黄淮海地区两类主栽玉米杂交种果穗和籽粒含水量及脱水特征研究

采用连续取样测定（每3天1次）和3个关键期取样生理成熟期(M),成熟后10天(M+10 d)和后20天(M+20 d)]取样测定相结合的方法比较了黄淮海地区7个主栽玉米杂交种的籽粒,穗轴和苞叶含水量及脱水速率,发现7个杂交种可被归为以‘郑单958’和‘先玉335’为代表的两类：958类（‘郑单958’、‘伟科702’和‘中科11’）和335类（‘先玉335’、‘登海605’、‘裕丰303’和‘农华101’）。两类杂交种在生理成熟前没有明显差异,从M到M+20 d,335类杂交种籽粒含水量由32.0%快速下降到22.6%,可以用一次线性方程y=-0.6757x+69.59逼近,而958类杂交种由34.1%缓慢下降到28.2%,可以用二次曲线方程y=0.0078x ²-1.3481x+85.065逼近。从M到M+20 d,335类杂交种的穗轴含水量由59.0%降到45.3%,降幅13.7%;而958类由71.0%降到59.1%,降幅11.9%。335类杂交种苞叶较厚但层数较少,籽粒较窄较长,水分散失较快。结果表明335类玉米杂交种更适合机械化穗粒收。

Ear and Kernel Moisture and Dry-down Rate of Two Groups of Maize Hybrids in Huanghuaihai Area

The cob, bract and kernel moisture and their rate of dehydration of major commercial hybrids were compared to obtain valuable information for crop management and breeding of fast kernel dehydration hybrids. Data were collected from seven major commercial corn hybrids in Huanghuaihai area using two sampling schemes: the multi-point continuous sampling (every third day) and three key time points sampling kernel physical maturity (M), 10 days after M (M+10 d) and 20 days after M (M+20 d)], and the seven hybrid cultivars could be divided into two groups represented by ‘Zhengdan 958’ and ‘Xianyu 335’, which were 985 group (‘Zhengdan 958’, ‘Weike 702’ and ‘Zhongke 11’) and 335 group (‘Xianyu 335’, ‘Denghai 605’, ‘Yufeng 303’ and ‘Nonghua 101’). There was no obvious difference in the two groups of hybrid cultivars before physiological maturity, from M to M+20 d, the water content in grain of 335 group decreased from 32.0% to 22.6%, which could fit by y=-0.6757x+69.59. While that of 958 group decreased slowly from 34.1% to 28.2%, and could fit by y=0.0078x ²-1.3481x+85.065. From M to M+20 d, the content in cob of 335 group decreased from 59.0% to 45.3% with a decreasing range of 13.7%, while that of 958 group decreased from 71.0% to 59.1% with a decreasing range of 11.9%. 335 group had rather thick bract with fewer plies, longer kernel, fast water desorption. The results showed that 335 group is more suitable for mechanization harvest.