间隔子长度对美丽箬竹克隆分株水分生理整合效应的影响

Effects of Spacer Length on Water Physiological Integration of Indocalamus decorus Ramets under Heterogeneous Water Supply

克隆植物分株间隔子长度(即相邻分株间距离)可能对生理整合产生显著的影响,其抗氧化系统与光合色素的变化可能影响植物对水分异质性的响应能力。该研究以克隆植物美丽箬竹(Indocalamus decorus)为材料,设高[H,(90±5)%]、中[M,(60±5)%]和低[L,(30±5)%]3个基质相对含水率和2个水势梯度(H-L和M-L),测定了3种间隔子长度(10、25和40cm)根状茎相连克隆分株叶片抗氧化酶活性、相对电导率以及丙二醛(MDA)、可溶性蛋白质和光合色素含量,分析美丽箬竹水分生理整合的水分梯度效应、间隔子长度效应与时间效应。结果显示:(1)随处理时间的延长,分株叶片CAT活性、相对电导率及MDA含量均先升高后降低,而叶片SOD活性则与之相反;叶片POD活性和光合色素含量总体上呈"N"型变化,而可溶性蛋白质含量的变化趋势与POD活性呈倒"N"型。(2)水分梯度和间隔子长度均会对美丽箬竹分株间水分生理整合产生影响,随分株间隔子长度增大和水势梯度差减小,低水势受体分株叶片抗氧化酶活性、可溶性蛋白质含量和光合色素含量明显降低,而其相对电导率和丙二醛(MDA)含量明显升高;供体分株水势越高,分株间间隔子越长,供体分株叶片抗氧化酶活性、可溶性蛋白质和光合色素含量越高,而其相对电导率和MDA含量明显降低。研究表明,在异质水分环境下美丽箬竹克隆系统发生了从高水势向低水势分株的水分转移,分株间水势梯度差越大、间隔子长度越短,水分传输的整合强度越高,低水势受体分株获益越明显;随着处理时间的延长,分株间水分生理整合强度在处理前期增强,而在处理后期减弱,反映出供体分株与受体分株间损耗-受益在时间序列上是有变化的,且处理前期损耗-受益表现更为明显。

Spacer length（the distance between connected ramets）may cause significant effects of physiological integration,but lack of correlated studies.The change of antioxidant system and photosynthetic pigment may affect plant response to the moisture heterogeneity,but lack of related research also.The experiment with connected Indocalamus decorus clonal ramets under 3substrate relative water content[high,（90±5）%;intermediate（60±5）%;low（30±5）%]and 2water potential gradient（H-L and M-L）,the antioxidant enzyme,content of soluble protein,MDA and photosynthetic pigment of three spacer length（10,25 and 40cm）connected clonal ramets were determined.The results showed that：（1）CAT activity,leaf relative electric conductivity and MDA content increased at first and then decreased,while SOD activitypresented a trend just on the contrary to the CAT activity with the increasing of treatment time.Overall,POD activity and photosynthetic pigment content present＂N＂type,while soluble protein content showed inverted＂N＂trend with treatment time extended.（2）Water potential gradients and spacer length affected the water physiological integration of Indocalamus decorus clonal ramets.Antioxidant enzyme activities,soluble protein and photosynthetic pigment contents of low water potential receptor ramets decreased,while leaf relative electric conductivity and MDA content increased significantly with the water potential difference increasing and spacer distance shortening between I.decorus ramets.The water potential is higher and the spacer is longer,the antioxidant enzyme activities,soluble protein and photosynthetic pigment contents of donor ramets are higher and the leaf relative electric conductivity and MDA content are lower.All results indicated that water transfer from high water potential ramets to low water potential ramets would be taken place in I.decorus clonal system under heterogeneous water environment.The water potential difference between ramets is bigger,and the length of spacer is shorter,the intensity of physiological integration is stronger,the benefit of receptor ramets is more obvious.Moreover,with treatment time extending,water integration intensity between connected clonal ramets increased in early time,but it weakened later,which reflected that the consumption-benefit effect of donor ramets and receptor ramets changed in time dimension,and the change was much more obvious in early stage of the treatment.The research provided a theoretical reference for artificial water management of commercial bamboo forests.