脱落酸对檀香幼苗生长、光合及叶片 抗氧化酶活性的影响

为了探讨脱落酸对檀香幼苗生长的影响,以半年生檀香幼苗为试材,研究了盆栽条件下叶面喷施不同质量浓度脱落酸(ABA)(0、1、10、100 mg/L)对檀香幼苗生长、光合特性及抗氧化酶活性等生理指标的影响。结果表明:较低质量浓度的脱落酸(1 mg/L)可以显著增强檀香幼苗的苗木质量指数(QI),提高叶片的净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、和叶绿素a(Chl a)含量,降低叶片中丙二醛(MDA)含量; 较低浓度的ABA处理后叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性均有所提高,檀香幼苗的生物量积累也得到增加。随着ABA施用量的增加(10～100 mg/L),檀香幼苗生物量、QI、P_n、Chl a含量等均降低,抗氧化物酶活性下降,幼苗生长在一定程度上受到抑制。结果说明:低浓度的外源ABA可通过提高檀香幼苗叶片抗氧化酶活性来降低膜脂过氧化,通过增加光合作用来提高檀香幼苗的长势和生物量积累,使苗木质量指数显著增强; 实验验证以1 mg/L的ABA处理效果最好。

Effects of abscisic acid on growth,photosynthesis and antioxidant enzyme activities of Santalum album seedlings

In this paper, we investigated the effects of abscisic acid(ABA)(0, 1, 10 and 100 mg/L)on growth, photosynthesis characteristics and antioxidant enzyme activities of Indian sandal wood(Santalum album)seedlings by conducting a container culture experiment. The results showed that the net photosynthesis rate(P_n), stomatal conductance(G_s), transpiration rate(T_r), chlorophyll a(Chl a)content in leaves of sandal wood seedlings were significantly increased after 1 mg/L ABA treatment, while malondialdehyde(MDA)content in leaves were significantly decreased, the activities of superoxidase(SOD), peroxidase(POD), catalase(CAT)were statistically improved, and biomass accumulation, quality index(QI)were also promoted. With the ABA concentration increase(10-100 mg/L), P_n, chl a content and antioxidant enzymes activities were decreased, the growth of sandal wood seedlings were also inhibited slightly. These findings indicated that exogenous low concentration ABA could enhance the capacity of scavenging active oxygen species, and improve photosynthesis, protect sandal wood seedlings from lipid peroxidation. As a result, to promote seedling growth and quality of sandal wood seedlings, the optimal ABA concentration for foliar application of sandal seedlings was 1 mg/L.