玉米自交系苞叶表型可塑性差异分析

为确定玉米5大杂优群苞叶表型可塑性在异地引种的稳定性和敏感性,收集了我国玉米5大杂优群50份自交系,2014年在海南省三亚市、2015年在北京市和2017年在辽宁省铁岭市3种环境下测定各杂优群的自交系在不同环境的苞叶性状,计算苞叶性状的变异系数,分析杂优群间苞叶长度可塑性(phenotypic plasticity of husk length, PHL)、宽度可塑性(phenotypic plasticity of husk width, PHW)和层数可塑性(phenotypic plasticity of husk layer number, PHN)的差异和杂优群内的相关性,比较不同环境和生长时期各气象因子的变化。结果显示:苞叶性状受环境影响显著;在全部测定群体、旅大红骨和唐四平头群中PHL与PHW呈显著正相关,在瑞德群中PHL与PHN呈极显著负相关;不同血缘玉米种质的苞叶表型可塑性存在明显差异,PHL与PHW表现出协同调控的特点;旅大红骨群的苞叶长度和PB群的苞叶长度、宽度对环境不敏感,这2个性状异地引种时会保持稳定;兰卡斯特群PHL较大,且符合苞叶性状南长北短的要求,这类育种材料适合南北方异地引种;气象因子中平均温度和湿度在玉米生长前期差异较大,日照时间在玉米生长的前、中和后期都有一个差异较大的时段。因此,高温区适时早播,低温区适时晚播,有利于减少环境间的苞叶差异。

Variation of phenotypic plasticity for husk traits among maize inbred lines

The phenotype plasticity of husk plays essential roles in disease resistance,insect infection and the rate of grain dehydration during the introduction of maize inbred lines from different environments. In this article,the husk traits of 50 inbred lines from 5 heterosis groups (referred to as heterotic group) in 3 environments including Sanya City,Hainan Province in 2014,Beijing City in 2015 and Tieling City,Liaoning Province in 2017 were measured. The coefficient of variation of husk traits was calculated. The variations of phenotypic plasticity of husk length (PHL),phenotypic plasticity of husk width (PHW) and phenotypic plasticity of husk layer number (PHN) among heterotic groups and the correlation within heterotic groups were analyzed. The changes of meteorological factors in different environments and growth periods were compared. The results showed that the traits of husks were significantly affected by environment. Among all lines,Lüda Red Cob and TangSPT groups,PHL and PHW were significantly positively correlated. While in Reid group,PHL and PHN were extremely significantly negative correlated. The phenotypic plasticity of husk among different maize germplasms had significant variations. PHL and PHW had the characteristics of coordinated regulation. The husk length in Lüda Red Cob group,husk length and width in PB group were insensitive to environments. These two traits remained stable during introduction to other environments. The PHL in Lancaster group was higher than that in other groups,meeting the requirements of the long husk in the South and the short husk in the North. This kind of breeding material is suitable for introduction in different places in the north and south. The average temperature and humidity in the meteorological factors were quite different at the early growth stage of maize. There was a big difference in the sunshine time at the early,middle and late growth stages of maize. It is indicated that sowing early in high temperature area and late sowing in low temperature area is beneficial to reduce the difference of husk traits among environments.