我国玉米自交系茎秆性状多样性分析

研究我国玉米自交系茎秆性状特征及其多样性,是培育宜机收玉米品种的重要前提。本研究以兰卡斯特、PB、四平头、旅大红骨和瑞德五大主要类群70份主要玉米自交系为材料,调查12个茎秆相关性状(茎高、穗位高、穗位系数、茎节数、穗位节、穗节系数、穗茎长、穗茎粗、茎鲜重、茎干重、含糖量和含水量),分析性状相关性和类群多样性。结果表明,我国地方种质四平头和旅大红骨茎秆性状表型变异丰富;灌浆期玉米茎秆含水量比较稳定;玉米植株高度与茎节长度显著相关;玉米雌、雄穗节之间的节间数比较恒定;玉米茎秆含糖量与茎节长度、茎粗、果穗着生位置有关;有效降低穗位高度应从降低果穗着生节入手;类群茎秆特征鲜明:兰卡斯特茎节较少,瑞德茎秆较粗,PB茎秆较细,旅大红骨茎秆较粗、茎节较短,四平头植株较矮、茎秆含糖量较低、干物质含量较低;兰卡斯特×四平头和兰卡斯特×PB类群间存在较强的生物量及籽粒产量杂种优势;挖掘和利用茎节较长、穗位较低的玉米地方种质是我国宜机收玉米育种的技术途径。本研究结果对玉米育种具有重要指导意义。

Diversity Analysis of Stalk Traits in Maize Inbred Lines in China

To study stalk characteristics and diversity of different main groups on maize in China is an important step for harvesting maize by mechanical means.In this study,seventy common maize inbred lines,derived from five groups of Lancaster,PB,Sipingtou,Lüda Red Cob and Reid respectively,were using to investigate their stalk-related traits,i.e.stem height(SH),ear height(EH),ear position coefficient(EPc),stem node number(SN),ear node(EN),ear node coefficient(ENc),internode length of ear(IL),internode diameter of ear(ID),stem fresh weight(FW),stem dry weight(DW),brix and moisture content(MC).A higher phenotypic variation existed in Sipingtou and Lüda Red Cob group,both of which are the local germplasms in China.At the filling stage,the moisture content of maize stalk became stable.A significant correlation in maize plant height and internode length was observed,while the number of internodes between ear and tassel was relatively constant.The sugar content of maize stalk was correlated to the length of internode,the diameter of stem and the location of ear.It′s more effective through lowering ear locating node to reduce ear height.Furthermore,maize stalk exists distint characteristics among different groups.For examples,Lancaster group has less stem node,Reid group has greater internode diameter while PB group has less one,Lüda Red Cob group has greater internode diameter and less internode length,Sipingtou group has shorter stem,less brix and dry weight.There has strong heterosis of biomass and grain yield in Lancaster×Sipingtou and Lancaster×PB.It′s an alternative strategy of mechanization breeding utilizing China local germplasm with the longer internode and the lower ear node.These results could provide important reference for maize breeding.