盐碱胁迫对‘阳光玫瑰’葡萄氮素吸收利用的影响

Effects of Salt-alkali Stress on Nitrogen Absorption and Utilization in‘Shine Muscat’Grapevine

以‘阳光玫瑰’为试材,研究盐碱胁迫对葡萄根系形态,Na^(+)、K^(+)含量,叶绿素相对含量(SPAD)值,氮素吸收、利用和响应等方面的影响。结果表明,盐碱胁迫抑制了葡萄干鲜物质的积累和根系的正常生长;降低了叶片中的SPAD值,削弱了光合作用;降低了叶片和根系中K^(+)含量,而使Na^(+)含量和Na^(+)/K^(+)比值增加,打破了离子平衡;盐碱胁迫降低了叶片和根系中NO_(3)^(-)含量和叶片中NH_(4)^(+)含量,但增加了根系中NH_(4)^(+)的含量,叶片和根系中的总氮含量也显著降低,抑制了对氮的吸收。同时,盐碱胁迫还抑制了葡萄叶片中硝酸还原酶(Nitrate reductase,NR)、亚硝酸还原酶(Nitrite reductase,NiR)、谷氨酰胺合成酶(Glutamine synthetase,GS)、谷氨酸合酶(Glutamate synthase,GOGAT)的活性和根系中NR、GS、GOGAT的活性,增加了根系中NiR的活性;同位素K15NO3标记分析表明,盐碱胁迫降低了葡萄幼苗15N的利用率。

Using'Shine Muscat'as a test material,the effects of salt-alkali stress on root morphology,Na^(+)and K^(+)content,SPAD value,nitrogen absorption,utilization,and response of grapevine were investigated.The results showed that salt-alkali stress inhibited the accumulation of dry and fresh matter accumulation and the normal growth of roots.SPAD value of leaves was decreased and photosynthesis was weakens.K^(+)content in leaves and roots were decreased,while Na^(+)content and Na^(+)/K^(+)ratios were increased,the disrupting ion balance was broken.Salt-alkali stress reduced the content of NO_(3)^(-)and NH_(4)^(+)in leaves and roots,but increased NH_(4)^(+)content in roots,and the total nitrogen content in leaves and roots also decreased significantly,inhibited nitrogen absorption.Meanwhile,saltalkali stress inhibited the activities of nitrate reductase(NR),nitrite reductase(NiR),glutamine synthetase(GS),and glutamate synthase(GOGAT)in leaves and the activities of NR,GS and GOGAT in roots,and increased the activity of NiR in roots.Isotope K15NO3 labeling analysis showed that salt alkali stress reduced the 15N utilization efficiency of grapevine seedlings.