نتایج جستجو برای: pollen grains

تعداد نتایج: 46074  

2005
Cristina Pina Francisco Pinto José A. Feijó Jörg D. Becker

Upon germination, pollen forms a tube that elongates dramatically through female tissues to reach and fertilize ovules. While essential for the life cycle of higher plants, the genetic basis underlying most of the process is not well understood. We previously used a combination of flow cytometry sorting of viable hydrated pollen grains and GeneChip array analysis of onethird of the Arabidopsis ...

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2016
V A D'Ávila E L Aguiar-Menezes V Gonçalves-Esteves C B F Mendonça R N Pereira T M Santos

Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Eleni Katifori Silas Alben Enrique Cerda David R Nelson Jacques Dumais

Upon release from the anther, pollen grains of angiosperm flowers are exposed to a dry environment and dehydrate. To survive this process, pollen grains possess a variety of physiological and structural adaptations. Perhaps the most striking of these adaptations is the ability of the pollen wall to fold onto itself to prevent further desiccation. Roger P. Wodehouse coined the term harmomegathy ...

2002
John M. Jemison Michael E. Vayda

Organic producers, particularly dairy and sweet corn growers, fear losing their organic certification if genetically engineered (GE) proteins are found in their corn (Zea mays L.). Although corn pollen grains are among the largest and heaviest of wind-pollinated plants (Smith, 1990), transport is possible. Corn is a monoecious plant with male and female flowers borne on separate parts of the pl...

Journal: :Environmental Health Perspectives 1981
M J Plewa E D Wagner

We have used three inbreds of Zea mays in our in situ and laboratory studies in environmental mutagenesis. Inbred W22 plants homozygous for wx-C were used in a study to detect the possible mutagenic properties of 32 pesticides or combination of pesticides under modern agricultural conditions. The large numbers of pollen grains analyzed and the ease in detecting mutant pollen grains enabled us t...

Journal: :Journal of economic entomology 2002
J F Esquivel P D Lingren

In previous migration studies, the presence of citrus pollen on adult Helicoverpa zea (Boddie), in conjunction with synoptic weather systems and 72-h backtrack trajectories, were used to identify source zones of migrants. However, data are lacking regarding the retention of citrus pollen for 72-h by H. zea adults. We exposed laboratory-reared and feral H. zea adults to citrus blooms for a 12-h ...

Journal: :Genetics and molecular research : GMR 2010
F Deng S W Zhu L J Wu B J Cheng

The relationship between pollen germination and the dynamic organization of the actin cytoskeleton during pollen germination is a central theme in plant reproductive biology research. Maize (Zea mays) pollen grains were implanted with 30 keV argon ion (Ar(+)) beams at doses ranging from 0.78 x 10(15) to 13 x 10(15) ions/cm(2). The effects of low-energy ion implantation on pollen germination via...

Journal: :Annual review of cell and developmental biology 2002
Elizabeth M Lord Scott D Russell

In flowering plants, pollen grains germinate to form pollen tubes that transport male gametes (sperm cells) to the egg cell in the embryo sac during sexual reproduction. Pollen tube biology is complex, presenting parallels with axon guidance and moving cell systems in animals. Pollen tube cells elongate on an active extracellular matrix in the style, ultimately guided by stylar and embryo sac s...

Journal: :Annals of botany 2004
Ying-Qiang Wang Dian-Xiang Zhang Zhong-Yi Chen

BACKGROUND AND AIMS Pollen grains of 37 species from 11 genera in the family Zingiberaceae were examined to assess qualitatively starch or lipid contents; the pollen grain and ovule numbers per flower and pollen : ovule ratios were also counted and calculated. Pollen : ovule ratios were studied to reveal patterns of variation in the Zingiberaceae. METHODS Freshly open flowers with dehiscing a...

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