نتایج جستجو برای: seed banks genetics

تعداد نتایج: 180218  

Journal: :American journal of botany 1998
R Cabin R Mitchell D Marshall

Seed banks are an important component of many plant populations, but few empirical studies have investigated the genetic relationship between soil seeds and surface plants. We compared the genetic structure of soil seeds and surface plants of the desert mustard Lesquerella fendleri within and among five ecologically diverse populations at the Sevilleta National Wildlife Refuge in Central New Me...

2010
R. N. BROWN R. E. BARKER S. E. WARNKE L. D. COOPER L. A. BRILMAN M. A. ROUF MIAN G. JUNG

Lolium perenne L. (perennial ryegrass), and Lolium multiflorum Lam. (annual or Italian ryegrass), differ in several traits related to seed yield. Generally, L. multiflorum spikes are larger than L. perenne spikes, and have more spikelets, more florets per spikelet, larger seeds and awns. The greater number of spikelets and florets and larger seeds are associated with higher seed yield in L. mul...

1996
Luis Marone Manuel E. Horno

It has been suggested that lower rates of granivory in South American warm deserts compared to their North American counterparts arose from a reduction of seed reserves in the former owing to the extinction of argyrolagid marsupials. We measured seed reserves in two habitats of the central Monte Desert in an attempt to detect such seed decline, but to no avail. After moderate rainfall, maximum ...

2005
D. A. Fornara J. W. Dalling

Many tropical pioneer species depend on the presence of highseeddensities inthesoil forsuccessful recruitment following canopy disturbance (Cheke et al. 1979, Dalling & Hubbell 2002, Guevara Sada & Gómez Pompa 1972, Whitmore 1983). However determinants of variation in the composition and abundance of soil seed banks remain poorly understood. Seed bank densities can be affected by rates of seed ...

2017
Cui Li Bo Xiao Qinghai Wang Ruilun Zheng Juying Wu

To provide more insights into the responses of the soil seed bank and vegetation to human disturbance intensity, we selected four land use types, including: native grassland (no human disturbance), abandoned artificial grassland (light human disturbance), artificial grassland (moderate human disturbance), and farmland (severe human disturbance) in a semi-arid climate of northern China. The spec...

Journal: :The New phytologist 2006
William E Finch-Savage Gerhard Leubner-Metzger

Seed dormancy is an innate seed property that defines the environmental conditions in which the seed is able to germinate. It is determined by genetics with a substantial environmental influence which is mediated, at least in part, by the plant hormones abscisic acid and gibberellins. Not only is the dormancy status influenced by the seed maturation environment, it is also continuously changing...

Journal: :Annals of botany 2009
Arne Saatkamp Laurence Affre Thierry Dutoit Peter Poschlod

BACKGROUND AND AIMS Seed survival in the soil contributes to population persistence and community diversity, creating a need for reliable measures of soil seed bank persistence. Several methods estimate soil seed bank persistence, most of which count seedlings emerging from soil samples. Seasonality, depth distribution and presence (or absence) in vegetation are then used to classify a species'...

2004
Arantzazu L. Luzuriaga Adrián Escudero José Miguel Olano Javier Loidi

Our main aim was to determine the contribution of the seed bank to vegetation regeneration following a disturbance consisting in a deep ploughing and a thorough homogenisation of a perennial grassland. In the seed bank prior to disturbance, seed distribution through the vertical soil profile was evaluated to determine the initial seed species structure. Then, several characteristics of the shal...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده کشاورزی 1390

abstract previous researches have shown success of growth hormones usage on flower production increase, pod and prevention of abscission of them in some of the pulses. two tests were done, in order to find out the effects of growth hormones to on flower production increase, pod and chick pea yield composites in farmer conditions (2010-11) and green house conditions as factorial on the proje...

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