作 者 ：鲁 莹1,2,束 胜1,朱为民2,郭世荣1*

期 刊 ：西北植物学报 2015年 4期 页码：787~792

关键词：小白菜；亚精胺；Ca(NO3)2胁迫；生长；光合作用；品质；

Keywords:pakchio seedlings, spermidine, Ca(NO3)2 stress, growth, photosynthesis, quality,

摘 要 ：以小白菜品种‘寒笑’为实验材料,采用营养液栽培法,研究了80 mmol/L硝酸钙胁迫下,叶面喷施0.5 mmol/L亚精胺(Spd)对小白菜生长、光合作用及其品质的影响。结果表明,(1)Ca(NO₃)₂胁迫显著抑制了小白菜幼苗生长,使植株的株高、根长、叶面积、根体积、干鲜重显著降低,而叶面喷施Spd可有效缓解胁迫对生长的抑制。(2)Ca(NO₃)₂胁迫处理植株叶绿素含量比正常营养液培养处理(对照)显著下降了54.72%,而叶面喷施Spd可以有效缓解Ca(NO₃)₂胁迫对光合色素含量的抑制,并且使植株类胡萝卜素含量比Ca(NO₃)₂胁迫处理显著提高53.33%。(3)Ca(NO₃)₂胁迫显著降低了小白菜幼苗光合作用效率,使植株净光合速率(P_n)比对照显著下降34.45%,而叶面喷施Spd可以有效缓解Ca(NO₃)₂胁迫对P_n的抑制,使植株P_n比Ca(NO₃)₂胁迫处理显著提高28.11%。(4)Ca(NO₃)₂胁迫显著降低了小白菜幼苗品质,其植株维生素C、可溶性糖、可溶性蛋白含量比对照显著降低,同期有机酸、硝酸盐含量却比对照显著升高,而叶面喷施Spd可以显著改善上述小白菜营养指标。研究认为,外源亚精胺可有效缓解Ca(NO₃)₂胁迫对小白菜生长和光合作用的抑制,提高Ca(NO₃)₂胁迫环境条件下小白菜的品质。

Abstract:‘Hanxiao’ was selected as material to study the effects of 0.5 mmol/L exogenous spermidine(Spd) on the growth and quality of pakchio seedlings under 80 mmol/L calcium nitrate stress by hydroponic culture.The results showed that:(1)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced plant growth,plant height,root length,leaf area,root volume,fresh and dry weight.Spraying 0.5 mmol/L Spd on leaf significantly promoted the growth of seedlings.(2)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced the contcents of photosynthetic pigments.Compared with CK treatment,chlorophyll content in seedlings declined 54.72% with Ca(NO₃)₂ treatment.Spraying 0.5 mmol/L Spd on leaf significantly promoted the contents of photosynthetic pigments in seedlings.Compared with Ca(NO₃)₂ treatment,carotenoid contcent in seedlings increased 53.33% with NS treatment[Ca(NO₃)₂+Spd].(3)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced photosynthesis.Compared with CK treatment,P_n of seedlings declined 34.45% with Ca(NO₃)₂ treatment.Spraying 0.5 mmol/L Spd on leaf significantly promoted P_n of seedlings.Compared with Ca(NO₃)₂ treatment,P_n of seedlings increased 28.11% with NS treatment.(4)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced quality.Compared with CK treatment,the contents of vitamin C,soluble sugar and soluble protein of seedlings significantly declined,nitrate and organic acid significantly increased with Ca(NO₃)₂ treatment.Spraying 0.5 mmol/L Spd on leaf significantly promoted seedlings above-mentioned nutritive index.These results indicated that exogenous Spd significantly promoted the growth,photosynthesis and improved the quality of pakchoi seedlings under calcium nitrate stress.