咸淡水交替灌溉对南疆设施番茄酶活性及产量品质的影响

Effect of Alternate Brackish and Freshwater Irrigation on Enzyme Activity and Yield Quality of Tomatoes in Southern Xinjiang Facilities

为了探究不同咸淡水交替灌溉对设施番茄土壤盐分胁迫响应及产量品质的影响,以“秦岭蔬越”番茄品种为研究对象,共设置W1(淡咸咸)、W2(淡咸淡)和W3(咸淡淡)3种咸淡水交替灌溉方式,并以淡水灌溉(CK)对照。结果表明:在咸淡水交替灌溉方式下,番茄生育期土壤盐分出现逐渐累积趋势,整体表现为W1>W2>W3处理,且W1、W2处理土壤盐分表聚现象较为严重,而W3处理土壤盐分有向下淋洗趋势,土壤表层积盐较轻。不同咸淡水交替灌溉后,由于土壤盐分累积程度不同,使番茄受到盐分胁迫的差异较大,其中番茄叶片内丙二醛(MDA)、脯氨酸(PRO)、可溶性蛋白(SP)、可溶性糖(SS)及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)含量均有不同程度增加。由相关性分析可知,土壤盐分与番茄叶片CAT、PRO呈极显著性正相关(P<0.01),与叶片SS呈显著性正相关(P<0.05),说明番茄通过改变各种保护酶活性及渗透物质含量提高自身抗逆性,以应对盐分胁迫危害。通过对比分析,W3处理番茄可溶性固形物、硝酸盐、Vc和总酚含量及产量均高于对照,说明适宜的咸淡水交替灌溉方式能够提高番茄品质和产量。

In order to investigate the effects of alternate brackish and freshwater irrigation on the response of soil salinity stress and yield quality of tomatoes in facilities,three alternate brackish and freshwater irrigation methods,three treatments,including W1(freshwaterbrackish-brackish),W2(freshwater-brackish-freshwater),and W3(brackish-freshwater-freshwater),were set up,with freshwater irrigation(CK)as the control.One tomato variety,Qinlingshuyue,was chosen as the model vegetable in this study.The results showed that soil salinity accumulated gradually during tomato growth period under alternate brackish and freshwater irrigation,with an overall trend of method W1>W2>W3,and the soil salinity surface aggregation was more serious with method W1 and W2,while soil salinity in method W3 had a tendency of downward leaching,resulting in light salt accumulation on soil surface.After alternate irrigation with brackish and freshwater,the soil salinity accumulated to different levels.Tomatoes were thus under salt stress to varying degrees,with malondialdehyde(MDA),proline(PRO),soluble protein(SP),soluble sugar(SS)and superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)contents in tomato leaves found to increase to different degrees.The correlation analysis showed that soil salinity was in highly significant and positive correlation with CAT and PRO of tomato leaves(P<0.01)and with soluble sugars(SS)of leaves(P<0.05),indicating that tomato improved its resistance to the salt stress hazard by changing the activities of various protective enzymes and the content of osmotic substances.Comparative analysis showed that the soluble solids,nitrate,Vc and total phenol contents and yield of tomatoes under method W3 were higher than those under the CK,indicating that the appropriate alternate irrigation method of brackish and freshwater can improve the quality and yield of tomatoes.