Physiological studies on the stored seeds for some crops

Abstract EN

here is no doubt that the viability of the seeds (the vigour and ability of the seeds to germinate) is one of the necessary factors to obtain a plant density of high production crops.

The viability of the seeds may be adversely affected during storage by environmental factors, causing the loss of the viability of these seeds.

Therefore, loss of seed viability is one of the problems facing agricultural production that has received increasing research attention due to the fact that the information on the causes of loss of seed viability is not yet complete.

Thus, this research aimed at studying the physiological changes during the early germination stage in the seeds stored for some crops under the uncontrolled environmental conditions (heat and moisture; open storage), in an attempt to identify the physiological changes associated with the loss of seed viability during storage.

To achieve this, the seeds of wheat-barley- pearl millet-corn-broad bean were used, which were harvested in different seasons (2017, 2018), as the seeds stored for a period of two and one of years, respectively under ambient conditions.

2019 season seeds, they were used as non-stored seeds for comparison (control).

The results obtained can be summarized as follows: (A) - Seed viability indices.

It was noticed that storing crop seeds used in the study for several different years had a significant effect on seed germination and resulted in a delay in root emergence (germination index) and a decrease in the germination capacity at a decreasing rate with an increase in the length of storage period for all seeds used in the study.

It was found that the indicators of seed quality and vigour decreased with increasing storage time for all seeds used in the research.

(B)- Seedling growth indices.

The results of the fresh and dry weight of both the epicotyl and the root (at the end of the germination period/120 hours) showed an inverse proportion to the length of storage period for all seeds used in the research.

Seed storage led to a significant decrease in the percentage of dry weight loss of germinated seeds (remnants of germinated seeds at the end of the germination period) at a decreasing rate with increasing storage period.

Storage of seeds for several different years resulted in a significant decrease in the length of both the epicotyl and the root (during and at the end of the germination period respectively) at a decreasing rate with the increase in the storage period.

It was also noted that the length of the root was affected to a greater degree relative to the length of the epicotyl.

(C)- Water uptake and solutes leakage.

The stored seeds showed a significant decrease in water uptake, as this diminishing effect increased and was evident by increasing the storage time.

It was found that the degree of electrical conductivity (EC) of the leaked solutes from the seeds is inversely proportional to the vitality of the seeds, as the low vital seeds gave a high electrical conductivity degree and vice versa, and this was observed in all the seeds used in the study.

The increased quantities of leakage with increasing seed life indicate the occurrence of membrane damage that limits the leakage of these solutes from the tissues and thus this leakage leads to weak seedling growth to deplete the metabolites necessary for growth and leakage out of the seeds.

Finally, it is recommended to continue research with regard to chemical changes related to loss of seed viability during open storage, which we could not closely study through this research, due to the role that these changes may play in causing deterioration of seeds during storage and with knowledge of such changes and with the above.

Access to it from physiological changes can, therefore, reach the best way to preserve the viability of the seeds as long as possible.