Chemistry Reference
In-Depth Information
4. Heredity, the availability of a selection at the level of seeds and seedlings
Contemporary knowledge confirm possibility of making selection for the root system and
stress root tolerance on the basis of seedlings stress tolerance, i.e. at time of the sprouting. It
is possible also to evaluate characteristics of seeds and seedlings, i.e. provide selection, after
plant hybridization of the plants on the basis of the seed and seedlings traits for the seed
quality an also for the classic selection in the plant breeding.
Seed of BC
1
progeny of an interspecific cross between a slow germinating
Lycopersicon
esculentum
breeding line (NC84173; maternal and recurrent parent) and a fast germinating
L.
pimpinellifolium
accession (LA722) were evaluated for germination under cold stress, salt
stress and drought stress, and in each treatment the most rapidly germinating seeds (first
2%) were selected [43], .The results confirmed that rapid seed germination under a single
stress environment may result in progeny with improved seed germination under a wide
range of environmental conditions. Seeds of F
2
progeny of a cross between a slow-
germinating (UCT5) and a fast-germinating tomato line (PI120256) were evaluated for
germination under non-stress (control), cold-stress and salt-stress conditions, and in each
treatment the most rapidly (first 5%) germinating seeds were selected, grown to maturity
and self-pollinated to produce F
3
progeny.
In the case of phytohormones content that are genetically controlled by genes and it is not
possible to draw any general conclusion about the correlation between the hormones
content and the germination capacity during sprouting stress tolerance and water uptake.
Why? Because all authors differ in their results and in conclusions; on the other hand it is
possible to read that the fact that the sensitivity of the tissue towards hormones is also a
very important factor in the development of regulation. High temperature stress during
seed filling in controlled environments reduces soybean [
Glycine max
(L.) Merrill] seed
germination and vigor, but the effect of high temperature in the field has not been
determined. Contemporary findings support the results of experiments in controlled
environments by demonstrating that high temperature during seed filling in the field,
without seed infection with
P. longicolla
or physical injury, reduced soybean seed
germination and vigor. Influence of the seed traits on the root system is known; especially
at begin of vegetation period. Quality roots during the growing period are assumption for
the creation of high-quality seed at most crops.
This relationship exists in reverse.
In the
suboptimal conditions, the poor quality of seeds result in reduced growth and performance,
quality and variety of the health of crops. When growth is at the beginning of vegetation
period has the bad quality of embryonic roots according to bad seed quality in the
suboptimal field conditions, the negative consequences are during all the vegetation period
[27, 40, 48, 64, 71, 77, 78].
The root system can be affected by the quality of seeds especially at begin of vegetation
period and change The worse seeds in stress environment can affect not only the quality of
the root system with all the physiological consequences,
but also in some cases at some
characteristics
subsequent generations, especially at the morphologic traits. If the combined
effects of stressors during development and growth of seeds influence the subsequent
