Vigor meaning4/16/2023 However, knowledge is limited about the effects of seed filling on starch accumulation and structure during hybrid rice seed production. 17 reported that different morphologies of rice starch were observed during grain filling period and ultimately affected grain quality. 16 found that grain filling affected the formation of resistant starch by comparing three rice mutants with different contents of resistant starch. Moreover, relevant evidence indicates that rice starch formation is influenced by grain development 16, 17. Additionally, starch is deposited in seeds in the form of granules, which are approximately 3–8 μm each and angular in shape in rice seeds 15. Starch is predominantly present in the endosperm cells of mature rice seeds 13, 14. Nevertheless, the variation in seed vigor with different seed filling characteristics has rarely been explored by previous studies. Therefore, seed filling influences seed growth and development and ultimately affects the seed quality of hybrid rice. 12 found that grain quality was affected by grain filling characteristics formed under different temperatures. A high seed filling rate and short seed filling duration limit grain growth and development and contribute to the losses of grain weight and seed yield 7, 8, 9, 10. Previous studies have reported that the grain growth of hybrid rice is associated with certain grain filling characteristics 6, 7. The filling speed of hybrid rice seeds is initially slow, then a rapid filling phase occurs, and then growth slows again with maturity 5. The seed vigor of hybrid rice can be determined by several factors including seed filling, which is characterized by the duration and rate of seed filling 4. In contrast, the hybrid rice seeds with low seed vigor would result in poor crop establishment and lead to great yield losses, suggesting that the seed vigor plays a vital role in the realization of hybrid rice productivity. Vigorous seeds of hybrid rice, which are characterized by a fast germination, high gemination percentage and uniform seedling growth, are beneficial for increasing grain yields and profits for farmers 2. Seed vigor, which refers to the potential of seed to germinate rapidly and uniformly under a wide range of field conditions, is an essential requirement for agricultural production 2, 3. With increasing human populations and decreasing areas of agricultural land, the promotion of rice production, especially hybrid rice production, is essential in China 1. Rice ( Oryza sativa L.) is one of the most important crops in China. In summary, it can be speculated that seed filling characteristics determine hybrid rice seed vigor by affecting starch accumulation and structure. Additionally, when averaged across cultivars, the relative crystallinity and starch granule diameter obtained with a high seed filling rate and short seed filling duration were 3.8% and 15.1% higher, respectively, than those with a low seed filling rate and long seed filling duration. Moreover, a high seed filling rate and short seed filling duration significantly decreased the total starch and amylose contents and increased the amylopectin content. When averaged across cultivars, the seeds with a low seed filling rate and long seed filling duration obsessed 11.9% higher germination percentage (GP) and 22.7% higher vigor index (VI) than those with a high seed filling rate and short seed filling duration. Significant differences in the seed vigor parameters were revealed, with different seed filling characteristics observed under different temperatures. Differences in hybrid rice seed vigor were evaluated in field experiments, conducted across two sites in 20, under different seed filling temperatures along with the underlying mechanisms related to the seed filling characteristics and starch accumulation and structure. In this context, this review article proposes the possibility of using a new measure for vigor and new interpretation of relative vigor, as well as providing the mathematical basis for its use.Seed filling is crucial for seed vigor and starch accumulation and structure. The index reflects the “success” of viable seeds in maintaining their potential under stress. One possible method for correcting such an effect would be to weight vigor by germination, generating an index called relative vigor. Thus, the vigor expressed by the final percentage of normal seedlings tends to underestimate the quality of the batch, considering the total number of seeds. However, the physiological quality within a seed lot is not homogeneous, generating a quality gradient between seeds. Seed vigor is the totality of all properties that determine a rapid and uniform emergence and development of normal seedling under a wide range of conditions. Emergency index in the field, Physiological quality, Stress, Success rate.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |