非生物胁迫对玉米杂交种及其亲本自交系产量性状的影响

以抗逆性较强玉米杂交种郑单958及其亲本(郑58、昌7-2)和抗逆性较差的杂交种陕单902及其亲本(K22、K12)为材料, 在不同种植密度(45 000株 hm^-2和75 000株 hm^-2)、施氮量(112.5 kg hm^-2和337.5 kg hm^-2)和灌水量(正常灌水和前期干旱控水)条件下, 分析了2个杂交种及其亲本产量及相关生理特性的变化规律。结果表明, 在非生物胁迫条件下(高密度、低氮和前期干旱控水), 与陕单902相比, 品种郑单958叶面积指数、SPAD值、花后干物质积累量和产量的中亲优势值分别增加18%、9%、28%和22%; 与陕单902亲本(K22、K12)比, 郑单958亲本(郑58、昌7-2)叶面积指数、SPAD值、花后干物质积累量和产量的中亲值分别增加45%、36%、51%和45%; 郑单958产量的中亲值和中亲优势显著高于陕单902, 且中亲值增幅高于杂种优势值。玉米杂交种郑单958较陕单902增产的同时, 增强了对非生物逆境适应的能力。玉米杂交种的抗逆性来自亲本自交系。玉米杂交种抗逆性强在于增强了花后叶片光合能力(较高的LAI和SPAD值), 促进了花后干物质积累。

Effects of Abiotic Stress on Yield Traits of Maize Hybrids and Their Parental Inbred Lines

The field experiments were conducted to study the changes of grain yield and concerned physiological traits in stress-tolerant maize variety Zhengdan 958 and its parental inbred lines (Zheng 58 and Chang 7-2), as well as stress-sensitive maize variety Shaandan 902 and its parental inbred lines (K22, K12) under different treatments of density (45 000 and 75 000 plants ha^?1), nitrogen application (112.5 and 337.5 kg ha^?1), and irrigation (normal irrigation and controlling water at prophase). The results showed that there were little differences in yield, mean leaf area index after anthesis, mean SPAD after anthesis, post-anthesis dry matter accumulation and harvest index between Zhengdan 958 and Shaandan 902 under resource-replete conditions (low density, high nitrogen and normal irrigation). But there were great differences in all traits (besides harvest index) between Zhengdan 958 and Shaandan 902 under abiotic stress (high density, low nitrogen and drought stress), with much higher values in Zhengdan 958 than in Shaandan 902. Compared with Shaandan 902, mid-parent values of leaf area index, SPAD, post-anthesis dry matter accumulation and grain yield of Zhengdan 958 under abiotic stress (high density, low nitrogen and drought stress) increased by 45%, 36%, 51%, and 45%, respectively, and heterosis of Zhengdan 958 increased by 18%, 9%, 28%, and 22%, respectively. The mid-parent value of yield was much higher than heterosis of yield and both of them were higher in Zhengdan 958 than in Shaandan 902. So the maize variety Zhengdan 958 showed greater tolerance to abiotic stress which was mainly inherited from its parental inbred lines. Higher SPAD and LAI after anthesis contributed to post-anthesis dry matter accumulation, resulting in higher yield and higher stress tolerance.