玉米果穗生长特征的量纲分析

以两个玉米品种为材料，设置肥密顺、逆境对比试验，应用量纲分析原理筛选反映玉米穗与粒生长特征的变量及其数量关系式，探索量纲分析在玉米花后果穗和穗粒生长特征研究中的应用价值。重量、密度、容(体)积和相对生长率均是果穗和穗粒的重要生长特征。授粉后，果穗密度最小值、最大值分别为0.072和0.56 g/cm3，穗粒密度为0.061和0.63 g/cm3，它们的时间动态均符合y=a+b×cos(ct+d)。果穗密度、穗粒密度、果穗重量相对生长率、穗粒重量相对生长率、果穗体积相对生长率和穗粒容积相对生长率都具有逆境的稳定性，授粉至成熟的均值分别为0.273 g/cm3、0.285 g/cm3、0.10、0.11、0.076和0.076。果穗体积相对生长率和穗粒容积相对生长率具有基因型的稳定性。同一器官的重量相对生长率和容(体)积相对生长率之间关系符合y=ax/(b+x)。量纲分析有助于解析玉米花后果穗和穗粒生长。

Dimension Analysis of Ear Physical Traits During Post-anthesis Growth in Maize

Two maize cultivars were grown in fields under 2 growth condition regimes of plant density by fertilization, and images of whole ear sides and their axial sections were acquired at 7 days intervals throughout kernel filling stages. From these images, ear volumes and bulk volumes of whole ear kernels were extracted using image analysis. Ears were hand shelled and both ears and kernels weighted. Dimension analysis was applied to define growth relevant variables of ears and kernels, and to feature quantitative relations among geometric and gravitic and dynamic traits: weight(W), density(D), volume(V) and relative growth rate(R) for ears(E) and whole ear kernels(K). After silking, ear mass density(ED, similarly hereinafter) ranged from 0.072 to 0.56 g/cm³, and KD from 0.061 to 0.63 g/cm³. They both followed a time function in the form y=a+b×cos(ct+d). None of ED, KD, EWR, EVR and KVR differed between 2 regimes, further, neither of EVR and KVR varied with culitvars. ED, KD, EWR, EVR and KVR post-anthesis until maturity averaged as 0.273 g/cm³, 0.285 g/cm³, 0.10, 0.11, 0.076 and 0.076. WR is a function of VR as the form of y=ax/(b+x) in respect to the same organs studied. Dimension analysis is helpful in understanding growth dynamics of post-anthesis ears and their kernels in maize.