摘要
利用LI-6400XT便携式光合测定仪对不同水分胁迫的马尾松叶片光合特性进行了测定,进一步研究了马尾松对水分胁迫的适应性。结果表明:(1)在正常(70%～80%)和轻度(50%～60%)水分胁迫下,马尾松净光合速率呈双峰曲线,呈现明显的日变化,这主要受气孔因素限制,前者光合蒸腾速率差异性不显著(P>0.05),后者的差异性明显(P<0.05);在中度(35%～45%)和重度(20%～30%)水分胁迫下,光合蒸腾速率均明显下降,尤其是重度水分胁迫下的两者基本处于稳定状态且非常低。(2)在正常、轻度和中度水分胁迫下,马尾松气孔导度和净光合速率日变化趋势基本一致;在重度胁迫条件下,气孔导度呈现逐渐下降的趋势,但下降趋势不明显。(3)在正常、轻度和中度水分胁迫下,马尾松水分利用效率差异性不明显(P>0.05),轻度和中度水分胁迫下水分利用效率比较高,重度水分胁迫下水分利用效率低于其它3种处理,轻度胁迫下,马尾松水分利用效率效果最好。
The photosynthetic rate of Pinus massoniana Lamb with different water stress was measured by means of Licor-6400, than the adaptability ofP massoniana to water stress was studied. The results indicate that （1） with normal stress （70% - 80%）, mild stress （50%- 60%）, the curves of net photosynthetic rate of P massoniana exhibited two peaks and had an obvious diurnal change because it limited by stomatal factors; the transpiration rate＇s with normal stress was not difference obviously （P 〉 0.05）, that with mild stress was difference obviously （P〈0.05）; with moderate stress （35% - 45%） and severe stress （20% - 30%）, the net photosynthetic rate and transpiration rate were low down significantly, especially, with severe stress, both rates were in a stable state and at a very low level; （2） under the conditions of normal, mild and moderate stress, the diurnal changes of stomatal conductance and net photosynthetic rate of P. massoniana had the same treend; with severe stress, the stomatal conductance declined gradually, and the trend was not obvious. （3） with normal, mild and moderate stress, the differences of water use efficiency ofP massoniana were not obvious（P 〉 0.05）, that with mild and moderate stress were higher; that with severe stress was lower than other three treatments; that with mild stress had a best effect.
出处
《中南林业科技大学学报》
CAS
CSCD
北大核心
2012年第7期58-63,共6页
Journal of Central South University of Forestry & Technology
基金
林业公益性行业科研专项"典型森林植被对水资源形成过程的调控研究"(201104005-01)
关键词
马尾松
光合速率
蒸腾速率
水分利用效率
水分胁迫
Pinus massoniana Lamb
photosynthetic rate
transpiration rate
water use efficiency
water stress
