[Effects of aluminum stress on photosynthetic characters of soybean]

With three soybean (Glycine max) varieties Zhechun No. 2, Zhechun No. 3 and 9703 as test materials, this paper studied the effects of different aluminum (Al) concentration on their photosynthetic characters. The results showed that the leaf chlorophyll content decreased by 5%-35% when Al concentration increased. Al also affected various physiological functions, e. g., stomatal resistance increased by 10%-35%, stomatal conductance decreased by 10%-40%, photosynthetic and transpiration rate decreased by 5%-40% and 20%-50%, respectively, and water utilization efficiency decreased by 15%-50%. Al stress could inhibit the photosynthesis of soybean leaves, and the inhibition was more serious in vegetative than in reproductive growth period. In addition, three test soybean varieties had definite genetic difference in response to Al toxicity.