Key message

This is a descriptive study on leaf ontogeny, showing the main morphological and physiological changes during development of leaves from young plants in three Eucalyptus genotypes.

Abstract

A descriptive study on key morphological and physiological features during leaf ontogeny in three genotypes—AEC 144, CO 1407 and VCC 865—of Eucalyptus young plants was performed. The work was developed under partially controlled environment, at two stages. First, daily photographing was used aiming at chronologically documenting noticeable changes in leaf ontogeny, such as size, shape and color, to define the reference stages of complete leaf development. Then, a time-varied split plot experiment was carried out to evaluate morphological and physiological changes in genotypes × leaf development stages relationship. The time required for complete leaf formation in Eucalyptus young plants varied at 44–49 days. Throughout this period, changes in leaf size, shape and color allowed us to establish four development stages, hereinafter referred to as A, B, C and D. Morphological features and color looks were described in detail at each leaf development stage. Physiological features, such as dry mass, leaf area, photosynthetic pigment content and photosynthesis rates, were increased throughout leaf development. At the early development stages, the mean values of these features were similar, by comparing the genotypes, but from stage C, however, they became larger in AEC 144 genotype than in CO 1407, which in turn were larger than in VCC 865. Decrease in sucrose hydrolysis by invertases and increase in reducing and soluble sugar content were also found during leaf ontogeny. These biochemical and metabolic changes can be interpreted as evidences of sink-to-source leaf transition, which was consolidated from stage C.

中文翻译：

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基因型桉树幼叶叶片发育过程中的形态和生理变化

关键信息

这是对叶片个体发育的描述性研究，显示了三种桉树基因型的年轻植物叶片发育过程中的主要形态和生理变化。

抽象

对桉树幼苗的三种基因型（AEC 144，CO 1407和VCC 865）的叶片发育过程中的关键形态和生理特征进行了描述性研究。该工作是在部分受控的环境下分两个阶段开发的。首先，使用每日摄影的目的是按时间顺序记录叶片个体发育的明显变化，例如大小，形状和颜色，以定义完整叶片发育的参考阶段。然后，进行了随时间变化的分割图实验，以评估基因型×叶片发育阶段关系的形态和生理变化。桉树完整叶片形成所需的时间幼小植物在44-49天变化。在此期间，叶片大小，形状和颜色的变化使我们能够建立四个发育阶段，以下分别称为A，B，C和D。在每个叶片发育阶段均详细描述了形态特征和颜色外观。在整个叶片发育过程中，生理特征（如干重，叶面积，光合色素含量和光合速率）均增加。在开发的早期阶段，通过比较基因型，这些特征的平均值相似，但从C期开始，AEC 144基因型的特征值大于CO 1407的特征值，而CO 1407的特征值又大于VCC 865的特征值。蔗糖在蔗糖中被转化酶水解，在叶片发育过程中还发现还原糖和可溶性糖含量增加。