西北春玉米子粒乳线和水分变化与灌浆特性的关系

Relationship between Grain Milk Line and Moisture Change and Grain Filling Characteristics of Northwestern Spring Maize

选择7个不同类型的春玉米品种,通过对灌浆期子粒乳线和含水量、子粒重量的连续测定,明确乳线与子粒水分、子粒水分与授粉后积温的关系,为适宜机械粒收品种筛选提供依据。结果表明,7个参试品种授粉至生理成熟天数、积温需求和百粒重差异明显,灌浆后45 d乳线下移到子粒62.4%~76.2%处,62~70 d乳线先后消失。随着乳线下移子粒含水率呈明显的直线下降趋势,乳线比例可以预测子粒水分和灌浆天数变化,生理成熟后达到低水分粒收要求所需天数在品种间均可相差1倍。参试品种子粒含水率与授粉后积温均符合Logistic Power非线性增长模型。授粉后,7个品种子粒含水率降低到机械收获子粒含水率25%时,各品种所需授粉后积温1298.6~1463.2℃·d,平均1375.7℃·d;达到18%~22%子粒含水率时,所需授粉后积温为1414.8~1827.9℃·d。因此,选择生理成熟后脱水快和收获期子粒水分低的品种,延期收获降低水分含量是提高西北春玉米粒收质量的关键。

The experiment was carried out with seven corn varieties selected by continuously measurement of grain milk line,water content and grain weight during filling period,to clarify the relationship between milk line and grain moisture,grain moisture and accumulated temperature after pollination.Provide a basis for the selection of suitable mechanical grain harvest varieties for selecting varieties suitable for mechanical harvesting of grains.The results showed that the days from pollination to physiological maturity,accumulated temperature requirements,and 100-kernel weight of the seven varieties tested were significantly different.The milk lines moved down to 62.4%-76.2%at 45d after grouting and disappeared at 62-70 d after grouting.The grain moisture content showed a clear linear downward trend,while the milk line moving downward.There was a significant difference in grain dehydra⁃tion rate among varieties before and after physiological maturity.The ratio of the milk line can predict the changes of grain moisture and filling days.The difference in the time it took that grain moisture content of the tested varieties reduced the requirements of mechanical grain harvesting since physiological was doubled.The grain moisture con⁃tent of the tested cultivars and the accumulated temperature after pollination are consistent with the Logistic power nonlinear growth model.The grain moisture dropped to 25%,22%and 18%when the accumulated temperature after pollination reached average 1375.7℃·d,1493.2℃·d and 1687.3℃·d,changing from 1298.6℃·d to 1463.2℃·d,1414.8℃·d to 1600℃·d and 1594.8℃·d to 1827.9℃·d between cultivars.Therefore,selecting varieties with fast dehydration after physiological maturity and low grain moisture during the harvest period,delaying harvest and re⁃ducing moisture content are the key to improving the quality of spring corn harvest in Northwest China.