ABSTRACT. Understanding genetic diversity, population structure, and linkage disequilibrium is a prerequisite for the association mapping of complex traits in a target population. In this study, the genetic diversity and population structure of 40 waxy and 40 normal inbred maize lines were investigated using 10 morphological traits and 200 simple sequence repeat (SSR) markers. Based on a population structure analysis, the 80 maize inbred lines were divided into three groups: I, II, and admixed. Significant marker-trait associations were identified between the markers and the 10 morphological traits, which were studied according to the model used to confirm the association. Using a general linear model, the lowest R 2 value (9.03) was detected in umc1139, which was associated with ear number, and the highest (43.97) was in umc1858, which was associated with plant height. Using a mixed linear model, the lowest R 2 value (18.74) was in umc1279, which was 7503 Agronomic-trait association mapping in maize inbred lines ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 7502-7518 (2015) associated with ear weight; the highest (27.66) was in umc1858, which was associated with 100-kernel weight. The SSR markers identified in the present study may serve as useful molecular markers for selecting important yield and agronomic traits. These results will be useful for marker-assisted selection in maize breeding programs, to help breeders choose parental lines and markers for crosses.

ABSTRACT. In this study, we compared the efficiency of simple sequence repeat (SSR) and sequence specific amplified polymorphism (SSAP) markers for analyzing genetic diversity, genetic relationships, and population structure of 87 super sweet corn inbred lines from different origins. SSR markers showed higher average gene diversity and Shannon's information index than SSAP markers. To assess genetic relationships and characterize inbred lines using SSR and SSAP markers, genetic similarity (GS) matrices were constructed. The dendrogram using SSR marker data showed a complex pattern with nine clusters and a GS of 53.0%. For SSAP markers, three clusters were observed with a GS of 50.8%. Results of combined marker data showed six clusters with 53.5% GS. To analyze the genetic population structure of SSR and SSAP marker data, the 87 inbred lines were divided into groups I, II, and admixed based on the membership probability threshold of 0.8. Using combined marker data, the population structure was K = 3 and was divided into groups I, II, III, and admixed. This study represents a comparative analysis of SSR and SSAP marker data for the study of genetic diversity and genetic relationships in super sweet corn inbred lines. Our results would be useful for maize-breeding programs in Korea.

ABSTRACT. We observed 3 types of non-parental banding patterns using simple-sequence repeat primers in a recombinant inbred line maize population developed from 2 inbred lines, Mo17 and KW7. We observed alleles that were not present in either of the parents, known as non-parental alleles. Although non-parental alleles are a consequence of genetic variation, they are less common in progenies derived from inbred lines. Generally, when non-parental alleles are encountered during genotyping analysis, they are either deleted from the analysis or considered to be missing data. However, before making a decision regarding how to treat non-parental alleles, it is important to understand the mechanism through which they form. There are a variety of potential reasons for the formation of non-parental bands, including recombination or mutation in the simple-sequence repeat region, residual heterozygosity in parental lines, or chromosomal aberrations resulting from rearrangements and transposons. In this article, we discuss the potential reasons behind the formation of the non-parental alleles observed in our data.