减源对密植夏玉米品种抗倒伏性能及产量的调控效应

Regulating effects of leaf source reduction on lodging resistance and yield of summer maize varieties in dense planting

于2019年和2020年采用二因素裂区试验设计,主区为不同耐密性高产品种:郑单958(紧凑型)和正大12(半紧凑型);副区为减源强度:在花前一周从上至下分别移除植株1片叶(D1)、2片叶(D2)、3片叶(D3)和4片叶(D4),以不做任何处理为对照(CK)。对乳熟期和蜡熟期的玉米植株形态、基部第3节间的穿刺强度、折断力及籽粒产量构成因素等指标进行分析,探究密植玉米植株抗倒伏性能及籽粒产量对叶源减少的响应。结果表明:乳熟期,D1、D2处理的株高、穗位高和穗位系数较CK分别显著降低1.03%、3.03%,2.29%、6.17%和1.32%、4.17%,茎粗和单位茎长干物质量较CK分别增加4.15%、33.94%和1.91%、5.72%。蜡熟期,D2处理时郑单958的穿刺强度和折断力较CK分别提高了26.51%和32.44%,正大12的穿刺强度和折断力较CK分别提高了55.28%和21.53%。灌浆期,郑单958和正大12的D2处理可溶性糖含量较CK分别增加2.91%和10.83%,木质素含量分别增加2.74%和6.90%,D3、D4处理的纤维素含量较CK分别降低1.17%和0.47%、11.57%和13.72%。D2处理的总倒伏率显著降低且产量最高,郑单958达11203.90 kg·hm^(-2),正大12达11742.34 kg·hm^(-2)。可见,适度去除顶部1~2片叶可优化夏玉米株型,通过影响茎粗使节间、单位节间干物质量得到更好地分配,从而提升抗倒伏性能,改善干物质向籽粒的分配进程,最终实现产量提高。

A two-factor split-zone experiment was conducted in 2019 and 2020.The experiment involved different density-tolerance maize cultivars(main plot)and leaf source reduction intensity(sub plot).The two maize cultivars were Zhengdan 958(compact)and Zhengda 12(semi-compact).The leaf source reduction intensity including 1 leaf(D1),2 leaves(D2),3 leaves(D3)and 4 leaves(D4)of the plant were removed from top to bottom one week before flowering,and the treatment with no leaves removal was used as control(CK).The plant morphology,puncture strength and breaking force of the third internode at milk-ripe stage and waxy-ripe stage,grain yield components of maize were analyzed to explore the response of lodging resistance and grain yield to leaf source reduction.The results showed that the plant height,spike height,and spike coefficient were significantly lower by 1.03%、3.03%,2.29%、6.17%and 1.32%、4.17%,and the stem diameter and dry matter per stem length were increased by 4.15%、33.94%and 1.91%、5.72%in D1 and D2 treatments compared to CK at lactation.At the waxy-ripe stage,the puncture strength and breaking force of Zhengdan 958 under the D2 treatment were 26.51%and 32.44%higher than CK,and that in Zhengda 12 were 55.28%and 21.53%higher.During the filling stage,the soluble sugars of Zhengdan 958 and Zhengda 12 increased by 2.91%and 10.83%respectively,and the lignin contents increased by 2.74%and 6.90%under the D2 treatment,compared with CK.The cellulose contents of the D3 and D4 treatments were decreased by 1.17%and 0.47%,11.57%and 13.72%than CK,respectively.The total lodging rate of the D2 treatment was significantly decreased and the yield was the highest,Zhengdan 958 reached 11203.90 kg·hm^(-2),Zhengda 12 reached 11742.34 kg·hm^(-2).In summary,reducing leaf sources improved the lodging resistance of dense planting summer maize.There was leaf redundancy in the dense planting maize population.Therefore,moderate removal of the top 1~2 leaves optimized the plant architecture of summer maize,improved the lodging resistance by affecting stem diameter,allowing better distribution of dry matter,and finally increased the yield.