نتایج جستجو برای: seed banks genetics

تعداد نتایج: 180218  

2013
Magda I. Soliman

Seed morphs of Calendula officinalis were investigated in order to examine the genetic variability which correlates with seed polymorphism and its impact on collection strategy of gene banks. The basic parameters to get the evidence were obtained from morphological data, karyotype analysis, electrophoretic pattern of seed proteins as well as nucleic acid analysis. Seven seed morphs were observe...

2001
Ingemar Kaj Stephen M. Krone Martin Lascoux

We study the genealogical structure of samples from a population for which any given generation is made up of direct descendents from several previous generations. These occur in nature when there are seed banks or egg banks allowing an individual to leave offspring several generations in the future. We show how this temporal structure in the reproduction mechanism causes a decrease in the coal...

Journal: :Current Biology 2007
Rob Kesseler Wolfgang Stuppy

Humans are well used to appreciating the beauty of flowers, and breeding them to heighten their attractions but we remain largely ignorant of their seeds, something that can also be of stunning beauty, although often on an microscopic scale. A new book, Seeds: Time Capsules of Life, hopes to help redress this perception and raise awareness of conservation issues at a time of unprecedented press...

Journal: :The American naturalist 2007
C J Clark J R Poulsen D J Levey C W Osenberg

We examine the relative importance of processes that underlie plant population abundance and distribution. Two opposing views dominate the field. One posits that the ability to establish at a site is determined by the availability of suitable microsites (establishment limitation), while the second asserts that recruitment is limited by the availability of seeds (seed limitation). An underlying ...

Journal: :علوم گیاهان زراعی ایران 0
حمیدرضا عیسوند استادیار گروه زراعت و اصلاح نباتات دانشکدۀ کشاورزی دانشگاه لرستان

one of the most common methods for conservation of plant genetic resources is their ex situ storage as seed gene banks. seeds that are stored in the gene banks must be regenerated due to exchange and seed deterioration; if they not be regenerated the potential benefits of infrastructure investments for germplasm ex situ conservation may not be attained. prediction of seed longevity is based on ...

2000

The seed bank in the soil and litter of an annual grassland in the upper salt marsh of the Guadalquivir delta (SW Spain) contained on average 49 110 seeds/m2; 29 species were represented. Field censuses of the grassland, in two consecutive springs, yielded 7 410 and 9 520 plants/m2 respectively. A combined Correspondence Analysis of the seed bank samples and field censuses showed differences in...

2000
Sara Leckie Mark Vellend Graham Bell Marcia J. Waterway Martin J. Lechowicz

We assessed the size and composition of the seed bank in 31 plots representing a range of habitats within an old-growth, temperate deciduous forest at Mont St. Hilaire, Québec, Canada. We identified 49 taxa in the seed bank, with an average of 40 species·m–2 and a median density of 1218 seeds·m–2. The most frequent seeds were species of Carex and Rubus, Diervilla lonicera, and Eupatorium rugosu...

2014

Seed longevity, a fundamental plant trait for ex situ conservation and persistence in the soil of many species, varies across populations and generations that experience different climates. Mondoni et al. (pp. 1257–1263) study seeds from alpine and lowland populations of Silene vulgaris and show that seed longevity has a genetic basis but may show strong adaptive responses, which are associated...

Journal: :Annals of botany 2007
Julie Beckstead Susan E Meyer Cherrilyn J Molder Caitlyn Smith

BACKGROUND AND AIMS Pathogen-seed interactions may involve a race for seed resources, so that seeds that germinate more quickly, mobilizing reserves, will be more likely to escape seed death than slow-germinating seeds. This race-for-survival hypothesis was tested for the North American seed pathogen Pyrenophora semeniperda on seeds of the annual grass Bromus tectorum, an invasive plant in Nort...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید