截根对火炬树克隆片段光合生理参数的影响

THE INFLUNCE OF EUTTING ROOTS TO THE PHOTOSYNTHETIC PHYSIOLOGICAL INDEXES OF Rhus typhina

火炬树(Rhus typhina)是1种典型的木本克隆植物,在华北地区的低山丘陵、农田和道路两旁等通过克隆繁殖形成一定数量的单优群落。截断火炬树母株与克隆分株之间的间隔子是揭示其母株与分株能否独立存活的有效方法之一。为了研究截根对火炬树克隆片段光合生理参数的影响,对样组Ⅰ(由母株,一级分株和二级分株组成的等级系统)和样组Ⅱ(由母株和一级分株组成的等级系统)的火炬树进行了截根前后相对叶绿素含量(SPAD)和光合生理指标的测定,计算了截根前后各项指标相对变化量的大小。结果表明,截根对一级分株的影响最大;对同一样株而言,截根对净光合速率的影响大于对水分利用效率的影响。由此推断,在同一克隆片段内,火炬树的母株与各级分株之间存在克隆整合的关系,且水分整合与光合产物的整合强度不同。

Rhus typhina is a kind of typical woody clone plants,which can establish a certain amount of single dominant community by clonal reproduction on low hills,farmland and both sides of roads in northern China.Cutting spacers between mather plant and ramets of different degrees is one of effective methods to reveal whether they can survive independently.In order to study the influnce of cutting roots to the photosynthetic physiological indexes of Rhus typhina,the relative chlorophyll content（SPAD） and the photosynthetic physiological indexes were measuered respectively before and after cutting roots and the relative variation of indexes were calculated in both groupⅠ（including mother plant,first-degree ramet and second-degree ramet） and groupⅡ（which is composed of mother plant and first-degree ramet）.The results indicated that the influnce of cutting roots to first-degree ramet were the biggest,and that to the same sample tree,the influnce to net photosynthetic rate was bigger than that to water use efficiency.It was concluded that there were clonal integration relationship between mather plant and ramets of different degrees within the same clone sequence and that the integrative intensities of water and photosynthetic products were different.