摘要
通过盆栽和持续干旱研究了干旱胁迫(以2 d为一个处理间隔,持续干旱0-16 d)对香樟(Cinnamomum camphora)幼树生长及光合特性的影响.结果显示:(1)干旱胁迫下香樟幼树的地径、树高生长量受到了抑制.轻度、中度干旱处理(干旱时间2-8 d)叶片含水量和叶片相对含水量与对照差异均不显著,重度干旱处理(干旱时间>10 d)下显著低于对照(P<0.01);(2)干旱胁迫影响了香樟叶片光合作用的日变化进程,妨碍了其有机物质积累;(3)干旱胁迫下香樟叶片光合色素总量先升高后降低,在干旱第8天达到最高.所有干旱处理的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均受到不同程度的抑制.气孔因素和非气孔因素共同作用影响香樟幼树的光合作用,在干旱初期(干旱时间2-8 d)气孔因素起主导作用,干旱后期(干旱时间>10 d)非气孔因素起主导作用;(4)干旱胁迫下香樟幼树叶片的表观量子效率(AQY)、RuBP羧化速率(CE)、光补偿点(LCP)、光饱和点(LSP)及CO2补偿点(CCP)均显著降低,表明干旱会降低香樟幼树对环境中光照和CO2的利用及适应能力.综上,干旱胁迫下香樟幼树的水分生理状况变差,光合能力及光合日变化进程受到影响,对环境中光照和CO2的利用及适应能力也明显降低,最终香樟幼树的形态生长受到抑制.
Cinnamomum camphora is a broad-spectrum tree species wildly distributed in south China. However, the effects of drought stress on growth and photosynthesis of C. camphora are poorly understood. This paper aimed to study the response of young C. camphora trees to drought stress to provide theoretical reference for water management of C. camphora plantations. The experiment was conducted in greenhouse in Aug. 2013. Twenty-nine pots（27 cm in diameter and 25 cm in height） of C. camphora were treated with drought stress for continuously 0 d, 2 d … 16 d with a time interval of 2 d, respectively. After 16 d treatment, morphological traits of C. camphora saplings, diurnal variation of photosynthetic rate, light responses, CO2 responses, and some other biochemical parameters were determined. The results showed inhibited diameter increment（Zd） and height increment（Zh） under drought stress. Leaf water content（LWC） and leaf relative water content（LRWC） of the plants under mild and moderate drought（drought for 2-8 d） were not lower than those in the control, while those under severe drought（drought for more than 10 d） were significantly lower than those in the control（P〈 0.01）. Drought stress affected the diurnal variation of photosynthesis process of camphor leaves, resulting in inhibition of organic substances accumulation and decrease of height and diameter growth. The total amount of photosynthetic pigment increased first and then decreased under drought stress, peaking at 8 d. The net photosynthetic rate（Pn）, transpiration rate（Tr）, stomatal conductance（Gs） under all drought treatments were inhibited. The photosynthesis of C. camphora saplings was influenced by the combined action of stomatal and non-stomatal factors. At the beginning of drought（after 2-8 d drought）, stomatal factors played a leading role, but during late drought（after 10 d drought） non-stomatal factors were more important ones. The apparent quantum yield（AQY）, carboxylation rate of enzyme RuBP�
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2014年第4期675-682,共8页
Chinese Journal of Applied and Environmental Biology
基金
"十二五"国家科技支撑计划项目(2011BAC09B05)
"十二五"四川省农作物育种攻关项目(2011NZ0098-10)资助~~
关键词
香樟幼树
干旱胁迫
光合特性
水分生理
形态生长
Cinnamomum camphora
drought stress
photosynthetic characteristics
water physiology
growth
