| In this research, the inbred line L26 was defined as P1, which has the mutation trait of Roll-leaf-above-ear, and inbred line 095 as P2, which has normal leaves, to create the descendant generations for genetic analysis and gene mapping the mutation trait and the other trails by means of SSR marker technique. The main results were as follows:①Combined with the 9 generations phenotype, such as P1, P2, F1, F2, B1, and B2 of cross L26×095 and F1, B1, B2 of cross095×L26, the Roll-leaf-above-ear trait was caused by one recessive gene's mutation, which was defined as rlae.②The improvement of important agricultural traits should consider the correlation coefficients between these traits in breeding practices. The correlation analysis was taken between 17 traits phenotype datum as like Stem Diameter (SD), Ear Height (EH), et al., by means of SPSS12.0. It showed that there are wide correlations between these traits and production, which supports the conclusions that it is very complicated to increase the production and it is very necessary to improve these traits in breeding practices. Meanwhile, the correlation coefficients of Ear Length and Kernels per Row, Ear Length and Kernel Weight per Ear, Ear Diameter and No. of Rows per Ear, Ear Diameter and Kernel Weight per Ear, Kernels per Row and Kernel Weight per Ear were exceed 0.7, showed as height-height correlation, which implied that one thait's improvement of the pairs would lead to the other traits' change inevitably.③An F2 group of L26×095 was used as the mapping generation, and 507 SSR primers, which evenly cover on the maize genome (referred to the database of http://www.maizegdb.org), were selected to screen the parental polymorphism. Only 108 primers were screened out to havepolymorphism between the two parents, and still only 98 pimers were used to construct the linkage map. This SSR linkage map composed of 15 groups and covered 98 loci. It spanned maize genome about 810.3 cM, with average distance of 8.27cM between makers, which was fit for preliminary QTLs mapping.④Based on the former map, the rlae was elementarily ascertained neighbors of markers bnlgl350a (3) and bnlg1117 (3) of chromosome 10 while the accurate loci was still uncertain.⑤With interval mapping procedure, 73 QTLs were detected for the former 17 traits. Wherein these, 2, 3, 4, 8, 8, 2, 6, 4, 5, 4, 1, 3, 6, 5, 2, 4, 6 QTLs were respectively identified for Stem Diameter, Ear Height, Plant Height, Branch No. of Tassel, No. of Leaves, Leaf Area, Leaf Orientation Value, Leaf Shape Coefficient, Length of Bare Tip of Ears, Ear Length, Ear Diameter, No. of Rows per Ear, No. of Kernels per Row, Cob Diameter, 200-kernel Weight, Kernel Rate and Kernel Weight per Ear, and QTLs totally accounted for 25.3%, 23.3%, 29.5%, 82.3%, 95.4%, 13.9%, 53.6%, 59.7%, 51%, 43.8%, 5%, 29.5%, 41.3%, 49%, 14.7%, 253.4% and 361.6% of phenotypic variation of each trait. Among these QTLS, qLSC2, qLSC3, qLSC4, qKR2, qKR3, qKR4, qKR5 and qKR6 could account for 82.7%, 82.7%, 82.8%, 69.9%, 70%, 69.9%, 71.6% and 72% in the turns, which show the characters of major gene.⑥For the traits significantly correlated, some QTLs of different traits were detected at the same locus on chromosome. It was presumed that pleiotropic effects or linkage of QTLs might lead to correlation between traits, and it also foreshows that once the traits had the significant relationships on phenotype, they might have the same or extraordinary neighborly locus on chromosome.
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