美丽箬竹水分生理整合的分株比例效应——基于叶片抗氧化系统与光合色素

Divergent ramet ratio affects water physiological integration in Indocalamus decorus:Activity of antioxidant system and photosynthetic pigment content

生理整合是克隆植物实现资源共享,增强对异质生境适应能力的重要手段。其中,水分生理整合是克隆植物最为重要的生理整合,解析竹子水分生理整合特征对于竹林水分科学管理具有重要意义。该研究以分株地下茎相连的美丽箬竹(Indocalamus decorus)盆栽苗为试验材料,设置2个盆栽基质相对含水率(高水势(90%±5%)和低水势(30%±5%))和5个分株比例(1:3、1:2、1:1、2:1、3:1,高水势分株与低水势分株数量比值,地下茎相连的分株总数12株)处理。处理后15、30、45、60天分别取不同处理的克隆分株成熟叶测定抗氧化酶活性、相对电导率和丙二醛含量、可溶性蛋白质含量、光合色素含量,分析基于分株比例的美丽箬竹水分生理整合方向、强度和效率的变化规律。结果表明:在异质水分条件下,美丽箬竹分株间存在着从高水势供体分株向低水势受体分株进行水分转移的生理整合作用,并随着分株比例的增大,整合强度增强,受体分株获益提高,供体分株耗损增大。随着处理时间的延长,处理前期分株间水分生理整合强度增强,处理后期整合强度减弱,反映出供体分株与受体分株间耗-益在时间序列上是有变化的,处理前期耗-益更为明显。研究表明克隆系统分株比例对竹子水分生理整合有重要影响,分株间水分梯度差是水分传导的潜在驱动力,决定水分生理整合方向、强度和效率的是分株间水分供需关系。

Aims Physiological integration of clonal plants allows resources to transport and share among ramets to enhance plant adaptability to a dynamic habitat. Water physiological integration is an important part of physiological inte- gration of clonal plants. Comprehensive understanding of the integration in bamboo is especially important be- cause of the diverse ramet organizations. To provide scientific basis for effective management of water supply for bamboo forests, this study aims to explore the direction and the magnitude of ramet distribution in water physio- logical integration. Methods Our experiment was designed for clonal ramets of Indocalamus decorus with two levels of water con- tent （high water potential at 90%±5% and low water potential at 30%±5%） and five ramet ratios （1：3, 1：2, 1：1, 2：1, 3：1）. Each manipulation was replicated in 12 strains of ramets. We measured the antioxidant enzyme activity, content of soluble protein, malondialdehyde, and photosynthetic pigment. Important findings Water physiological integration existed in L decorus clonal system under different water conditions, allowing water to transfer from high to low water potential ramets. With ramet ratio increase, integra- tion intensity was enhanced, suggesting that the benefit of receptor ramet from the donor ramet increased. Water integration intensity between connected clonal ramets was high in early stage but decreased over time, which re- flected that the consumption-benefit effect of donor and receptor ramets. These results indicated that ramet ratio of clonal system has a major impact on water physiological integration. We conclude that water gradient among the ramets is a potential driving force for water transport. The direction and the magnitude of physiological integra- tion seemed determined by the status of water supply and demand in our intra-clonal system.