Abstract
This study was conducted to characterize and to elucidate the inheritance mode of green-kerneled rices which were selected in rice germplasms collected in China. Three green-kerneled varieties (Hexi 41, Beijingluimi-1, and Jilinluimi-1), three regular white varieties (Ilpumbyeo, Dasanbyeo, and Hwacheong wx sgr) and 11 hybrid populations crossed between them were used. To investigate the environmental variation, plant materials were grown under two levels of nitrogen-fertilizer and under different ripening temperatures. The green-kerneled rices maintained green color in pericarp even after physiological maturity stage because the chlorophyll was faded away slowly. Hexi 41 showed the highest green color among green-kerneled germplasms, and followed by Beijingluimi-1. The greenness of dehulled rices of Hexi 41, Beijingluimi-1 and Ilpumbyeo were not significantly affected by different nitrogen-fertilizer levels. High temperature during ripening significantly decreased the greenness of brown rices of Hexi 41, Beijingluimi-1 and Ilpumbyeo. The greenness of brown rices was found to be inherited in a quantitative fashion implying that polygenes were involved. The broad-sense heritabilities ranged from 0.51 to 0.92, suggesting that selection for greenness in early generations might be feasible. However, there was a strong correlation between the greenness and days to heading, indicating that the greenness was largely affected by air temperature during ripening as well as by the genotype. The strategy for breeding green-kerneled rice varieties in relation to heading date was discussed.