벼 육성계통의 생리적 질소 이용 효율과 작물학적 특성

Physiological Nitrogen Use Efficiency and Agronomic Characters of Breeding Lines in Rice

This study was carried out to evaluate the variation of physiological nitrogen-use efficiency (PNUE: Grains yield/total nitrogen content of shoot) in rice under different nitrogen (N) fertilizer levels, and to investigate the relationship of PNUE with agronomic characters in order to obtain the basic information for developing high-PNUE lines. A total of 100 F8 recombinant inbred lines (RILs) derived from a cross between Dasanbyeo (tongil type rice, derived from an indica × japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety) were cultivated under ordinary (100 kgN/ha) and low (50 kgN/ha) N-fertilizer conditions in the experimental field. The PNUE of RILs varied from 15.6 to 60.3 in ordinary N-fertilizer condition and from 14.5 to 62.1 in low N-fertilizer condition. The effects of years, N-fertilizer conditions, and their interactions with genotypes in most PNUE-related characters were significant indicating that the characters were highly affected by environments. A significant correlation was found between PNUEs under ordinary N and low N-fertilizer conditions, suggesting that relative PNUE of lines might be stable under different N conditions. PNUE was positively correlated with harvest index and grain yield under both N conditions, while negatively correlated with nitrogen concentration (NC) of grain, NC of straw and straw weight. Path analysis revealed that grain yield is the most positive contributor to PNUE. Taken together, it was likely that high yield and harvest index would be the most appropriate selection criteria for developing high-PNUE lines This study was carried out to evaluate the variation of physiological nitrogen-use efficiency (PNUE: Grains yield/total nitrogen content of shoot) in rice under different nitrogen (N) fertilizer levels, and to investigate the relationship of PNUE with agronomic characters in order to obtain the basic information for developing high-PNUE lines. A total of 100 F8 recombinant inbred lines (RILs) derived from a cross between Dasanbyeo (tongil type rice, derived from an indica × japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety) were cultivated under ordinary (100 kgN/ha) and low (50 kgN/ha) N-fertilizer conditions in the experimental field. The PNUE of RILs varied from 15.6 to 60.3 in ordinary N-fertilizer condition and from 14.5 to 62.1 in low N-fertilizer condition. The effects of years, N-fertilizer conditions, and their interactions with genotypes in most PNUE-related characters were significant indicating that the characters were highly affected by environments. A significant correlation was found between PNUEs under ordinary N and low N-fertilizer conditions, suggesting that relative PNUE of lines might be stable under different N conditions. PNUE was positively correlated with harvest index and grain yield under both N conditions, while negatively correlated with nitrogen concentration (NC) of grain, NC of straw and straw weight. Path analysis revealed that grain yield is the most positive contributor to PNUE. Taken together, it was likely that high yield and harvest index would be the most appropriate selection criteria for developing high-PNUE lines