短期环割对骆驼刺气孔导度及叶绿素荧光的影响

为研究骆驼刺对不同环割的生理响应,以塔克拉玛干沙漠南缘策勒绿洲外围骆驼刺为试验材料,设置了对照(CK),韧皮部半割(PS),韧皮部全割(PF),木质部半割(XS)4种处理,研究了骆驼刺的气孔导度、光合色素含量、Chl a/b、叶绿素荧光参数和曲线在不同环割处理下的变化特征。结果表明:短期韧皮部半割对骆驼刺各项生理指标影响不明显;韧皮部全割下,骆驼刺气孔导度、光合色素含量、叶绿素荧光参数有了不同程度的下降;木质部半割显著降低了骆驼刺气孔导度但光合色素含量和大部分荧光参数没有发生变化。处理后第5天和第10天各项参数相差不大,短期内环割对骆驼刺的伤害程度随时间推移变化较小。总体来看,短期环割处理对骆驼刺伤害程度是PFXSPSCK。在荒漠化防治过程中,应尽量避免骆驼刺的韧皮部被全部剥蚀。

Effect of short-term girdling on stomatal conductance and chlorophyll fluorescence in Alhagi sparsifolia

Cele Oasis is located on the southern fringe of the Taklamakan Desert. Due to the influence of northeast wind from Hami to Turpan and northwest wind from the western margin of Taklimakan Desert, Cele Oasis is lack of precipitation and sandstorms in here is very serious. Because of sandstorms attack, Cele county seat have relocated for three times. Cele Oasis is the areas where surfed from sandstorm in the southern edge of Taklimakan Desert most serious. It is also the areas where surfed from sandstorm in china most serious. However, in the periphery of oasis, there is a transition zone vegetation which is constitute by Indigenous plants separate Cele Oasis from Taklamakan Desert. It is this transition zone that protect the normal production and living in oasis. Here, the main constructive species Alhagi sparsifolia not only suffer from the impact of water deficit, high temperature and other stress, but also suffer from Insect grazing and human grazing and other interference. Compared to the stress,the damage to plants caused by the interference tend to be more suddenly, strong, random and destruction. Many woody plants are more willing to allocate photosynthetic products to construct a stress defense system. While most of the herbaceous plant adapt to drastic change of external conditions(such as fire disaster) through rapid growth and reproduction. Generally speaking, in the aspect of ability of anti-interference, herbaceous plant is much stronger than woody plants. While the ability of anti-interference in shrubs whose degree of lignification is moderate is stronger than woody plants and weaker than herbaceous plant. Considering the branches of Alhagi sparsifolia and other shrubs often suffer mechanical damage from insects, hare, sheep and other animals. To research the injury mechanism and recovery capabilities of Alhagi sparsifolia and then to build shrubs protect theory is particularly important.In order to study the effect of physiological parameters in Alhagi sparsifolia under interference. We set four treatments: control(CK), phloem semi-girdling (PS), phloem full- girdling (PF), xylem semi-girdling(XS), and measured stomatal conductance, photosynthetic pigment content, Chl a/b, chlorophyll fluorescence parameters and curve in Alhagi sparsifolia under different girdling treatments. The results show that: except for PI_ABS decreased significantly, the effect of physiological parameters in Alhagi sparsifolia under phloem semi-girdling is not obvious. Under the condition of phloem full girding, stomatal conductance, photosynthetic pigment content, chlorophyll fluorescence parameters of Alhagi sparsifolia have a certain decline. The xylem semi-girdling treatment can significantly reduces the stomatal conductance of Alhagi sparsifolia, while photosynthetic pigments and most of the fluorescence parameters did not change. The physiological parameters under different treatment after five days and ten days did not change a lot. The degree of injury in Alhagi sparsifolia under girdling trestment in a short-term changes little with the time passing. Generally speaking, the degree of injury in Alhagi sparsifolia under girdling trestment is PF > XS > PS > CK. Each physiological conditions of Alhagi sparsifolia under phloem full-girdling is more difficult to recover compared to phloem semi-girdling and xylem semi-girdling. We should try to avoid the phloem of Alhagi sparsifolia be completely denuded in the process of desertification prevention.