp. 720-722 ◽  
Author(s):  
Rolf Sattler
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Three Dimensional ◽  
Serial Sectioning ◽  
Direct Study ◽  
Floral Buds ◽  
Dimensional Picture

When floral buds are studied by serial sectioning, the obtained three-dimensional picture of the buds is a reconstruction which involves some theoretical elements. In contrast to this reconstructive method, the described technique permits the direct study of the three-dimensional developmental stages of flowers. Protoderm cells of floral apices and primordial appendages can be demonstrated.

scholarly journals Accurate staging of reproduction development in Cadenza wheat by non-destructive spike analysis

2020 ◽  
Vol 71 (12) ◽  
pp. 3475-3484 ◽  
Author(s):  
José Fernández-Gómez ◽  
Behzad Talle ◽  
Alison C Tidy ◽  
Zoe A Wilson
Keyword(s):  
Pollen Development ◽  
Floral Development ◽  
Developmental Stages ◽  
Wheat Yield ◽  
Climatic Conditions ◽  
Accurate Staging ◽  
Transgenic Lines ◽  
Reproducible Method ◽  
Spike Analysis ◽  
Non Destructive

Abstract Wheat is one of the most important crops in the world; however, loss of genetic variability and abiotic stress caused by variable climatic conditions threaten future productivity. Reproduction is critical for wheat yield; however, pollen development is amongst the developmental stages most sensitive to stresses such as heat, cold, or drought. A better understanding of how anther and pollen development is regulated is needed to help produce more resilient crops and ensure future yield increases. However, in cereals such as wheat, barley, and rice, flowers form within the developing pseudostem and therefore accurate staging of floral materials is extremely challenging. This makes detailed phenotypic and molecular analysis of floral development very difficult, particularly when limited plant material is available, for example with mutant or transgenic lines. Here we present an accurate approach to overcome this problem, by non-destructive staging of reproduction development in Cadenza, the widely used spring wheat research variety. This uses a double-scale system whereby anther and pollen development can be predicted in relation to spike size and spike position within the pseudostem. This system provides an easy, reproducible method that facilitates accurate sampling and analysis of floral materials, to enable anther and pollen developmental research.

scholarly journals Cornus florida Floral Development

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 860D-860
Author(s):  
K.R. Maluea ◽  
R.W Holton ◽  
S.E. Schlarbaum ◽  
E.T. Graham ◽  
R.N. Triaiano
Keyword(s):  
Light Microscopy ◽  
Floral Development ◽  
Cornus Florida ◽  
Floral Initiation ◽  
Histological Techniques ◽  
Floral Buds ◽  
Terminal Buds ◽  
Landscape Trees

Cornus florida L. floral development was monitored using standard paraffin histological techniques and light microscopy. Terminal buds (putative floral buds) were collected over 6 weeks from mature landscape trees located on The Univ. of Tennessee Agricultural Campus, Knoxville. Examination of samples taken at 3- to 7-day intervals revealed variations in development representing 1- to 2-week differences between florets in a single inflorescence, florets on the same tree and florets from different trees. Floral initiation occurred before July 19th in the 2 years of this study. Floral development followed typical angiosperm stages. Florets, although small, appeared morphologically mature by early September in both years.

Floral development and anatomy of two species of Aechmea (Bromeliaceae, Bromelioideae)

2020 ◽  
Vol 194 (2) ◽  
pp. 221-238
Author(s):  
Sandra Santa-Rosa ◽  
Leonardo M Versieux ◽  
Monica Lanzoni Rossi ◽  
Adriana Pinheiro Martinelli
Keyword(s):  
Light Microscopy ◽  
Reproductive Biology ◽  
Floral Development ◽  
Floral Anatomy ◽  
Floral Buds ◽  
Large Genus ◽  
Electron And Light Microscopy ◽  
Appendage Formation ◽  
Scanning Electron

Abstract Aechmea (Bromeliaceae) is a large genus with controversial systematics and distinct flower shapes and pollinators. We explored floral anatomy and development in two Aechmea spp. belonging to different subgenera to contribute useful information on reproductive biology and taxonomy. We examined floral buds using scanning electron and light microscopy to characterize the development of septal nectaries, petal appendages, ovules, stamens and carpels. In A. gamosepala, we confirmed that the petal appendages develop late, whereas in A. correia-araujoi they develop earlier during floral development. Petal appendage formation included positional changes, possibly affecting floral attributes and visitation by insects, rather than vertebrates. Nectar is released through three basal orifices distally on the ovary, and here we document the link between the nectary region, through discrete canals, upward to the conduplicate lobes of the wet stigma. Improved understanding of the floral development and morphology of Aechmea may help to explain the existence of polymorphic flowers in this genus and may have implications for studies on interactions with pollinators and systematics.

scholarly journals The mac1 Gene: Controlling the Commitment to the Meiotic Pathway in Maize

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1009-1020 ◽  
Author(s):  
William F Sheridan ◽  
Nadezhda A Avalkina ◽  
Ivan I Shamrov ◽  
Tatyana B Batyea ◽  
Inna N Golubovskaya
Keyword(s):  
Female Gametophyte ◽  
Embryo Sac ◽  
Flowering Plants ◽  
Normal Female ◽  
Ovule Development ◽  
Partial Sterility ◽  
Embryo Sac Formation ◽  
Female Gametophyte Development ◽  
Normal Meiosis ◽  
Pleiotropic Mutation

Abstract The switch from the vegetative to the reproductive pathway of development in flowering plants requires the commitment of the subepidermal cells of the ovules and anthers to enter the meiotic pathway. These cells, the hypodermal cells, either directly or indirectly form the archesporial cells that, in turn, differentiate into the megasporocytes and microsporocytes. We have isolated a recessive pleiotropic mutation that we have termed multiple archesporial cells1 (macl) and located it to the short arm of chromosome 10. Its cytological phenotype suggests that this locus plays an important role in the switch of the hypodermal cells from the vegetative to the meiotic (sporogenous) pathway in maize ovules. During normal ovule development in maize, only a single hypodermal cell develops into an archesporial cell and this differentiates into the single megasporocyte. In macl mutant ovules several hypodermal cells develop into archesporial cells, and the resulting megasporocytes undergo a normal meiosis. More than one megaspore survives in the tetrad and more than one embryo sac is formed in each ovule. Ears on mutant plants show partial sterility resulting from abnormalities in megaspore differentiation and embryo sac formation. The sporophytic expression of this gene is therefore also important for normal female gametophyte development.

GAMYB TF modulates bHLH142 and is homeostatically regulated by TDR TF during rice anther tapetal and pollen development

2021 ◽  
Author(s):  
Swee-Suak Ko ◽  
Min-Jeng Li ◽  
Yi-Cheng Ho ◽  
Chun-Ping Yu ◽  
Ting-Ting Yang ◽  
...  
Keyword(s):  
Pollen Development ◽  
Molecular Mechanisms ◽  
Early Stage ◽  
Specific Binding ◽  
Biological Functions ◽  
Altered Expression ◽  
Regulatory Pathways ◽  
E Box ◽  
And Function ◽  
Different Tissues

Abstract GAMYB, UDT1, TIP2/bHLH142, TDR, and EAT1/DTD are important transcription factors (TFs) that play a crucial role during rice pollen development. This study demonstrates that bHLH142 acts downstream of UDT1 and GAMYB and works as a “hub” in these two pollen pathways. We show that GAMYB modulates bHLH142 expression through specific binding to the MYB motif of bHLH142 promoter during early stage of pollen development; while TDR acts as a transcriptional repressor of the GAMYB modulation of bHLH142 by binding to the E-box close to the MYB motif on the promoter. The altered expression of TFs highlights the importance that a tight, precise, and coordinated regulation among these TFs is essential for normal pollen development. Most notably, this study illustrates the regulatory pathways of GAMYB and UDT1 that rely on bHLH142 in a direct and an indirect manner, respectively, and function in different tissues with distinct biological functions during pollen development. This study advances our understanding of the molecular mechanisms of rice pollen development.

scholarly journals Influence of Parenting Styles and Developmental Stages on Identity Formation among Adolescents

2017 ◽  
Vol 4 (3) ◽  
Author(s):  
Ahmad Rezvan ◽  
H. M. Ramakrishne Gowda ◽  
Lancy D’Souza
Keyword(s):  
Identity Formation ◽  
Parenting Styles ◽  
Collective Identity ◽  
Rural Areas ◽  
Developmental Stages ◽  
Early Stage ◽  
Personality Development ◽  
Late Adolescents ◽  
Authoritarian Parenting ◽  
Significant Difference

Paternal attitudes, beliefs and behaviors that appear as family pattern or parenting styles play a key role in personality development and stabilizing the identity of adolescents. The present study assesses parenting styles and identity formation status of adolescents studying in and around Mysore city. A total of 400 adolescents (200 early and 200 late adolescents) were randomly selected covering Mysore city and nearby rural areas, of which equal number among were male and female adolescents and also equal number of them were from urban and rural areas. They were provided with Parental authority questionnaire (PAQ) developed by Buri (1991) and Aspects of Identity Questionnaire – IV (AIQ – IV) developed by Sampson (1978). PAQ measured perceived parenting styles. The AIQ scale measured personal, Relational Social and Collective areas of identity formation. The collected data were, coded and analyzed using SPSS software. The data was analyzed by Two-way ANOVA to find significant difference if any, in the developmental stages, area of living as well as gender of the participants. Results revealed that, adolescents with authoritarian Parenting styles had higher personal identity formation than adolescents with permissive and authoritarian parenting styles. Developmental stage showed significant influence on all components of identity-Personal, Relational, Social and Collective, where in early stage adolescents had higher identity than adolescents at later stage. In general, this study showed that the developmental stages had considerable effect on the collective identity formation in both early and late adolescents.

Sign in / Sign up

Export Citation Format

Share Document