A new view of water dynamics on germinating diaspores: physiological
perspectives from biophysical measurements
Abstract
We demonstrated that classical biophysical measurements of water
dynamics on germinating diaspores can improve the understanding of the
germination process in a simpler, safer and newer way. This was done
using diaspores of cultivated species as a biological model. To
calculate the water dynamics measurements (weighted mass, initial
diffusion coefficient, velocity and acceleration) we used the mass of
diaspores recorded over germination time. Weighted mass of germinating
diaspores has a similar pattern, independent of the physiological
quality, species or genetic improvement degree. However, initial
diffusion coefficient (related to imbibition per se), velocity and
acceleration (related to the whole germination metabolism) are
influenced by species characters, highlighting the degree of genetic
improvement and physiological quality. Changes in the inflection of
velocity curves demonstrated each phase of germination sensu stricto.
There is no pattern related to the number of these phases, which could
range between three and six. Regression models can demonstrate initial
velocity and velocity increments for each phase, giving an idea of
management of germinative metabolism. Our finds demonstrated that
germination is a polyphasic process with a species-specific pattern, but
still set by the degree of genetic improvement and (or) physiological
quality of diaspores. Among the biophysical measurements, velocity has
the greatest potential to define the germination metabolism