天竺桂凋落叶添加对凤仙花生理特性的影响

采用盆栽试验,通过向土壤(每盆8kg)中添加0(CK)、20(L20)、40(L40)和80g·pot-1(L80)天竺桂(Cinnamomum japonicum)凋落叶,模拟其自然分解对凤仙花(Impatiens balsamina)生理特性的影响。结果显示:(1)天竺桂凋落叶处理显著增加了凤仙花现蕾前期和现蕾期叶片H2O2含量,同时显著抑制了凤仙花现蕾前期、现蕾期和盛花期超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性。(2)凋落叶添加处理显著增加了凤仙花现蕾前期抗坏血酸(ASA)含量,但现蕾期和盛花期ASA含量却显著下降。(3)添加凋落物处理显著降低了现蕾前凤仙花叶片MDA含量,但显著增加了现蕾期MDA含量,而盛花期MDA含量在L20、L80处理下显著降低,在L40处理下则显著增加。(4)天竺桂凋落叶添加对可溶性蛋白和可溶性糖两种渗透调节物质含量影响不显著。(5)凋落叶处理显著抑制了凤仙花地径生长和地上生物量积累。(6)天竺桂凋落叶中主要化感物质可能有香豆素、桉叶油醇、肉桂醛、反式石竹烯和松油醇等。研究认为,非酶促活性氧清除系统可能在凤仙花抵御化感物质氧化胁迫过程中发挥着比酶促系统更为重要的作用,其中的ASA在氧化胁迫的早期过程扮演着重要角色;天竺桂凋落叶添加处理所造成的氧化胁迫可能超过了两类活性氧清除系统的清除能力,对凤仙花膜系统造成明显伤害,导致其地径和生物量积累显著降低。

Effect of Cinnamomum japonicum Leaf Litter Addition on the Physiological Properties of Impatiens balsamina

In order to investigate the effects of Cinnamomum japonicum leaf litter addition on the physiological properties of Impatiens balsamina,a pot experiment has been conducted.Four litter addition treatment levels (0,20,40,80 g·pot^-1) were applied.The results showed that:(1)Litter additions significantly increased H₂O₂ concentration in leaf of I.balsamina in pre-squaring stage.(2)The activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) were inhibited significantly during pre-squaring,squaring and full bloom stages.(3)Ascorbic acid(ASA) concentration was significantly increased in pre-squaring stage,but decreased significantly in squaring and full bloom stages.(4)The basal diameter growth and aboveground biomass of I.balsamina were depressed by the litter additions significantly.(5)Coumarin,eudesmol,cinnamic aldehyde,trans-caryophyllenethe and terpineol may the main allelochemicals in C.japonicum leaf litter.The study suggests that the non-enzymatic ROS scavenging system may more important than the enzymatic system for I.balsamina.Ascorbic acid may play an important role in the resistance of oxidative stress in pre-squaring stage of I.balsamina.The oxidative stress derived from litter additions may exceed the scavenging capacities of the two systems,and as a result,the basal diameter growth and aboveground biomass accumulation were depressed by the injury of membrane system of I.balsamina.