种植密度对夏播玉米茎秆质量和根系表型性状的影响

Effects of Planting Density on the Stem Quality and Root Phenotypic Characters of Summer Sowing Maize

以京农科728等24个我国玉米生产大面积推广种植品种为研究材料,设置6.0(D1)和9.0(D2)万株/hm^(2)共两个种植密度处理,研究并明确不同种植密度条件下参试品种的茎秆力学和根系性状差异,为耐密高产品种选择和育种提供参考和指导。结果表明,(1)参试玉米品种的抗倒性存在较大差异,其中,以京2416为父本组配的京农科728等18个品种全生育期均未发生倒伏倒折,抗倒能力强;郑单958在生理成熟前未发生倒伏,而在生理成熟期D2密度下倒伏倒折率高达89.40%;先玉335在大喇叭口期发生根倒,倒伏率高达68.56%,生育后期未发生倒伏。(2)随种植密度增加,参试品种的株高、穗位高和穗位系数均呈升高趋势。以京2416为父本组配的京农科728等18个品种的株高、穗位高和穗位系数平均为272.13 cm、106.44 cm和39.11%,显著低于郑单958和先玉335。(3)随种植密度增加,参试品种的茎皮穿刺强度、茎秆抗折力、根系长度和根系干物重均呈降低趋势,平均为40.61 N/mm^(2)、205.06 N、217.35 m/plant和14.29 g/plant;产量呈升高趋势,平均为11724.48 kg/hm^(2)。与郑单958和先玉335相比,以京2416为父本组配的京农科728等18个品种的茎皮穿刺强度、茎秆抗折力、根系长度、根系干物重和产量具有明显优势,且耐密抗倒性强,产量潜力高,是耐密高产型品种。

The experiment was carried out to provide useful reference and guidance for the selection and breeding of maize varieties with high-resistance to density and lodging.The 24 widely planted maize varieties were selected to compare the differences of stem qualities and root traits under two plant densities of 60000(D1)and 90000(D2)plants/hm^(2).The results showed that:1)The lodging resistances of the tested 24 maize varieties differed largely,no lodging occurred during the growth period for 18 varieties such as Jingnongke728 in which used Jing2416 as the male parent.The lodging rate of Zhengdan958 reached 89.4%at physiological maturity under D2 density,but no lodging before physiological maturity.The root lodging rate of Xianyu335 reached 68.56%at the V12 stage,and no lodging occurred during the last stage.2)Plant heights,ear heights and ear height to plant height ratio of the tested 24 maize varieties increased with the increasing of plant density.Plant height,ear height and ear coefficient of 18 varieties such as Jingnongke728 in which used Jing2416 as the male parent averaged 272.13 cm,106.44 cm and 39.11%,and significantly lower than those of Zhengdan958 and Xianyu335.3)The rind penetration strength,snapping resistance,root length and dry weight of the tested 24 maize varieties averaged 40.61 N/mm^(2),205.06 N,217.35 m/plant and 14.29 g/plant respectively,and decreased with the increasing of plant density;but the yield showed an increasing trend,with an average of 11724.48 kg/hm^(2).The rind penetration strength,snapping resistance,root length and dry weight of 18 varieties such as Jingnongke728 which used Jing2416 as the male parent had obvious advantages than those of Zhengdan958 and Xianyu335,and the varieties such as Jingnongke728 were the high-yield and density-tolerance varieties.