摘要
以苎麻品种川苎12号为材料,采用大田试验,设置对照(自然光照)、45%荫蔽(55%自然光照)、70%荫蔽(30%自然光照)处理,研究了荫蔽胁迫6天、12天、18天对苎麻旺长期植株光合作用、光合色素合成的影响。结果表明,荫蔽胁迫显著降低了苎麻叶片净光合速率(P_n)、气孔导度(G_s)和水分利用效率(WUE),提高了胞间二氧化碳浓度(C_i)和C_i/C_a(C_a:外界二氧化碳浓度)的比值。随着荫蔽胁迫的加重,叶绿素(Chl a)、叶绿素(Chl b)、叶绿素总含量(Chl a+b)、类胡萝卜素含量(Car)、以及Chl a+b/Car增高,叶绿素a/b(Chl a/b)降低。总之,荫蔽胁迫下苎麻光合特性的变化是对荫蔽条件的适应,变化程度与胁迫程度及持续时间密切相关。在生产中,应采取措施避免苎麻遭受较重程度的荫蔽,确保苎麻正常生长。
Light varies greatly both in time and space in the mountainous area where ramie is culti-vated in China, which affects ramie growth and fiber yield. In order to investigate the effects of shade stress on photosynthetic characteristics of ramie, the ramie cultivar Chuanzhu 12 was grown in fields and subjected to varying shade stress （i. e. 100% , 55% and 30% of sunlight, respectively） for 6, 12 and 18 days at vigorous vegetative growth stage. Then gas exchange traits and photosynthetic pigments were as-sessed. Results showed that net photosynthesis （ Pn ） , stomatal conductance （ Gs） and water use ef ciency （WUE） decreased substantially, while intercellular CO2（carbon dioxide） （ Ci） and Ci/C a（ Ca ： am-bient CO2） changed conversely in response to shade stress. Moreover, chlorophyll a （Chi） , Chi b , Chi a ＋ b ,carotenoids （Car） , and Chi a ＋ b/Car ratio increased while Chi a/b ratio decreased with aggrava-tion of shade stress. All these results indicated acclimation responses of ramie to shade. Nonetheless, the effects were closely related with the low light intensity and the duration of shade. Hence high levels of shade should be avoided for optimal growth of ramie.
出处
《中国麻业科学》
2017年第1期19-24,共6页
Plant Fiber Sciences in China
基金
国家自然科学基金项目(31271673)
