Abstract: 【Objective】Understanding diversity profile of crop germplasm is the basis of effective conservation and efficient utilization of genetic resources. The present study investigates the phenotypic diversity of four flowering-related traits, including tasseling (T), pollen-shedding (S) tassel-pollenshedding interval (TPI) and anthesis-silking interval (ASI).【Method】799 maize landrace accessions from the core collection preserved in Chinese National Genebank were planted according to multiple-environment trail (MET), and the phenotypic observation of 4 flowering-related traits, including T, S, TPI and ASI, were recorded during the reproduction stage of these accessions. Shannon-Weaver diversity index was calculated based on the phenotypic estimates of these 4 flowering-related traits, and ANOVA was conducted to test the significance of differentiation among the phenotypic estimates and Shannon-Weaver diversity indices.【Result】The results of ANOVA showed that the differentiation of phenotypic estimates of all the 4 flowering-related traits significant at 1% level among 32 provinces/regions, and except TPI, the differentiation of Shannon-Weaver diversity indices of T, S, and ASI significant at 1% level. Among the 6 maize regions of China, phenotypic estimates of all these 4 flowering-related traits significant at 1% level, and the Shannon-Weaver diversity indices of T, S, and ASI significant at 5% or 1% level. Among the 6 maize regions in China, the Shannon-Weaver diversity indices of T, S, TPI, and ASI of accessions from Southwest Montane Maize Region are 1.85, 1.90, 0.88, and 1.20 separately. 【Conclusion】There exists high level of phenotypic diversity of T, S, TPI, and ASI among the maize landrace accessions conserved in Chinese National Genebank, and among 6 maize regions in China, the average phenotypic diversity level of the four flowering-related traits of the accessions of Southwest Montane Maize Region was significantly higher than those of the other 5 maize regions, which indicates that there exist considerably high protection value and utility potential in the maize germplasm of Southwest Montane Maize Region.

Key words: maize, landrace, flowering-related trait, phenotypic diversity