2个不同抗旱性小麦品种耗水特征及根系生理特性对开花期干旱的响应

为探明不同抗旱性小麦品种的耗水特征、根系生理特性及产量对开花期干旱的响应,以抗旱性强品种新春6号（XC 6）和抗旱性弱品种新春22号（XC 22）为试材,在土柱栽培和大田条件下设置常规灌溉（CK）、开花期轻度干旱（T1）和中度干旱（T2）处理,研究干旱胁迫对滴灌麦田耗水特征、不同土层根系生理特性和产量的影响。结果表明：开花期干旱后2个小麦品种全生育期耗水量和耗水强度均表现为CK>T1>T2,拔节—孕穗期耗水模系数最大。T1处理复水后伤流液、根系活力、根系水力学导度（Lpr）、过氧化氢酶（CAT）、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性及可溶性蛋白（SP）含量显著提高,进而促进地上部质量和千粒重增加,提高产量和水分利用效率。与XC 22相比,XC 6伤流液、Lpr、根系活力、SOD、POD、SP含量、地上部质量以及产量均显著增加,T1处理下XC 6的伤流液、Lpr较XC 22高5.4%~25.1%,2.2%~15.7%;0—20,20—40,40—60 cm土层SOD （6.9%~20.0%,2.6%~24.7%和3.6%~31.1%）、POD （4.1%~19.1%,3.9%~25.2%和3.7%~21.6%）、CAT （7.8%~15.2%,8.3%~13.3%和10.8%~13.3%）活性及SP （4.5%~20.4%,0.8%~29.4%和1.3%~7.9%）含量显著高于XC 22。根质量、地上部质量和产量与耗水量呈二次抛物线关系,与伤流液、Lpr、MDA和CAT活性呈显著正相关。水分处理与品种互作对Lpr、POD、CAT活性及SP含量影响显著。因此,抗旱性强品种开花期轻度干旱可降低耗水量,提高根系SP含量及抗氧化酶活性,增强根系活力,促进地上部质量提高,有利于提高产量和水分利用效率。

Response of Water Consumption and Root Physiological Characteristics of Two Different Drought-tolerant Wheat Varieties to Anthesis Stage Drought

In order to explore the water consumption characteristics, root physiological characteristics and yield response to anthesis stage drought of different drought-tolerant wheat varieties, taking drought-tolerant variety Xinchun 6 (XC 6) and drought-intolerant variety Xinchun 22 (XC 22) as the experimental materials, conventional irrigation (CK), mild drought (T1) and moderate drought (T2) at anthesis stage were set up under soil column cultivation and field conditions to investigate the effects of drought stress on water consumption characteristics, root physiological characteristics of different soil layers and yield of drip irrigation wheat field. The results showed that after anthesis stage drought, the water consumption and water consumption intensity of the two wheat varieties in the whole growth period were CK>T1>T2, and the water consumption modelcoefficient reached the maximum at the jointing-booting stage. After rehydration with T1 treatment, the bleeding fluid, root activity, hydraulic conductivity (Lpr), the avtivity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) and soluble protein (SP) content significantly increased, which promoted the increase of shoot mass and 1 000 grain weight, and improved yield and water use efficiency. Compared with XC 22, bleeding fluid, Lpr, root activity, SOD, POD, SP content, shoot quality and yield of XC 6 all significantly increased. In T1 treatment, the bleeding fluid and Lpr of XC 6 were 5.4% to 25.1%, 2.2% to 15.7%higher than those of XC 22, respectively, and the SOD (6.9% to 20.0%, 2.6% to 24.7% and 3.6% to 31.1%), POD (4.1% to 19.1%, 3.9% to 25.2% and 3.7% to 21.6%), CAT (7.8% to 15.2%, 8.3% to 13.3% and 10.8% to 13.3%) activities and SP content(4.5% to 20.4%, 0.8% to 29.4% and 1.3% to 7.9%) in 0-20, 20-40 and 40-60 cm soil layers were significantly higherthan those of XC 22, respectively. Root mass, shoot mass and yield had a quadratic parabola relationship with water consumption, and there was a significant positive correlation with bleeding fluid, Lpr, MDA and CAT activities. The interaction between water treatment and varieties had significant effects on Lpr, POD, CAT and SP content. Therefore, mild anthesis stage drought of drought-tolerant variety could reduce water consumption, improve root SP content and antioxidant enzyme activity, so as to enhance root activity, improve shoot mass, and improve yield and water use efficiency.