MORPHOGENESIS OF THE GAMETOPHYTES OF EIGHT MEXICAN SPECIES OF BLECHNUM (BLECHNACEAE)
- A New Hybrid of Serpocaulon (Polypodiaceae) from Costa Rica. Rojas-Alvarado, Alexander Fco.; Chaves-Fallas, José Miguel // American Fern Journal;Jul-Sep2013, Vol. 103 Issue 3, p175
A new hybrid Serpocaulon Ã— sessilipinnum A. Rojas & J.M. Chaves is described. The new taxon has characters intermediate between S. fraxinifolium (Jacq.) A.R. Sm. and S. ptilorhizon (Christ) A.R. Sm., which are related mainly with leaf size, rhizome scales, shape and division of blade, shape...
- megaspore:. Schlegel, Rolf H. J. // Encyclopedic Dictionary of Plant Breeding & Related Subjects;2003, p263
An encyclopedia entry for the term "megaspore," which refers to one of the four cells formed in the ovule of higher plants as a result of meiosis or sexual cell reduction division, is presented.
- megaspore mother cell:. Schlegel, Rolf H. J. // Encyclopedic Dictionary of Plant Breeding & Related Subjects;2003, p263
An encyclopedia entry for the term "megaspore mother cell," which refers to a diploid cell in the ovary that gives rise, through meiosis, to four haploid megaspores, is presented.
- megasporogenesis:. Schlegel, Rolf H. J. // Encyclopedic Dictionary of Plant Breeding & Related Subjects;2003, p263
An encyclopedia entry for the term "megasporogenesis," which refers to the development of the megaspore from the archesporial cell, is presented.
- Cytological and breeding behavior of pentaploids derived from 3x Ã— 4x crosses in potato. Carputo, D. // Theoretical & Applied Genetics;Mar2003, Vol. 106 Issue 5, p883
Cytology and breeding behavior of Solanum commersonii â€“ S. tuberosum hybrids derived from 3x Ã— 4x crosses was examined. The chromosome number of hybrids ranged from hypo-pentaploid (2n=5x â€“ 8=52), to hyper-pentaploid (2n=5x + 7=67), with the euploid pentaploid 2n=5x=60 class...
- heterospory:. Schlegel, Rolf H. J. // Encyclopedic Dictionary of Plant Breeding & Related Subjects;2003, p209
A definition of the term "heterospory" is presented, which refers to the production of spores of two different types of the same plant.
- Pollen-wall Formation in Arum alpinum. ANGER, ELISABETH M.; WEBER, MARTINA // Annals of Botany;Vol. 97 Issue 2, p239
ï¿½ Background and Aims Arum alpinum has a quite uncommon pollen wall. A sporopolleninous ektexine is missing. The outermost pollen wall layer is formed by the endexine which is covered by polysaccharidic ornamentation elements. An ontogenetical investigation was accomplished to clarify...
- spoÂ·ranÂ·giÂ·um. // American Heritage Student Science Dictionary;2009, p322
A definition of the term "sporangium" is presented. It refers to a plant cell or structure in which spores are produced. Ferns, fungi, mosses, and algae release spores from sporangia.
- Identification of microspore-active promoters that allow targeted manipulation of gene expression at early stages of microgametogenesis in Arabidopsis. Honys, David; Sung-Aeong Oh; Reňák, David; Donders, Maarten; Šolcová, Blanka; Johnson, James Andrew; Boudová, Rita; Twell, David // BMC Plant Biology;2006, Vol. 6, p1
Background: The effective functional analysis of male gametophyte development requires new tools enabling the spatially and temporally controlled expression of both marker genes and modified genes of interest. In particular, promoters driving expression at earlier developmental stages including...