盐胁迫对怀玉山三叶青2个栽培种试管苗生理特性和次生代谢产物的影响

Effects of Salt Stress on Physiological Characteristics and Secondary Metabolites of Plantlets of Two Cultivars of Tetrastigma hemsleyanum Diels et Gilg in Huaiyu Mountain

为探究盐胁迫对怀玉山三叶青2个栽培种(‘怀玉1号’‘怀玉2号’)试管苗生理特性和次生代谢产物的影响,为其大棚基质高效栽培提供依据,本研究设置不同质量浓度(0、2、4、6、8、10 g·L^(-1))的NaCl胁迫处理,分析其对怀玉山三叶青2个栽培种试管苗生长及生理特性的影响。结果表明:(1)低盐胁迫(2~4 g·L^(-1))时,怀玉山三叶青2个栽培种试管苗无死亡,对株高和植株干质量无显著影响;中高盐胁迫(6~10 g·L^(-1))时,2个栽培种试管苗的死亡率显著提高,株高、地上和地下部干质量显著下降。(2)随着盐胁迫浓度的升高,怀玉山三叶青2个栽培种试管苗的游离脯氨酸(Pro)、可溶性蛋白(SP)、可溶性糖(SS)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均先升高后降低,除‘怀玉1号’可溶性糖含量在0.2 g·L^(-1) NaCl处理时最高外,‘怀玉1号’‘怀玉2号’各指标分别在4、6 g·L^(-1) NaCl处理时达到峰值;MDA含量和相对电导率均持续升高;‘怀玉1号’‘怀玉2号’叶绿素a和叶绿素b及总叶绿素含量分别在2~4、2~6 g·L^(-1) NaCl处理时与对照差异不显著,而后均显著下降。综合分析,‘怀玉1号’‘怀玉2号’试管苗的耐盐阈值分别为4、6 g·L^(-1)。(3)隶属函数分析和主成分分析结果表明,怀玉山三叶青2个栽培种试管苗的耐盐性为‘怀玉2号’>‘怀玉1号’。(4)随着盐胁迫的不断加重,‘怀玉1号’和‘怀玉2号’试管苗叶片的黄酮和多酚含量呈先升后降趋势,而多糖含量则呈直线下降趋势。本试验探究了盐胁迫对怀玉山三叶青试管苗生理特性和次生代谢产物的影响,可为今后解决其高山大棚栽培中可能遇到的盐胁迫问题提供理论依据。

To explore the effects of salt stress on physiological characteristics and secondary metabolites of plantlets of two cultivars of Tetrastigma hemsleyanum Diels et Gilg(‘Huaiyu 1’, ‘Huaiyu 2’) in Huaiyu Mountain and to provide the basis for their substrate high efficient cultivation in greenhouse, the effects of different concentrations of NaCl(0, 2, 4, 6, 8, 10 g·L^(-1)) on physiological characteristics and secondary metabolites were studied in this paper. The results showed that:(1) Under low salt stress(2~4 g·L^(-1)), there were no significant effects on the plant height and dry mass of the two cultivars, and the plantlets did not die;under medium and high salt stresses(6~10 g·L^(-1)), the plant height, aboveground and underground dry mass of the two cultivars significantly decreased, and the mortality increased significantly.(2)With the increase of salt concentration, the contents of proline(Pro), soluble protein(SP), soluble sugar(SS) and the activities of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) first increased and then decreased. Except that the soluble sugar content of ‘Huaiyu 1’ was the highest at 0.2 g·L^(-1) NaCl, the indexes of ‘Huaiyu 1’ and ‘Huaiyu 2’ reached the peak at 4 g·L^(-1)and 6 g·L^(-1) NaCl, respectively. MDA content and relative conductivity increased continuously. The contents of chlorophyll a, chlorophyll b and total chlorophyll of ‘Huaiyu 1’ and ‘Huaiyu 2’ were not significantly different from the control at 2~4 g·L^(-1) and 2~6 g·L^(-1) NaCl, respectively, and then decreased significantly. Through comprehensive analysis, the salt tolerance thresholds of ‘Huaiyu 1’ and ‘Huaiyu 2’ were 4 g·L^(-1)and 6 g·L^(-1), respectively.(3)The results of subordinate function analysis and principal component analysis showed that the salt tolerance of two cultivars was ‘Huaiyu 2’> ‘Huaiyu 1’.(4) With the aggravation of salt stress, the contents of flavonoids and polyphenols in the leaves of ‘Huaiyu 1’ and ‘Huaiyu 2’ showed a first rising and then decreasing trend, while the polysaccharides content showed a straight decreasing line downward trend. This experiment explored the effects of salt stress on physiological characteristics and secondary metabolites of plantlets of T. hemsleyanum Diels et Gilg in Huaiyu Mountain, which could provide a theoretical basis for solving the problems of salt stress that may be encountered in alpine greenhouse cultivation in the future.