水分胁迫对苗期番茄叶片保护酶活性和植株形态的影响

Effect of the Water Dry Stress on the Young Plant Morphology and Protective Enzyme Activity of Greenhouse Tomato

以"金粉2号"(‘Jinfen 2’)番茄为试材,设计3个土壤水分胁迫处理,即轻度(T1)、中度(T2)、重度(T3),以正常灌溉为对照(CK),于2014年4月25日至5月30日测定了叶片保护酶活性及植株形态指标,以研究土壤水分胁迫对番茄苗期植株形态指标和叶片保护性酶活性的影响。结果表明:随水分胁迫时间增加,叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量均有不同程度增加,同期内SOD、POD、CAT活性呈现CK>T1>T2>T3趋势,MDA含量则表现为T3>T2>T1>CK,且不同处理间存在显著差异。水分胁迫下,苗期后期番茄株高、茎粗、叶片数和叶面积指数均有不同程度的减小,尤其是重度胁迫T3处理减幅最大,分别仅为CK的61.0%、56.3%、60.1%和48.3%;轻度水分胁迫能显著促进根系的生长,T1处理的根系总表面积和根尖数比CK高34.5%和38.5%,而T2根系较于CK的优势随时间逐渐减弱,T3后期根系总长度、总表面积、平均直径和根尖数分别仅为CK的30.2%、34.5%、61.5%和32.7%;研究表明水分胁迫会抑制苗期番茄地上部分的生长,但是轻度胁迫能显著促进根系生长。短期的中度胁迫有利于根系生长,但随胁迫时间延长,这种促进作用逐渐减弱甚至转变为抑制作用。而在重度胁迫下,番茄根系则受到明显的抑制。

‘Jinfen 2＇tomato was used as test material,designed 4soil moisture gradients test,from April 25 thto May 30 th,2014,and the treatments of mild,moderate,and severe water stress were T1,T2,and T3,with normal irrigation as CK,to study soil moisture stress on tomato seedling morphological index and protective enzymes.The results showed that with stress time increased,SOD,POD,CAT activity and MDA content had different degrees of increasing.Moreover in the same period SOD,POD,CAT activity presented trend of CK〉T1〉T2〉T3,while MDA content was expressed as T3T2T1CK,besides there were significant differences between different treatments.Tomato was affected less under mild stress,but the long-term moderate and severe stress would destroy cellular structure more seriously;Under water stress,the plant height,diameter coarse,leaf number and leaf area index of late seedling stage tomato all reduced to some extent,and that under the severe stress decreased more especially,only reaching 61.0%,56.3%,60.1% and 48.3% of CK respectively;mild water stress could significantly promote root growth,and the amplifications of total surface area and root tip of T1 were as much as 34.5% and 38.5% compared with CK.And T2 roots advantages compared to CK gradually weakened over time,while the final total root length,total surface area,average diameter and the number of root tips of T3 were only 30.2% 34.5%,61.5% and 32.7% of CK respectively.Studies showed that water stress could inhibit the growth of tomato above-ground part,but mild stress could significantly promote the growth of root system.Short-term moderate stress was beneficial to root growth,but with the extension of stress time,the promotion would gradually diminish or even into inhibition.And under severe stress,tomato root was obvious inhibition.The study provided the scientific basis for water management of greenhouse tomato.