Chin J Plant Ecol ›› 2025, Vol. 49 ›› Issue (2): 320-330.DOI: 10.17521/cjpe.2023.0158  cstr: 32100.14.cjpe.2023.0158

• Research Articles • Previous Articles     Next Articles

Superior growth process of creeping ramets of Phragmites australis and its physiological mechanisms in an alkaline meadow in Northeast China

HAN Da-Yong1, LI Hai-Yan2, ZHANG Wei1, YANG Yun-Fei1,2,*()   

  1. 1School of Biology and Geography Sciences, Yili Normal University, Yining, Xinjiang 835000, China
    2Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun 130024, China
  • Received:2023-05-31 Accepted:2024-04-09 Online:2025-02-20 Published:2025-02-20
  • Contact: YANG Yun-Fei
  • Supported by:
    National Natural Science Foundation of China(32171682);National Natural Science Foundation of China(31472134)

Abstract:

Aims The reed (Phragmites australis) is a long-rhizomed clonal plant, which is distributed worldwide and has the plasticity and adaptability to change its morphology, even growth form with environmental change. The creeping ramets of reeds are a special growth form generated from their rhizomes extending out of alkaline soil patches. This study aims to explore the growth of creeping ramets and their underlying mechanisms.

Methods Using methods such as regular tracking of ramet growth by hanging tags, measurement of photosynthetic physiology of leaves of different ages, and determination of 15N isotope transfer, we measured and analyzed the growth rhythms and patterns of creeping reed ramets, their photosynthetic characteristics, and indicators of physiological integration between ramets.

Important findings We found that in highly alkaline areas, reeds’ creeping ramets displayed different growth patterns compared to control, upright ramets. After 120 days of growth, the creeping ramets had an average length of (685.25 ± 118.75) cm, and their average growth rate during the observation period was (6.64 ± 3.51) cm·d-1. This was 15.4 times faster than the control, upright ramets, indicating a logarithmic allometry growth process that started quickly but then slowed down. In contrast, the control ramets showed a relatively stable linear isogonic growth process. Young leaves at the top of the creeping ramets had the same maximum photosynthetic capacity as mature functional leaves. The net photosynthetic rate of leaves on the creeping ramets varied in a logistic curve with increasing leaf order, while the control ramets varied in a quadratic curve that first increased and then decreased. Moreover, the theoretical maximum net photosynthetic rate of creeping ramets was 19.4% higher than that of the control ramets. Creeping ramets treated with 15N isotopes had significantly higher levels of 15N abundance in various organs compared to untreated creeping ramets. Creeping ramets are a new adaptive feature of this widespread plant in extremely harsh alkaline habitat patches. The superior growth of creeping ramets is attributed to the high photosynthetic rate of young apical leaves and the physiological integration between tufted basal ramets and creeping ramets. This study provides new insights into the adaptation of reeds to extreme habitats and offers a method for analyzing the superior growth of creeping ramets based on matter production and physiological integration, with important theoretical implications.

Key words: clonal plant, physiological integration, 15N isotope, ramet growth form, assimilate transfer, extreme habitat, plant ecology