摘要
为了探讨外源6-苄氨基嘌呤(6-BA)对紫花苜蓿(Medicago sativa)叶片光合作用、抗氧化系统及结荚率的调控作用,以新牧4号紫花苜蓿(Medicago sativa ‘Xinmu No.4’)为试验材料,现蕾期叶面喷施10、20、30 mg·L^(-1)的6-BA,以喷等量清水为对照,研究外源6-BA对苜蓿盛花期叶片光合参数、荧光参数、抗氧化酶活性、渗透调节物质及结荚率的影响。结果表明,20 mg·L^(-1)的6-BA处理显著(P<0.05)提高了苜蓿叶片的净光合速率(P_n)、蒸腾速率(T_r)、最大光化学效率(F_v/F_m),增强了苜蓿叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性,使叶片中积累了脯氨酸和可溶性糖,减少了叶片中过氧化氢的积累,显著提高了苜蓿的结荚率及单株种子产量(P<0.05);~130 mg·L–处理,虽提高苜蓿叶片抗氧化酶活性,并且主要荧光参数高于对照,但Pn低于对照,该处理中P_n的下降由非气孔限制因素主导。20 mg·L^(-1)的6-BA可提高盛花期苜蓿叶片的光合速率,抗氧化酶活性,减小光合机构的损伤,有利于苜蓿叶片光合作用的进行,提高苜蓿的结荚率及种子产量。
The role of exogenous 6-benzylaminopurine (6-BA) in the regulation of photosynthesis and the antioxidant system in alfalfa leaves was evaluated to provide a theoretical and research basis the application of this cytokinin in the growth and development of alfalfa. Xinmu No. 4 alfalfa (Medicago sativa ‘Xinmu No. 4 ’) plants were examined in this study. 6-BA solutions at concentrations of 10, 20, and 30 mg·L^-1 were sprayed onto the leaves of alfalfa during the squaring period;the control plants were sprayed with water. The effects of exogenous 6-BA on photosynthetic parameters, fluorescence parameters, antioxidant enzyme activities, osmotic adjustment substances, and rate of podding were examined during the flowering stage of alfalfa. The results showed that after treatment with 20 mg·L^-1 6-BA, the photosynthetic rate, transpiration rate, and maximum photochemical efficiency of the alfalfa leaves were significantly increased and the activities of superoxide dismutase, peroxidase, and catalase in the leaves of alfalfa were enhanced. The increase accumulation of proline and soluble sugars and the reduced accumulation of hydrogen peroxide in the leaves significantly improved the fruiting rate and seed yield per plant. In the 30 mg·L^-1 treatment, although the antioxidative enzyme activity was increased and the main fluorescence parameters were higher than those of the control, the rate of photosynthesis was decreased compared to the control. The decrease in the photosynthetic rate under this treatment was dominated by non-stomatal limiting factors. In conclusion, 20 mg·L^-1 6-BA can increase the photosynthetic rate and antioxidant enzyme activity as well as reduce damage to the photosynthetic mechanism of alfalfa leaves at the flowering stage. Moreover, increasing photosynthesis in the alfalfa leaves can increase the fruiting rate and seed yield.
作者
宋佳琦
王玉祥
张博
SONG Jiaqi;WANG Yuxiang;ZHANG Bo(College of Pratacultural and Environmental Sciences,Xinjiang Agricultural University / Western AridRegion Grassland Resources &Ecology Key Lab,Urumqi 830052,Xinjiang,China)
出处
《草业科学》
CAS
CSCD
2019年第3期720-728,共9页
Pratacultural Science
基金
农业部国家牧草产业技术体系岗位科学家项目(CARS-34)
农业部公益性行业专项"甘肃农业大学新疆荒漠区苜蓿高效种植关键技术研究与集成示范"(201403048-8)
