长江中游南部春玉米子粒不同阶段脱水规律研究

Study on the Grain Dehydration Regularity of Spring Maize in the South Area of Middle Reaches of Yangtze River

以脱水速率不同的3个品种先玉335(XY335)、登海605(DH605)和郑单958(ZD958)为供试材料,春季分3个播期种植,分析长江中游南部玉米不同阶段子粒脱水特征以及子粒脱水与灌浆、气象因子的关系。结果表明,3个品种在3个播期的子粒脱水速率均表现为先上升后下降、后期又快速上升。后期快速升高的起点前后子粒脱水速率呈现不同的特征。将后期子粒脱水速率快速上升的起点作为分隔点,前期为T1阶段,后期为T2阶段。T1阶段,子粒脱水速率与灌浆速率极显著正相关(r=0.845**,P<0.01),与各气象因子无显著相关关系,表现生理脱水特征;T2阶段,子粒脱水速率与温度相关的气象因子及平均日照时数显著正相关,与降雨量显著负相关,表现净脱水特征。子粒脱水速率品种间差异主要体现在后期,XY335、DH605后期脱水速率高于ZD958;以子粒含水率为评价尺度时,XY335、DH605后期脱水速率快速升高的时间早于ZD958。结果表明,玉米子粒后期脱水速率受品种基因型与气象因子的影响,收获时含水率低的品种具有后期快速脱水启动早、脱水速率更快的特征。

Three varieties of Xianyu 335(XY335),Denghai 605(DH605)and Zhengdan 958(ZD958)with different dehydration rates were used as materials,planted in Changsha on three sowing dates.The characteristics of dehydration of maize grain at different stages and the relationship between grain dehydration and filling and meteorological factors were analyzed.The results showed that the dehydration rates of the three varieties sown at three different times all increased firstly and then decreased,further followed a rapid increase/rise at the later stage.The rate of grain dehydration before and after the rapid rise of the late stage showed different characteristics.The starting point of the rapid increase of the grain dehydration rate in the later period was taken as the separation point,the early stage was the T1 stage,and the later stage was the T2 stage.At the T1 stage,the grain dehydration rate was significantly positively correlated with the grain filling rate(r=0.845**),but no significant correlation with meteorological factors,showing physiological dehydration characteristics;T2 stage,grain dehydration rate were significantly positively correlated with temperature-related meteorological factors and average sunshine hours,and significantly negatively correlated with rainfall,showing net dehydration characteristic.The difference of grain dehydration rate among varieties was mainly reflected at the later stage.The grain dehydration rate of XY335 and DH605 were higher than ZD958 at the later stage.When the grain moisture content was used as the evaluation scale,the dehydration rate of XY335 and DH605 increased rapidly earlier than ZD958 at the late stage.The results showed that grain dehydration rate of maize at the later stage was affected by genotype and meteorological factors,the varieties with low moisture content at harvest stage had the characteristics of earlier rapid dehydration and faster dehydration at the later stage.