肥密逆境对玉米果穗高维几何大小的影响及其与产量的关系

INFLUENCE OF NUTRIENTS AND DENSITY STRESS ON EAR HIGH DIMENSIONAL SIZE OF GROWING EAR AND ITS RELATION TO KERNEL YIELD IN CORN

为认识玉米果穗体积等高维几何大小特征的动力学特性,明确肥密逆境对玉米果穗大小特征的影响及其与产量的关系,借助图像处理采集穗长(L)、穗粗(D)、穗正纵截面面积(简称穗面积,S)和穗体积(V),对2个玉米品种在无肥高密条件下以及除叶的效果进行典型变量分析、方差分析及曲线拟合。结果显示,吐丝时玉米果穗体积占其终值的7%、穗面积20%、穗粗36%、穗长58%,吐丝后2周内大小变化剧烈,21d后基本稳定。纵观果穗生长全程,逆境使果穗体积平均降低了24%,穗面积18%、穗粗8%、穗长11%。成熟期穗大小特征与产量的相关系数分别为果穗体积0.96、穗面积0.95、穗粗0.78,穗长0.75。高维与低维大小之间的数量关系为S=0.778*L*D和V=0.515*L*D^2。试验实证和生物物理学分析均表明:玉米果穗体积和穗面积等高维特征对肥密逆境更敏感,而且它们与产量的关系更密切,果穗体积的应用价值更大。

Characterizing dynamics of ear high dimensional size of corn（Zea mays L.）,and understanding the effects of nutrients and density stress on ear size are important in corn crop science.By means of digital image analysis on whole ear RGB images,all 4 ear size traits of volume（V）,longtudinal sectional area（S）,diameter（D） and length（L） were extracted.The field experiment that was carried out on 2 cultivars under 2 fertilizer levels 2 planted density,defoliation treatment in a split plot design.All data were subjected to canonical variate analysis,variance analysis,and curve fitting.Volume was 7% of its final value at silking stage,area 20%,diameter 36%,and length 58%.There were huge changes in ear size within 2 weeks after silking,and after 21d,ear size came to a stable trend.Throughout the ear growth period,growth stress decreased by 24% volume,18% area,8% diameter,and 11% length.Correlation coefficients between ear size traits and kernel yield were 0.96 for volume,area 0.95,diameter 0.78,and length 0.75 at mature stage.Quantitative formula relating area and volume to length and diameter followed as S = 0.778＊ L＊ D and V = 0.515＊ L＊ D^2.Experimental and bio-physical evidences consistently showed that both of volume and area were more sensitive to nutrients and density stress,and had closer relation to kernel yield;volume approved a more potential trait in corn crop science domain.