为明确气候变暖下玉米根系对温度升高的响应特征,采用盆栽试验,研究了全生育期梯度增温对玉米冠根形态、生长发育和产量的影响。结果表明,随着温度升高,玉米总根层数减少2层,总根条数减少34.74%-45.05%,冠根总干重减少33.18%-50.26%,根冠比平均降低26.34%-36.11%。不同节位的冠根总干重、根长度、根表面积和根体积随温度升高显著降低,温度越高,降幅越大。增温2℃时,玉米各节位轴根的根干重、根平均直径、根长度、根表面积和根体积比CK降低26.30%、8.63%、26.67%、26.85%和23.67%,增温4℃则分别比CK降低42.62%、22.27%、44.28%、52.60%和46.34%；增温对玉米侧根生长影响大于轴根,增温2℃时,侧根的根干重、根平均直径、根长度、根表面积和根体积比CK降低16.09%、5.56%、34.86%、34.50%、34.48%,温度升高4℃则分别比CK降低28.37%、8.82%、52.65%、51.37%、55.35%。温度每升高1℃,玉米生物量和籽粒产量平均减少5.17%和16.15%。根形态指标与生物量、产量极显著正相关。郑单958根系对增温适应性优于先玉335,表现为根量多,根长度长、根表面积大的品种对温度升高的适应能力更强。

To explore the effect of elevated temperature on maize crown root growth traits, the pot-experiment was conducted to study root morphological, growth and development characters and yield with elevated temperature in greenhouse. The results showed that layers of crown root were less 2 layers than that of CK under elevated temperature treatments. Total root numbers were decreased significantly by 34.74% to 45.05%. Crown root dry weight was decreased by 33.18% to 50.26%, and root-shoot ratios were decreased by 26.34% to 36.11%. Root dry weight, root length, root surface area and root volume of crown root each layer were significantly decreased under elevated temperature treatments, and the more higher temperature the more decreasing. When temperature was elevated by 2℃, Axial root dry weight, axial root diameter, axial root length, axial root surface area and axial root volume of maize were decreased on average by 26.30%, 8.63%, 26.67%, 26.85% and 23.67%, respectively. When temperature was elevated by 4℃, these root indicators were decreased on average by 42.62%, 22.27%, 44.28%, 52.60% and 46.34%, respectively. There were much more negative effects on growth of lateral root than that of axial root with elevated temperature. Lateral root dry weight, lateral root diameter, lateral root length, lateral root surface area and lateral root volume under elevated temperature by 2℃ treatment were decreased on average by 16.09%, 5.56%, 34.86%, 34.50% and 34.48%, respectively. And they were decreased on average by 28.37%, 8.82%, 52.65%, 51.37% and 55.35%, respectively under elevated temperature by 4℃ treatment. Biomass and grain yield were decreased by 5.17% and 16.15% in average with elevated temperature by 1℃. The traits of root were extremely significant positively related to maize biomass and yield. The adaptation of Zhengdan 958 to elevated temperature was greater than that of Xianyu 335 in two cultivars. That indicated that the varieties with more root weight, longer root length and larger root surface area had better adaptability to elevated temperature.

国家现代农业产业技术体系专项资金资助(CARS-02-20)。