Relationship of size and shape rice seed to early seedling vigor traits

Abstract

Rice crop improvement program for direct-seeded has been directed at identifying the quality of seeds with rapid uniform germination and biomass accumulation during the initial phase of seedling establishment. Seed and embryo size are thought as two critical factors in the emergence of faster and vigorous seedlings. For the reason, this study was purposed to evaluate the relationship between the size and shape of rice seed with embryo size and its effects on germination. This study was designed using rice seeds from 55 genotypes, which were grouped in three sizes (medium, long, and extra-long) and two shapes (medium and slender). Germination was conducted with the top of paper method in a controlled germinator (24h lighting, 25 ± 2°C, 95%). We have found that the size and shape of seed significantly affected (α < 0.05) to embryo length, the time of radicles and plumules emergence, and seedling dry weight. Longer seeds tended to have longer embryos and emerged of radicles and plumules faster. Meanwhile, longer seeds with slender shape tend to have greater seedling dry weight. The results informed that the size and shape of rice seeds could be considered important characters for early seedling vigor traits in direct-seeded systems.