不同苹果砧木叶片解剖结构及色素含量对盐胁迫的响应

摘要

Salt resistance of three crabapple species (American Malus spectabilis, M. robusta and M. prunifolia) was compared by salt stress treatment. Plant morphology, leaf anatomical structure, pigment content and stomatal characteristics were determined in the experiment. The results show that American Malus prunifolia presented the slightest salt injury symptom in the three species under salt stress, with the most serious injury for M. prunifolia. Leaf thickness of three species decreased when the salt concentration increased, with the smallest decreasing range for American Malus spectabilis and the largest one for M. prunifolia. Pigment contents of M. robusta and M. prunifolia had a trend to decrease with the increase of salt concentration, but that of American Malus spectabilis to increase instead, with the greater decreasing range for M. prunifolia. Stomatic opening degree of the three species decreased, but the stomatal density of those species had a trend to increase with the aggravation of salt stress, with the greatest decreasing extent of stomatic opening degree and the smallest increasing range of stomatal density for M. prunifolia. According to the indexes quoted above, salt resistance strength of the tested species can be ranked as follows:American Malus spectabilis>M. robusta>M. prunifolia.%对美国黄海棠、八棱海棠和平顶海棠幼苗进行了盐胁迫处理，以比较其耐盐能力。对植株形态表现、叶片解剖结构、色素含量、气孔特征进行了观察测定，结果表明：盐胁迫下，美国黄海棠的盐害症状最轻，平顶海棠最重。3种海棠的叶片厚度均随盐浓度增加而下降，美国黄海棠降幅最小，平顶海棠降幅最大。随盐浓度增加，八棱海棠和平顶海棠的色素含量呈下降趋势，平顶海棠降幅较大，而美国黄海棠的色素含量呈增加趋势。3种海棠的气孔开张度均随盐胁迫程度增加呈减小趋势，气孔密度则呈增加趋势，其中平顶海棠气孔开张度的降幅最大，气孔密度增幅最小。综合各观测指标可知，3种海棠的耐盐性强弱依次为：美国黄海棠＞八棱海棠＞平顶海棠。