NaCl处理对半高丛蓝莓的生长发育及光合特性的影响

Effects of NaCl on Growth and Photosynthesis of Semi-dwarf Blueberry Bushes

【目的】鉴定半高丛蓝莓的耐盐性和耐盐范围,为盐碱地区的蓝莓引种、栽培提供理论依据。【方法】采用盆栽加盐的方式进行人工模拟盐胁迫环境,研究不同浓度[0(CK)、30、60、90、120、150、180、210mmol·L^-1]NaCl处理50d对2年生半高丛蓝莓品种北陆(Northland)的生物学特性、生理生化指标、光合作用以及其净光合速率(Pn)、蒸腾速率(Tr)、胞间二氧化碳浓度(Ci)和气孔导度(Gs)等光响应的影响。【结果】(1)30、60、90mmol·L^-1NaCl处理对蓝莓生长发育有促进作用;120mmol·L^-1NaCl处理下蓝莓促进作用解除,生长势与CK相近;150、180mmol·L^-1NaCl处理下蓝莓促进作用解除;210mmol·L^-1NaCl为半高丛蓝莓的耐盐存活临界浓度,导致植株死亡;(2)在NaCl浓度≤90mmol·L^-1时,蓝莓植株生长状况优于CK,株高、冠幅增加,地上部、地下部干鲜重增加;蓝莓叶片可溶性糖含量增加,脯氨酸(Pro)含量增加,超氧化物歧化酶(SOD)活性增加,细胞膜相对透性增大,丙二醛(MDA)含量升高;(3)各处理下蓝莓植株Pn、Tr、Gs的日变化曲线呈上升趋势,Ci呈下降趋势,Pn、Tr、Ci的光响应曲线呈上升趋势,Gs呈下降趋势,以60mmol·L^-1NaCl处理最为显著。【结论】半高丛蓝莓具有一定的耐盐性,耐NaCl范围为0~180mmol·L^-1;盐碱地区土壤含盐量低于90mmol·L^-1时,可以考虑选择蓝莓品种北陆种植。

【Objective】 Salt tolerance of blueberry plants were studied for possible cultivation in saline-alkali lands.【Method 】 A pot experiment was conducted using varied salt additions[0 (CK), 30, 60, 90,120,150,180, and210 mmol·L -1 )] NaCl in a medium to artificially simulate the environmental stress.Two- year-old seedlings of semi-dwarf Vaccinium Northland blueberry were treated under the stress for 50d.Effects on the physiological and biochemical properties, as well as the photosynthesis, net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci), and stomatal conductance (Gs), were determined.【Result】(1) A salt concentration at 30, 60 or 90 mmol·L -1 promoted the seedling growth, but the enhancing effect disappeared when it reached120 mmol·L -1, where the result became similar to CK.Further increase to150 or180 mmol·L -1 inhibited the seedling growth.At210 mmol·L -1, a threshold that caused plant death was observed.(2) When the salt concentration was less or equal to 90 mmol·L -1, the blueberry seedlings grew better than CK with increased plant height, crown width, dry and fresh weights of shoots, and soluble sugar content in leaves.The biochemical indices, such as Pro, superoxide dismutase (SOD) activity, relative permeability of cell membrane, and malondialdehyde (MDA) content, were elevated as well.(3) The daily variations on Pn, Tr and Gs of the treated plants were on an upward trend, but Ci downward.The responses of Pn, Tr and Ci to light exposure showed an upward trend, while that of Gs downward.These effects were most significant under 60 mmol·L -1 NaCl.【Conclusion】The semi-dwarf blueberry bushes exhibited a significant salt tolerance within 0-180 mmol·L -1 .Northland blueberry was conceivably a variety that could be cultivated on soil that has a salt content below 90 mmol·L -1 .