Germination evolution

Traveset, A. (1998). Effects of seed passage through vertebrate frugivores guts on germination a review. Perspectives in Plant Ecology, Evolution and Systematics 1,151-190. 

ASTM D 6400-04 (homopolymers) >60% of theoretical CO2 evolution after 180 days ASTM D 6400-04 (heteropolymers) >90% of theoretical CO2 evolution after 180 days <10% of the weight of the specimen shall fail to pass through a >2-mm fraction sieve Density, dry solids, volatile solids, salt content, pH, content of elemental N, P, Mg, Ca Rate of germination and biomass >90% of blind value of compost without polymer... 

Nahm, M.H., Kroese, F.G.M., Hoffman, J.W. (1992). The evolution of immune memory and germinal centers. Immunology Today 13,438-441. 

Fox JF (1982) Adaptation of gray squirrel behavior to autumn germination by white oak acorns. Evolution 36 800-809... 

Jensen AR 1998 The factor the science of mental ability. Praeger, Westport, CT Kalisz S 1986 Variable selection on the timing of germination in Collinsia verna (Scrophulariaceae). Evolution 40 479-491... 

Falls et al. (9) and Friedmann et al. (39) pointed out that if a lamella arrives at a germination site prior to the total elapsed time for snap-off, then snap-off is precluded. An upper limit is then placed on the evolution of foam texture. We find in our systems that strong coalescence forces come into play before this upper limit is attained. 

One type of cropping system coupled with one particular property of the herbicides seem to be responsible for the rapid evolution of resistance. Rapid is a relative term it took 8 to 10 generations of selection with both DDT on flies, and atrazine on weeds to evolve resistant populations in the first case this happened in a year, in the second 8-10 years. All cases of resistance appeared in either monoculture where a single herbicide was used, or in rotation where only herbicides with the same site of action were used. In all cases the herbicide had high persistence and thus a high season-long selection pressure that did not allow later germination of weeds. 

Abe H, Uchiyama RM, Sato R, Muto S (1974) Plant growth regulators occurring in marine algae. In Plant growth substances 1973. Hirokawa, Tokyo, pp 201-206 Abeles FB (1966) Auxin stimulation of ethylene evolution. Plant Physiol 41 585-588 Abeles FB (1973) Ethylene in plant biology. Academic Press, London New York Abeles FB, Lonski J (1969) Stimulation of lettuce seed germination by ethylene. Plant Physiol 44 277-280... 

Figure 2. Evolution of palmitic acid (a) and linolenic acid (b) levels in cotyledons of the control line (HAOL-9, ), high palmitic (CAS-5, A) and hi palmitic and oleic mutant (CAS-12, ) during germination. Also shown are the levels in control leaves (O).

Many biochemical reactions can be induced by temperature increase in foods Maillard reactions, vitamin degradation, fat oxidation, denaturation of thermally unstable proteins (resulting in variation of solubility or of the germinating power of grains, for example), enzyme reactions (which can either be promoted or inhibited), and so on. Some of these biochemical reactions generate components suitable, for example, for their sensory properties (flavor development) others may be more or less undesirable for nutritional or potential toxicity reasons (vitamin losses, changes in color, taste or aroma, formation of toxic compounds). All the reactions are linked to the simultaneous evolution of product composition, temperature and water content (or chemical potential, or water activity), these factors varying diflferently from one point to another, from the center to the surface of the products. 

Respiration rate of the yeast cells linearly decreases with water content upon dehydration and apparently stops at hydration level h 0.20 g/g [463] (Fig. 91). For lichens, two switching points in the hydration-induced metabolism were found [464]. Limited metabolism appears when water content is below 10% of the fully hydrated samples, and at hydrations above 20%, another class of enzymes becomes active. Seeds of plants may stay for years in dehydrated state but germinate promptly upon hydration. This makes the analysis of the evolution of physiological activities of seeds with increasing hydration possible. The rate of O2 consumption and the rate of CO2 evolution by dry seeds are very low, indicating an absence of mitochondrial metabolism. It... 

Fig. 1 - NaQ effect on TFA evolution in rape cotyledons during germination in darkness...

We have choosen the 5 day of germination for supplying (l- Q-acetate in the medium because at this stage the enzymes reached their maximum activities [1] The kinetic of incorporation in the total lipid presented practically the same evolution until 12 g/1 (Fig.2). As in the case of previous TFA degradation we noticed an inhibition of lipid biosynthesis at higher NaCl concentrations. 

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