不同氮效率玉米杂交种的叶光反射研究

LEAF REFLECTANCE OF MAIZE HYBRIDS DIFFERING IN NITROGEN EFFICIENCY

培育氮高效的玉米新品种是众多植物育种项目的主要研究领域。反射测量可能用于对作物的氮效率进行快速而经济的评估。本研究以适应低氮的SL (氮高效品种 )和适应高氮的TH (对照品种 )两个玉米杂交种为材料 ,设 0和 1 5 0kgN hm2 两个施氮水平。在播种后 46、62、76、90和 1 0 4d ,用数码相机LEICASIPRO测量玉米叶片的光反射 ,测量结果用L a b 颜色系统进行评估和分析。在这个三维颜色系统中 ,反射参数a 和b 分别描述绿 红和蓝 黄颜色的比例 ,参数L 用来描述颜色的浅淡。结果表明 ,在低氮条件下 ,开花期前后的玉米叶片光反射参数a 和b 在 5 1 0～ 780nm、5 1 6～ 780nm、和 5 4 0～ 780nm 3个特定波段表现出规律性的变化 ,SL 的反射参数a 显著高于TH 的 ,反射参数b 正相反 ,显著低于TH 的b 值。上述结果说明 ,开花期前后的反射测量可以作为玉米氮效率筛选的一个简单、快速而经济的评估工具。

The development of new maize variety with improved nitrogen effciency is a major thrust in many plant-breeding programs. A field experiment was conducted with two maize hybrids, SL *(adapted to low nitrogen condition) and TH *(adapted to high nitrogen condition). The low and high nitrogen levels were designed as 0 kg N/hm 2 and 150 kg N/hm 2, respectively. Leaf scans of maize plants were performed with a digital LEICA S1 PRO camera under controlled light conditions at 46,62,76,90 and 104 days after sowing. Leaf scans were evaluated with the L *a *b *-color system. This is a three-dimensional system with parameter a * describing the green/red percentage and parameter b * the blue/yellow percentage of a color. L * represents the lightness of a color. The results showed that reflectance parameter a * and b * of leaves at around flowering in 510～780nm, 516～780nm and 540～780nm wavelength ranges changed regularly between SL * and TH * under low nitrogen condition. The parameter a * of hybrid SL * is higher than that of hybrid TH * and parameter b * of hybrid SL * is lower than that of hybrid TH *. The results indicate that reflectance measurements may provide a simple, fast and inexpensive tool for the screening of nitrogen use effciency of different maize genotypes.