海岸抗风植物黑松对净风和风沙流的生理响应

Physiologial response of Pinus thunbergii Parl in wind resistant to coastal wind blowing and win-drift blowing

利用野外便携式风洞仪对盆栽黑松(Pinus thunbergii Parl)幼株在不同风速(6、9、12、15、18 m/s)、不同风沙流强度(0、1.00、28.30、63.28、111.82、172.93 g cm^(-1) min^(-1))、不同时间(10、20、30、40、50 min)进行了净风和风沙流吹袭,通过测定其叶片相对含水量(Relative water content, RWC)、丙二醛(Malondialdehyde, MDA)、可溶性糖、脯氨酸含量,及超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(Catalase, CAT)、过氧化物酶(Peroxidase, POD)活力等变化规律以揭示黑松抗风沙流生长的生理适应机制。结果表明,在净风吹袭下,随着风速提高至15 m/s,黑松叶片RWC相对稳定,MDA含量和细胞膜透性小幅增加且较低,而脯氨酸含量下降17.5%。同时叶片SOD、CAT、POD活力也小幅增加。在风沙流吹袭下,随着风沙流风速提高至15 m/s,黑松在短时低风速吹袭时叶片RWC就开始下降(4.4%),叶片平均MDA含量、细胞膜透性分别较对照增加61.3%、25.6%,脯氨酸含量增加8.9%,叶片SOD、 CAT、POD活力分别较对照增加21.5%、30.4%、13.9%。同风速吹袭下,风沙流处理组叶片抗逆生理指标均高于净风处理。如15 m/s风速下,风沙流处理组叶片平均MDA、脯氨酸、可溶性糖含量分别较净风处理组高4.7%、36.6%、22.1%, SOD和CAT活力较净风处理组高21.5%、36.5%。在高风速(18 m/s)净风和风沙流吹袭中,随着风吹时间延长(50 min),叶片MDA、脯氨酸、可溶性糖含量和SOD、CAT、POD活力均下降。研究表明,风吹袭中黑松叶片较高抗脱水力与其抗风性相关。风沙流引发的叶片失水可能是黑松抗逆生理变化的诱因。风吹袭下叶片失水能快速促使脯氨酸的积累和维持可溶性糖含量,以维护细胞中水分平衡。同时,叶片失水又快速激活抗氧化保护酶系统来防御和清除氧自由基、抑制膜脂过氧化维护细胞膜的完整性使黑松在风沙流吹袭中生存。黑松较强的渗透调节能力和抗氧化防御系统在其适应风沙流吹袭中起重要的生理调控作用。

The experiment was designed that there were different wind speed(6, 9, 12, 15 and 18 m/s), different wind-drift blowing(0.00, 1.00, 28.30, 63.28, 111.82 and 172.93 g cm^(-1) min^(-1)), and five wind blowing times(10, 20, 30, 40 and 50 min) in spring, 2018 in Yantai, Shandong Province by using outdoor portable wind tunnel to understand the how physiological responses of Pinus thunbergii Parl seedlings to wind blowing and wind-drift blowing. The relative water content(RWC), malondialdehyde(MDA) contents, membrane permeability, osmotic regulators(soluble sugar, proline), and antioxidant enzyme activities(superoxide dismutase(SOD), catalase(CAT), peroxidase(POD)) were tested in the leaves of seedlings of Pinus thunbergii Parl under the previous treatments. The results showed that under treatment of wind blowing, with increasing of wind speed to 15 m/s, the RWC was not changed, MDA content and membrane permeability increased slightly, while the proline content decreased, and the activities of SOD, CAT, and POD were slightly enhanced in the leaves of Pinus thunbergii Parl.. Under treatment of wind-drift blowing, with increasing of wind speed to 15 m/s, the RWC decrease, the membrane permeability and the contents of MDA and proline increased, and the activities of SOD, CAT, POD enhanced. At same wind speed, the value of each resistant physiological index under treatment of wind-drift blowing was higher than those under treatment of wind blowing in the leaves of Pinus thunbergii Parl. However, under wind blowing and wind-drift blowing at 18 m/s, the contents of MDA, proline, soluble sugar, and the activities of SOD, CAT, POD decreased with time extension to 50 min in the leaves of Pinus thunbergii Parl. It indicated that leaves of Pinus thunbergii Parl had stronger capacity of resistant dehydration, which was correlated with its ability of resistance to wind blowing. But cell dehydration induced by wind-drift blowing would be a main factor, which could not only promote the accumulation of proline and keeping on soluble sugar content to maintain water balance, but also activate antioxidant defense system to scavenge oxygen free radicals, and inhibit membrane lipid peroxidation to preserve the integrity of cell membranes. It suggested that Pinus thunbwould beergii had stronger capacity of osmotic adjustment and antioxidant defense system could be an important physiological adaptation mechanism for it to resistance to wind-drift blowing.