玉米品种耐阴性指标的筛选与评价

采用大田试验，研究了24个玉米品种在50%遮光处理下的形态、生理与产量性状的变化.结果表明：与自然光照相比，遮光处理后，玉米的株高降低，茎粗减小，雌雄间隔期延长，净光合速率减小，比叶重减小，地上部干物质量减少，果穗缩短变细，穗轴直径减小，行粒数减少，籽粒产量显著降低，其中雌雄间隔期、净光合速率、比叶重和行粒数变化的百分率与地上部干物质量和籽粒产量减少的百分率之间呈显著或极显著相关，可作为田间鉴定玉米耐阴性的有效指标.采用综合耐阴性状作为评价参数，经聚类分析表明，郑单958、浚单20、登海602等14个品种属耐阴型品种，安玉12、豫玉22等10个品种属非耐阴型品种.表明以形态、生理指标结合产量性状来评价玉米耐阴性较为客观，且简单易行.

Shade-tolerance indices of maize: Selection and evaluation

A field experiment was conducted to study the morphological, physiological, and yield traits of 24 maize cultivars under 50% shading. Comparing with t
he control, 50% shading decreased the plant height, stem diameter, leaf net photosynthetic rate (P_n), specific leaf weight (SLW), aboveground dry matter accumulation, ear length and diameter, axis diameter, and kernels per row. The interval from anthesis to silking (ASI) was prolonged, and the grain yield was decreased significantly. The percent changes of ASI,P_n,SLW, and kernels per row were significantly correlated with aboveground dry matter accumulation and grain yield, being able to be used as the indices to evaluate the maize shade-tolerance in field. Cluster analysis using comprehensive shade-tolerance traits as evaluation parameters indicated that 14 maize cultivars including Zhengdan 958, Xundan 20, and Denghai 602, etc. were of shade-tolerance type, and 10 cultivars (Anyu 12 and Yuyu 22, etc.) were of shade-sensitive type. It was suggested that adopting the morphological, physiological and yield traits as the indices to evaluate the shade-tolerance of maize would be more objective, simple and practical.