Palæozoic Seed Plants
نویسندگان
چکیده
منابع مشابه
Seed Disorders of Forage Plants
rots (Great Plains); seedling blight (Great Plains). Indian ricegrass {Oryzopsis hymenoides) : Seedling blight (far West) ; common root rot and crown rot (far West) ; rhizoctonia rot (scattered) ; snow molds (Pacific Northwest); seed rots (general); root necrosis and crown rots (far West). Kentucky bluegrass {Poa pratensis): Dollar spot (Northeast) ; brown patch (general); foot rot, Helminthosp...
متن کاملThe hydroxyl radical in plants: from seed to seed.
The hydroxyl radical (OH(•)) is the most potent yet short-lived of the reactive oxygen species (ROS) radicals. Just as hydrogen peroxide was once considered to be simply a deleterious by-product of oxidative metabolism but is now acknowledged to have signalling roles in plant cells, so evidence is mounting for the hydroxyl radical as being more than merely an agent of destruction. Its oxidative...
متن کاملPollen and seed dispersal among dispersed plants.
The ecological significance of spacing among plants in contributing to the maintenance of species richness, particularly in tropical forests, has received considerable attention that has largely focussed on distance- and density-dependent seed and seedling mortality. More recently it has become apparent that plant spacing is also relevant to pollination, which often constrains seed production. ...
متن کاملEpigenetic mechanisms governing seed development in plants.
Seed development in flowering plants is initiated by the fusion of two male gametes with two female gametes--the egg cell and the central cell--which leads to the formation of an embryo and an endosperm, respectively. Fertilization-independent seed formation is actively repressed by the FERTILIZATION-INDEPENDENT SEED (FIS) Polycomb group (PcG) proteins, an evolutionarily conserved class of prot...
متن کاملControl of seed size in plants.
R eproductive success in seed plants depends on a healthy seed set. The viability of the embryo is enhanced if a seed contains substantial reserves of starch and protein to nourish the seedling when it germinates months or years later in uncertain conditions. Increased reserves will generally result in an increased seed size, but large seeds are less efficiently dispersed, unless there is human...
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ژورنال
عنوان ژورنال: Nature
سال: 1904
ISSN: 0028-0836,1476-4687
DOI: 10.1038/071068a0