Rice (Oryza sativa L.) germplasm with better seedling emergence under direct sowing in flooded paddy field

• Published in: Plant genetic resources: characterization and utilization Vol. 16; no. 4; pp. 352 - 358
• Main Authors: Kashiwagi, Junichi, Hamada, Koji, Jitsuyama, Yutaka
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.08.2018
• Subjects: Cultivars; Cultivation; Emergence; Genotypes; Germplasm; Oryza sativa indica; Parents; Plant breeding; Plant growth; Rice; Rice fields; Screening; Seedlings; Seeds; Soil layers; Studies; Water use; Bangladesh; Madagascar; Japan; India; core collection; hypoxia germination; Oryza sativa L; pot-based screening method
• DOI: 10.1017/S1479262118000011
• ISSN: 1479-2621

Direct sowing of rice in a flooded paddy field is a beneficial cultivation practice for water use and labour efficiency, compared to the transplanted cultivation. However, a drastic reduction in seedling emergence under flooded paddy fields is a serious constraint especially when the seeds fell at deeper soil layers. Suitable rice germplasm for the direct sowing in flooded paddy fields could ensure the success of this cultivation practice. Instead of laborious field-based screening systems, a pot-based screening method was adopted for simplicity and efficient evaluation of seedling emergence of a subset of world rice germplasm (n = 75) at different sowing depths. As a result, two rice genotypes, ‘Vary Futsi’ (landrace from Madagascar, non-glutinous, subspecies Indica) and ‘Dahonggu’ (landrace from China, non-glutinous, subspecies Indica), with consistently better seedling emergence were identified from a wide range of rice germplasm. These genotypes could serve as excellent parents for the breeding program in developing new rice cultivars with the improved seedling emergence in flooded paddy fields. There were no significant differences in the seedling emergence rate in flooded paddy conditions among the groups from various agro-geographical regions.