Phenotypic Trait Selection in Construction of a Core Collection for Maize(Zea mays L.)

The core collection is the representative of the germplasm collection.The selection of the phenotypic traits is an important prerequisite for constructing a core collection with phenotypic traits.Five data types,i.e.qualitative traits(QT1),quantitative traits(QT2),asterisked traits(AT),traits without asterisk(TWA) and integrated traits(IT),were compared for their efficiency in constructing core collections of 1003 maize inbred lines based on the test parameters of the core collection.The results showed that the genetic diversity of qualitative traits of core was collections constructed based on the five trait data ranked in the following order: ITAT≈TWA and ITQT2≈QT1,respectively.In the same way,the genetic diversity of quantitative traits of core collections was constructed based on the five trait data ranked in the order of IT≈ATTWA and ITQT2QT1,respectively.By integrating the genetic diversities of qualitative and quantitative traits,the results showed the following order:IT≈ATTWA,ITQT2QT1,and the efficiency of core collections constructed based on AT is close to IT.The number of AT is less than IT,so AT is very convenient for practical applications with better efficiency for the construction of core collection.