Influence of abiotic stresses on different seed traits

05.10.2000 | ESA, Short communication

INFLUENCE OF ABIOTIC STRESSES ON DIFFERENT SEED TRAITS, PLANT DEVELOPMENT AND YIELD FORMATION

Introduction

Seed testing is agriculture (biological) science of evaluating seed quality for agricultural purposes. Seed quality is usually a composite of several factors.

The main emphasis is on influence of different abiotic stresses (drought, low pH, aluminium toxicity, high temperature, low level of macro and micronutrients) on the seed vigour and other characters of seeds of different cultivars of winter wheat and on the progeny generation. Development of expedite methods for analysis of seed vigour of different cultivars of winter wheat is desirable. Analysis of importance of seed vitality in determining response to stresses and analysis of importance of seed vigour for development and yield of different cultivars under field conditions is investigated.

Yield differences among cultivars under abiotic stresses were observed. Statistically significant influence of abiotic stresses on the seed traits, nutrient utilisation and yield stability exists. Resistance of cultivars to different abiotic stresses is desirable for seed quality, yield and yield stability.

Present cultivars expressing higher vigour of seeds, but lower variability in majority of all measured seed traits. Regulation of seed vigour is one of the key issue for developing crop production.

Methods

Responses of wheat cultivars to different combinations of abiotic stresses were analysed in laboratory conditions, climatic chambres and in pot experiments. Field experiments as control and supplementary pot experiments are going on. Plant treatments during experiments were: standard level of nutrients (SN), low level of nutrients (LN), drought (D), drought + low pH (D+pH), high temperature + drought (HT+D), high temperature + drought + low pH (HT+D+pH).

Results

The lowest reduction of 1000 gram weight was observed. Similar situation is at analysis of different embryo traits. Strong influence of stress conditions on grain quality (crude protein content, sedimentatíon test, gluten index) and other traits of seeds (20 traits) was obtained.

In investigated treatments existed the following order of seed morphological and yielding traits decrease (50 traits): HT+D+pH, HT+D, D+pH, D, LN, SN.

There is, however, still a lack of detailed information of changes in anatomy and morphology of roots and their effect on nutrient uptake.

There was also measurable influence of abiotic stresses on a degree of contamination of seeds by spores of pathogenic fungi. Influence of abiotic stresses on the seed nutrient content is also statistically significant.

We can conclude that at different traits of seed vigor, seed morphology and at traits of sprouting plants large influence of different abiotic stresses exist. Chemical and biochemical analysis of seeds of cultivars from different treatments is running. Seed quality has very strong effect on the first phase of plant development and on yield formation. There is possibility to improve traits of seeds by different methods of plant breeding.

Measurements of gross energy and net energy of seeds from different stress treatments in analysed cultivars were made. The statistically significant differences existed only for cultivars, but for stress; treatments were not statistically significant. There were not observed statistically significant results in case of analysis different nutrient level (nitrogen content) influence on gross and net energy.

It is possible to conclude on the basis of analysis of spectrum of storage proteins (by methode PAGE ISTA) that after influence of different abiotic stresses large similarity exists, i.e there is high value of coefficient similarity (strong genetic control). Analysis of other biochemical traits is under preparation (activity of enzymes).

It was also concluded that seed provenance (different abiotic stresses) had very important effect on the value of seeds and the first phases of plant development. From this point of view, testing seeds from different localities and cultivar differences is desirable. There are essential differences already in the juvenile phase (sprouting plants) of development among cultivars in nutrient uptake, content and distribution to the roots and shoots between standard and stress conditions.

There is also possibility of using this phenomenon to select cultivars in the juvenile phase of development with effective nutrient uptake and utilisation at low level of pH.