• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.187-192
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• 1994

This study was conducted to investigate varietal difference in viviparous germinability at different days after heading and temperature conditions. Three Japonica rice varieties, Sobaekbyeo, Odaebyeo and Hwaseongbyeo, and Sare type rice variety, Jakwangdo, showed higher viviparous germination rate from 20 days after heading, while a Tongil type rice, ]ungwonbyeo, and a Indica varieyt, IR-20, showed still low viviparous germination at 40 days after heading. Viviparous germination rate of rice varieties observed at 4 and 10 days after incubation was greately increased with increasing temperature from 15$^{\circ}C$ to 3$0^{\circ}C$ , and germination rate less than 5% was observed at 4 days after incubating at 15$^{\circ}C$ in all rice varieties teased. Viviparous germination pattern of rice varieties was divided into two types. Three Japonica and Sare type rice varieties showed higher and faster in viviparous germination than a Tongil type and Indica rice verieties. Viviparous germination was delayed under day /night fluctuation of incubation temperature compared with day /night fluctuation of incubation temperature compared with day /night constant condition at the same average temperature. The optimum incubation temperature and duration to evaluate viviparous germinability of rice varieties were 25/15$^{\circ}C$ and 6 days, respectively.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.421-427
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• 2006

To investigate the relationships among the traits related seed dormancy in rice, viviparous germination, dry-heat tolerance and seed longevity were tested using 164 M/G RILs ($F_{17}$) derived from the cross between Milyang 23 (Indica/Japonica) and Gihobyeo (Japonica). At 40 days after heading, the viviparous germination rates of Milyang 23 and Gihobyeo were 0.0 and 7.0%, respectively. The averaged viviparous germination rate of 164 MIG RILs was 3.2%, and their range was from 0.0 to 50.9%. In dry-heat treatment at $90^{\circ}C$ for 24 h followed by the pre-drying at $40^{\circ}C$ for 2 days, Milyang 23 showed higher germinability (98.6%,2.7 days to $T_{50}$) than Gihobyeo (37.6%, 12.9 days to $T_{50}$), and the mean germination rate of 164 M/G RILs was 72.4%. In 54 months after harvest, the germinability in Milyang 23 and Gihobyeo were 90% and 0%, and 71 lines among 164 M/G RILs showed the germinability over 90%. The relationship between seed longevity and dry-heat tolerance was linearly correlated with high positive correlation coefficient. The relationships between seed longevity and viviparous germination, and viviparous germination and dry-heat tolerance were linearly correlated with high negative correlation coefficient. Milyang 23 had higher tolerance against high dry-heat, viviparous germination and long-term storage than Gihobyeo, and 164 M/G RILs showed the medium values of parents.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.283-283
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• 2022

Abiotic stresses such as high/low temperature, drought, salinity, and submergence directly or indirectly influence the physiological status and molecular mechanisms of rice which badly affect yield. Especially, the low temperature causes harmful influences in the overall process of rice growth such as uneven germination and the establishment of seedlings, which has become one of the main limiting factors affecting rice production in the world. It is of great significance to find the candidate genes controlling low-temperature tolerance during seed germination and study their functions for breeding new rice cultivars with immense low-temperature tolerance during seed germination. In this study, 120 lines of Cheongcheong/Nagdong double haploid population were used for quantitative trait locus analysis of low-temperature germinability. The results showed significant difference in germination under low different temperature conditions. In total, 4 QTLs were detected on chromosome 3, 6, and 8. A total of 41 genes were identified from all the 4 QTLs, among them, 25 genes were selected by gene function annotation and further screened through quantitative real time polymerase chain reaction. Based on gene function annotation and level of expression under low-temperature, our study suggested OsGPq3 gene as a candidate gene controlling viviparous germination, ABA and GA signaling under low-temperature. This study will provide a theoretical basis for marker-assisted breeding.