玉米生产上3个主推品种光合特性、干物质积累转运及灌浆特性

以当前玉米生产主推品种郑单958、先玉335和京科968为试验材料, 考察其光合特性、干物质积累与转运及籽粒灌浆特性, 以揭示高产玉米品种的产量形成特性, 为玉米高产生产提供依据。结果表明: (1)产量以京科968最高、先玉335次之、郑单958最低, 京科968分别较郑单958和先玉335高14.55%和7.93%。(2)穗位叶净光合速率和冠层光合能力表现为京科968>先玉335>郑单958, 且吐丝期>乳熟期。京科968吐丝期和乳熟期的穗位叶净光合速率分别比先玉335高7.84%和16.78%, 比郑单958高22.23%和24.44%; 冠层光合能力分别较先玉335高38.77%和58.41%, 较郑单958高50.83%和56.49%。(3)花后干物质积累量、转移量、干物质转运率和干物质转运对籽粒贡献率均以京科968最高, 分别比先玉335高13.72%、21.20%、6.32%和4.77%, 比郑单958高31.87%、39.96%、18.49%和10.42%。(4)籽粒灌浆参数在不同品种间存在较大差异, 京科968与先玉335的平均灌浆速率(0.73和0.75 g 100-grain^-1 d^-1)相当, 且均高于郑单958 (0.67 g 100-grain^-1 d^-1); 活跃灌浆期以郑单958 (53.69 d)最长、京科968 (51.02 d)次之、先玉335 (48.95 d)最短。(5)相关分析表明, 产量与净光合速率显著正相关, 与花后干物质积累量及转运率极显著正相关。京科968具有较高的光合效率、花后干物质积累量及转运率、灌浆速率及较长的灌浆持续期, 是较郑单958和先玉335高产的重要原因。

Photosynthetic Characteristics,Dry Matter Accumulation and Translocation,Grain Filling Parameter of Three Main Maize Varieties in Production

The objective of this study was to explore yield-forming characteristics of high yield maize varieties. Using three widely cultivated maize varieties Zhengdan 958 (ZD958), Xianyu 335 (XY335) and Jingke 968 (JK968), we tested grain yield, photosynthetic characteristics, dry matter accumulation and translocation, and grain filling characteristics. The yield of JK968 was the highest, and was 14.55% and 7.93% higher than that of ZD958 and XY335, respectively. The photosynthetic rate and canopy photosynthetic capacity showed JK968 > XY335 > ZD958 and silking stage > milk stage. The ear photosynthetic rate of JK968 at silking stage and milk stage was 7.84% and 16.78% higher than that of XY335, as well as 22.23% and 24.44% higher than that of ZD958, respectively. The photosynthetic capacity of JK968 at silking stage and milk stage was 38.77% and 58.41% higher than that of XY335, as well as 50.83% and 56.49% higher than that of ZD958, respectively. Dry matter accumulation after silking stage, the transfer amount of dry matter, translocation efficiency of dry matter and contribution to grain dry matter for JK968 were the highest, with 13.72%, 21.20%, 6.32%, and 4.77% higher than those of XY335, as well as 31.87%, 39.96%, 18.49%, and 10.42% higher than those of ZD958, respectively. There was a big difference in grain filling parameters among those different varieties, the average filling rate of JK968 (0.73 g 100-grain^-1 d^-1) and XY335 (0.75 g 100-grain^-1 d^-1) was higher than that of ZD958 (0.67 g 100-grain^-1 d^-1) and the active grain filling period of ZD958 (53.69 d) was longer than that of the JK968 (51.02 d) and XY335 (48.95 d). Maize yield was significantly correlated with net photosynthetic rate at P < 0.05, and with the dry matter accumulation after silking stage and the translocation rate at P < 0.01. Thus, JK968 had higher photosynthetic efficiency, dry matter accumulation after silking stage, translocation rate, grain filling rate and longer grain filling period, which is the main reason that JK968 had the higher yield than ZD958 and XY335.