关键词: 活动节律, 无性系植物, 养分消耗, 养分积累, 器官衰老, 分株龄级, 可溶性碳水化合物, 种群生态学

Abstract: Aims Aging is an important stage in the life cycle of plants, and the nutrient storage capacity and activity of different organs in plants are important criteria for judging individual aging. To date, the changes in the storage capacity and activity of storage organs during the aging process of different age class ramets of clonal plants remain unclear. Methods Aster pekinensis is a root sucker form clonal plant. In the Northeast grassland, the ramets are mainly composed of three age classes. In this study, the differences of water soluble carbohydrates (WSC) contents among storage organs (stem base, root collar and taproot) and age classes, and the seasonal variation rhythm in the 1-3 years old ramets of Aster pekinensis population were analyzed quantitatively. Important findings In the yellow leaves stage, the WSC content of the taproot was higher than that of the root collar in the Aster pekinensis population. The WSC content of root collar and taproot of 1 a and 2 a ramets was significantly higher than that of 3 a ramets. The WSC content of stem base was significantly lower in the 1 a ramets than in the 2 a and 3 a ramets. Throughout the entire growth season, the root collars of the 1 a ramets in Aster pekinensis population always received priority allocation of nutrients, and their WSC content continued to accumulate in an exponential form. The nutrient contents in the root collars of the 2 a and 3a ramets, as well as the taproots of the three age class ramets, were all consumed first and then accumulated, and the WSC content changed in the form of a quadratic curve. The nutrient storage capacity of the taproot was generally greater than that of the root collar, whereas the activity of the root collar was greater than that of the taproot in the three age class ramets in Aster pekinensis population. The nutrient storage capacity and activity of young-aged ramets were the strongest. There were no signs of aging in adolescent-aged ramets. The old-aged ramets were significantly aging, and their nutrient storage capacity and activity reduced significantly. This study provides a new approach that combines qualitative and quantitative analysis to understand the relationship between the spatio-temporal changes of WSC content and the aging process of individual in plant populations. Methods Aster pekinensis is a root sucker form clonal plant. In the Northeast grassland, the ramets are mainly composed of three age classes. were sampled. The differences of WSC contents among storage organs (stem base, root collar and taproot) and age classes, and the seasonal variation rhythm in the 1-3 years old ramets of Aster pekinensis population were analyzed quantitatively. Important findings In the yellow leaves stage, the WSC content of the taproot was higher than that of the root collar in the Aster pekinensis population. The WSC content of root collar and taproot of 1a and 2a ramets was significantly higher than that of 3a ramets (p < 0.05). The WSC content of stem base was significantly lower in the 1a ramets than in the 2a and 3a ramets. Throughout the entire growth season, the root collars of the 1a ramets always received priority allocation of nutrients, and their WSC content continued to accumulate in an exponential form. The nutrient contents in the root collars of the 2a and 3a ramets, as well as the taproots of the three age classes ramets, were all consumed first and then accumulated, and the WSC content changed in the form of a quadratic curve. The nutrient storage capacity of the taproot was generally greater than that of the root collar, whereas the activity of the root collar was greater than that of the taproot in the three age class ramets in Aster pekinensis population. The nutrient storage capacity and activity of young-aged ramets were the strongest. There were no signs of aging in adolescent-aged ramets. The old-aged ramets were significantly aging, and their nutrient storage capacity and activity reduced significantly. This study provides a new approach that combines qualitative and quantitative analysis to understand the relationship between the spatio-temporal changes of WSC content and the aging process of individual in plant populations.

Key words: activity rhythmic, clonal plant, nutrient consumption, nutrient accumulation, organic aging, ramet age, water-soluble carbohydrate, population ecology