两个小麦品种的抗旱性鉴定与评价

Identification and Evaluation of Two Wheat Varieties under Drought Stress

为探索小麦品种‘西农100’和‘周麦18’的抗旱特性,采用大田和盆栽组合试验,通过测定根部性状、萌发率、生理指标和显微结构等,分析其抗旱性。结果表明:‘西农100’的根质量、平均根数、根表面积与体积显著低于‘周麦18’,在水培25 d时,‘西农100’的总根长与最大根长显著高于‘周麦18’。两个品种在PEG胁迫下的发芽率都达到了90%以上,苗期抗旱性等级均为极强。两个品种在苗期干旱胁迫下的幼苗存活率较高,相对含水量无显著差异。‘西农100’在水分临界期受到干旱胁迫后,其产量显著低于‘周麦18’;两个品种的旗叶抗氧化酶(SOD、POD、CAT)活性、渗透调节物质(Pro、可溶性蛋白)含量与小麦的抗旱性呈正相关,复水后抗氧化酶活性随时间逐渐降低至对照水平,渗透调节物质含量显著降低;‘西农100’和‘周麦18’在干旱胁迫下的叶片均出现明显结构变化;总体来说,在水分临界期‘西农100’抗旱性整体弱于‘周麦18’。

To explore the drought resistance characteristics of wheat varieties‘Xinong 100’and‘Zhoumai 18’,a combination of field and pot experiment was conducted to analyze the drought resistance of the wheat varieties by measuring the root character,germination rate,physiological index and microscopic structure.The results showed that the root mass,root average number,root surface area and volume of‘Xinong 100’were significantly lower than those of‘Zhoumai 18’,and the total root length and maximum root length of‘Xinong 100’were significantly higher than those of‘Zhoumai 18’after 25 days of hydroponics.The germination rate of the two varieties under PEG stress reached more than 90%,and the drought resistance grade of the seedling stage was identified as very strong.The seedling survival rate of the two varieties was extremely strong under drought stress,and there was no significant difference in relative water content.The yield of‘Xinong 100’was significantly lower than that of‘Zhoumai 18’after drought stress at critical moisture stage.The activities of antioxidant enzymes(SOD,POD,CAT)and the contents of osmotic regulatory substances(Pro,soluble protein)in flag leaves of the two varieties were positively correlated with the drought resistance of wheat.The activity of antioxidant enzymes decreased gradually to the control level after rehydration,and the content of osmotic regulatory substances decreased significantly.The leaves of‘Xinong 100’and‘Zhoumai 18’showed obvious structural changes under drought stress.In general,the drought resistance of‘Xinong 100’is weaker than that of‘Zhoumai 18’duing the critical moisture period.The comparison between the drought resistance of‘Xinong 100’and‘Zhoumai 18’was conducted by measuring several traits and indexes.This study provides a reference for the popularization and application of these two varieties.