干旱胁迫和氮素形态对豌豆根系生长的影响

Effect of Drought Stress and Nitrogen Forms on Root Morphology of Pea

研究干旱胁迫和氮素形态对豌豆根系生长的影响,以期为旱农区豌豆的生长调控提供理论依据。采用盆栽方法,研究了2种氮素形态下55%的土壤相对含水量进行15天干旱胁迫对不同时期豌豆根系生长的影响。结果表明,氮素对根系生长的影响因形态而异,硝态氮有利于促进正常供水下根系的伸长生长,铵态氮有利于提高不同水分条件下的根直径。干旱胁迫对根系生长的影响也因氮素形态而异,3种胁迫方式均显著降低了胁迫期间及花荚盛期硝态氮营养下的根长、根体积、根表面积;干旱胁迫有利于降低成熟期根系的衰败速率,产生了等量补偿或超补偿效应。综上所述,硝态氮营养有利于促进豌豆根系生长,孕蕾期干旱胁迫后复水对成熟期根系生长的补偿效果最好。

The paper aims to provide a theoretical basis for the growth regulation of pea in arid area by exploring the effects of drought stress and nitrogen forms on root growth of pea.Pot experiment was adopted to study the effects of 2 nitrogen forms and drought stress of 55% relative water content for 15 days on root growth of pea during different periods.The results showed that： the effects of nitrogen on root growth varied with nitrogen forms,and NO_3--N promoted root elongation under normal water condition,while NH_4~＋-N improved root diameter under normal and water stress condition; in addition,the influence of drought stress on root growth also varied with nitrogen forms,and the root length and volume as well as surface area under 3 drought stress forms during stress period and flowering stage significantly decreased under NO_3--N condition;furthermore,drought stress was beneficial to reducing root decay rate during maturity stage,which epitomized equivalent-compensation or over-compensatory effects on root growth.In conclusion,NO_3--N was beneficial to promoting root growth and the compensatory effect of rewatering after drought stress during bud stage on root growth during maturity period was the best.