不同水高效基因型小麦根系特性差异分析

Analysis on Root Characteristics of Wheat Genotypes with Different Water Use Efficiency

研究不同水高效基因型小麦的根系特性差异,可为抗旱节水小麦品种选育过程中正确选择根系指标提供科学依据。以抗旱品种石新633(DRI=1.300)和不抗旱品种河农58-3(DRI=0.713)为试材,在旱处理(足墒播种出苗后,小麦生育期不再补充灌溉)条件下,采用大田取根方法,比较了不同抗旱性小麦品种的根系特性差异及其在土壤中的垂直分布情况。结果表明:抗旱品种0~160 cm土层的根总长度、根体积、根面积和根干重均>非抗旱品种,其中,80~160 cm深层土壤的根总长度和根干重差异达到了显著水平。相关分析结果显示,0~80 cm土层的根总长度、根体积、根面积和根干重与抗旱性均呈负相关,其中,60~80 cm土层的根总长度、根体积和根面积与抗旱性的相关程度达到了显著水平(相关系数分别为-0.508、-0.428、-0.540);80~160 cm深层土壤的根总长度、根体积、根面积、根干重与抗旱性均呈正相关,其中,140~160 cm土层的根总长度、根体积和根干重与抗旱性的相关程度达到了显著水平。干旱胁迫下抗旱节水冬小麦主要利用深层土壤中的水分,由此认为,主要是分布在深层土壤的根系对抗旱性起作用。在选育抗旱节水冬小麦品种时,应注意加大深层根系的比例,选择浅层和中层根系比例相对较小的品种。

The aim of the study was to evacuate variation of root characteristics among wheat genotypes with different water use efficiency,to provide a root selection index.Two different genotype Shixin 633（drought tolerance,DRI=1.300）,Henong 58-3（drought sensitive,DRI=0.713） and a single drought treatment（no irrigation after seedling） were employed for the test.A field root sampling method was selected to evaluate the variation of root characters and distribution within soil.The results showed that within 0-160 cm profiles,the root length and dry weight were higher for drought tolerance variety then sensitive one and significant higher within80-160 cm layer.The results of correlation analysis showed that all the total root length,root volume,total root area and root dry weight within 0-80 cm were negatively correlated with drought tolerance,there were significance correlation between total root length,root volume and root total area of 60-80 cm profile to drought tolerance（-0.508,-0.428,-0.540,respectively）,in contract,there were positive correlation between total length,volume area,dry weight and drought tolerance in 80-160 cm profiles.The relationship between root length,volume,dry weight in 140-160 cm profiles and drought tolerance reached a significant level.The results showed that under water stress,drought tolerance ability of winter wheat was due to the ability of deep water use and the deep root characters.It means to select deep root proportion in deep profile and relatively small proportion in shallow profiles in drought tolerance breeding program is a useful protocol.