Iranian Journal of Seed Research

The cultivation of sunflower (Helianthus annuus L.) has significantly increased in recent years, mainly due to the quality of its oil, which is useful for the human consumption and industrial purposes. In order to investigate the effect of different seed storage temperatures on seed quality of two sunflower cultivars (Euorfluor and Rcord), seeds were exposed to three storage temperatures (5, 20 and 20-30C°) for four months. Experimental units were arranged factorial manner in a completely randomized design with four replications. The effect of storage under 20C° was more effective in maintaining the vigor of sunflower seeds. The effect of storage at 5C° culminated in damage of vigor of sunflower seeds by increasing electrical conductivity (EC) and mean germination time. The effect of storage at 20-30C° (alternative temperature) brought about seedling growth by comparing with other treatments. This study indicated that best results for germination and vigor of sunflower seeds found for the seed of Euorflour cultivar in comparison with to Record cultivar under seeds storage temperature.

bjective: Cotton seed quality (Gossypium hirsutum L.), as a fundamental input in crop production, is a determining factor in field establishment, final yield, and fiber production. The aim of this study investigates the crucial role of seed morphological characteristics, particularly seed coat thickness and integrity, as a key factor in determining the seed's physiological vigor and its resilience to seed processing.
Method: This study was conducted as a systematic review. To collect information, searches were performed on reputable scientific databases such as ScienceDirect, Scopus, as well as domestic databases such as SID and Magiran, using keywords such as "cottonseed coat," "seed coat thickness," "seed vigor," "cottonseed processing," and their English equivalents. The search was conducted on articles published between the years 2000 and 2024.
Results: The seed coat possesses dual characteristics; its optimal thickness is essential for creating a balance between protection and function. A thicker seed coat provides better protection for the embryo against mechanical damage, safeguards it during the acid delinting process, reduces ion leakage, and plays a fundamental role in greater resistance to pathogens. Furthermore, this type of coat provides a more suitable physical bed for the formation of higher fiber density. Conversely, an excessively thick seed coat can cause physical dormancy and, by creating a mechanical barrier to radicle emergence, lead to delayed and reduced germination rates. On the other hand, seeds with thinner coats, although exhibiting faster water absorption and germination, are highly vulnerable to chemical and mechanical damage, resulting in the production of seeds with low vigor and reduced storability. Harsh seed processing conditions can lead to the formation of micro-cracks in the seed coat, severely compromising its integrity, which directly causes a reduction in germination percentage and seed vigor.
Conclusions: In general, achieving high-quality cotton seeds requires an integrated management approach. This approach includes selecting cultivars with optimal seed coat morphological characteristics, managing environmental stresses during seed filling, and modifying the seed processing procedure to minimize seed damage. Future breeding programs should adopt a dual strategy that simultaneously selects based on beneficial morphological traits and strong physiological performance to develop resilient cultivars that ensure sustainable cotton production.
Highlights

• The cottonseed hull varies among different cultivars.
• The seed hull plays a significant role in achieving seeds with desired vigor.
• In seed processing, the characteristics of the cottonseed hull should be taken into consideration.