【摘要】 以切花菊‘神马’为试材,研究了叶面喷施不同浓度(0、1、2、3、4和5 mmol·L-1)的外源尿囊素(All)对Na Cl胁迫(140 mmol·L-1)下菊花叶绿素荧光特性和活性氧清除酶系统的影响。测定了Na Cl胁迫下菊花叶片的叶绿素荧光参数、活性氧含量和抗氧化酶活性以及植株生长量。结果表明,不同浓度的All处理均可以提高Na Cl胁迫下菊花的ΦPSII、Fv/Fm和qP值,使菊花植株的ETR上升,其中3 mmol·L-1 All处理的植株Fv/Fm值升高最显著,是Na Cl胁迫植株的1.73倍,qP较对照降幅最小;3、4、5mmol·L-1浓度的All处理均可以减缓qN的上升。喷施All处理10 d时,2、3、4 mmol·L-1的All显著增加了Na Cl胁迫下植株的株高,以3 mmol·L-1All处理的增加最多,提高了3.85%;各浓度All处理的菊花植株地上部干重较Na Cl胁迫植株均有不同程度地增加,3 mmol·L-1 All处理增加了8.21%,达到显著性差异(P<0.05);3 mmol·L-1 All处理植株与没有Na Cl胁迫的植株(CK)株高和地上部干重差异均不显著;3 mmol·L-1All处理10 d时,菊花叶片中H2O2的含量以及O2﹒—产生速率最低,较Na Cl胁迫处理的植株分别降低了21.90%和27.92%,且SOD的活性最强,是Na Cl胁迫处理的2.30倍。综合分析,外源All处理在清除Na Cl胁迫下菊花叶片中活性氧的累积以及缓解PSII活性的抑制方面有着重要作用,对Na Cl胁迫下菊花植株生长抑制起到缓解作用,且以3 mmol·L-1的All处理效果最佳。更多还原

【Abstract】 The effects of exogenous allantoin(All) on Chlorophyll fluorescence characteristics and reactive oxygen scavenging enzyme system of cut flower Chrysanthemum(Chrysanthemum morifolium ‘Jinba’) under Na Cl stress(140 mmol·L-1) were studied by spraying different concentrations of allantoin(0, 1, 2, 3, 4 and 5 mmol·L-1) on the leaves of Chrysanthemum. The chlorophyll fluorescence parameters, active oxygen content, antioxidant enzyme activities of chrysanthemum leaves and plant growth were measured. The results showed that all treatments with different concentrations of allatoin could increase the values of Φ PSII, Fv/Fm and qP of Chrysanthemum under Na Cl stress, and increase ETR of Chrysanthemum plants. Among them, the value of Fv/Fm with 3 mmol·L-1 allatoin treatment was the most significant, which was 1.73 times higher than that of Na Cl stress plants, and qP decreased the least compared with the control(CK). The increase of qN could be slowed down by allatoin at the concentration of 3,4,5 mmol·L-1. After spraying allantoin for 10 days,the concentration of 2, 3 and 4 mmol·L-1 significantly increased the plant height under Na Cl stress, with 3 mmol·L-1 allantoin treatment increasing the plant height by 3.85%. The above ground dry weight of Chrysanthemum plants under all concentrations increased to varying degrees compared with those under Na Cl stress, and the 3 mmol·L-1 allantoin treatment increased by 8.21%, reaching a significant difference(P<0.05). There was no significant difference in plant height and shoot dry weight between 3 mmol·L-1 allantoin and no Na Cl stress(CK). At 3 mmol·L-1 allantoin treatment, the content of H2 O2 and the rate of O2-production in leaves of Chrysanthemum were the lowest, which were 21.90% and 27.92% lower than were the lowest, which were 21.90% and 27.92% lower than those under Na Cl stress, and the activity of SOD was the strongest,which was 2.30 times higher than that of Na Cl stress. Comprehensive analysis showed that the treatment of exogenous allantoin played an important role in scavenging the accumulation of reactive oxygen species(ROS) and alleviating the inhibition of PSII activity in Chrysanthemum leaves under Na Cl stress, it can alleviate the growth inhibition of Chrysanthemum under Na Cl stress, and the best treatment was 3 mmol·L-1 allantoin.更多还原