Reproductive allocations and resource partitioning mechanisms in plants

研究了两种常绿温带林地半隐芽植物和两种落叶半隐芽植物的叶片各组成器官中几种形态氮(总氮、总可溶性氮、游离氨基酸)、叶绿素含量和光饱和光合作用速率的季节变化。一种多年生球茎植物(Allium Grayi)。两种多年生常绿植物根茎和根部的总氮浓度从冬季到春季呈下降趋势，表明该植物在春季利用了新梢生长。在根茎中，从初夏到越冬，可溶性蛋白质总量逐渐减少，游离氨基酸含量增加。氮素主要以游离氨基酸的形式储存在根部，尤其是在夏季。当年叶中总可溶性蛋白质含量从春季到夏季呈下降趋势，冬季呈上升趋势。…更重要的是，这种季节性变化与先前研究中获得的光饱和光合作用速率的变化是一致的。相反，夏季的叶绿素含量和叶绿素/总氮的比值均高于其他季节。结果表明，氮肥的利用方式较好地利用了夏季较弱的光照和其他季节较高的光照强度。游离氨基酸库的主要成分是整个季节各器官中的天冬酰胺。两种落叶林地多年生植物冬葱各器官氮素组分的季节变化。也与光饱和光合作用速率的变化相一致。总可溶性蛋白质和游离氨基酸的含量在冬季和夏末较高。值得注意的是，谷氨酰胺是冬季这两种林地半隐芽植物鳞茎中的主要游离氨基酸组分之一。精氨酸和天冬酰胺在夏初至夏末以日本鬼针草和黄花蛇舌草最丰富。分别为白桦属和白蜡梅属。并对青葱干物质分配和碳氮经济的季节变化进行了分析。在这种原始多年生植物中发现了最独特的N组分和C/N比的周转模式，这显然反映了该物种生境的非常不稳定和变化的条件。较少

Seasonal changes in several forms of nitrogen (total-N, total soluble-N, free amino acids) in various component organs, chlorophyll content and light-saturated photosynthetic rates of foliage leaves were investigated in two evergreen temperate woodland hemicryptophytes (Pachysandra terminalis and Coptis japonica), two deciduous hemicryptophytes (Allium vistorialis ssp. platyphyllum and Erythronium japonicum), and one bulbous perennial ruderal (Allium grayi). In two evergreen perennials, the concentration of total nitrogen in rhizomes and roots decreased from winter to spring, indicating the plant's utilization of new shoot growth in spring. In the rhizomes, total soluble protein stored by early summer decreased gradually until winter, coupled with an increase in free amino acids. Nitrogen was largely pooled in free amino acids in the roots, especially in summer. The content of total soluble protein in the current-year leaves decreased from spring to summer and then increased in winter. … More This seasonal change was coinncident with the change in light-saturated photosynthetic rates obtained in a previous study. In contrast, chlorophyll content and the ratio of chlorophyll to total nitrogen was higher in summer than in other seasons. The results indicate that nitrogen was used in a manner which better utilizes a very weak light in summer and the relatively high light intensities in other seasons. The major component of the free amino acid pool was asparagine in every organ throughout the season. Seasonal changes in nitrogenous fractions in various organs of two deciduous woodland perennials, Allium victorialis ssp. platyphyllum and Erythronium japonicum, were also coincident with the changes in light-saturated photosynthetic rates. High concentrations of total soluble protein and free amino acids were found in winter and also in late summer. It is also noteworthy that glutamine was one of the major free amino acid fractions in the bulbs of these two woodland hemicryptophytes in winter. On the other hand, arginine and asparagine were richest in early to late summer in E. japonicum and A. victorialis var. platyphyllum, respectively. Seasonal changes in dry matter allocation, and carbon-nitrogen economy of Allium grayi were also critically analyzed. Most unique turnover patterns of N-fractions and C/N ratios were discovered from this ruderal perennial, which obviously reflects a very unstable, changing conditions of the habitats of this species. Less