Leaflet number of soybean controlled by Lf2 locus is the important trait in photosynthesis and plant type. The objective of this research was to identity molecular markers linked to the lf2 locus. A total of 115F2 plants were derived from a cross between normal three-leaflet type Sinpaldalkong (Lf2Lf2) and seven-leaflet mutant type T255 (lf2lf2). All leaflet counts of parents and F2 individual plants were made in the field on fully expanded leaves on the main stem when terminal growth of the main stem had ceased. One-thousand 10-mer oligonucleotide RAPD primers and 664 SSR primers were used. The segregation ratios of 3 : 1 were observed in the F2 population and the Chi-square values strongly suggested that the seven-leaflet was controlled by a single recessive gene. A genetic map was constructed from the 15 segregating markers (9 RAPDs, 5 SSRs, 1 lf2 locus). OPAD03 and OPAI13 RAPD markers were linked to the lf2 locus that controlled seven-leaflet type at a distance of 20.5 and 23.5 cM, respectively. Molecular markers identified in this study linked with lf2 locus will be helpful to locate lf2 locus on the public soybean molecular linkage map and would be useful for tagging the lf2 locus that controls seven-leaflet trait.

Leaf chlorophyll-deficient mutants controlled by y9 locus have been observed frequently and are useful in genetic stud-y9 locus. A mapping population con-sisting of 94 F2 progeny was derived from a cross between normal green leaf Clark (Y9 ) and chlorophy

Soybean seeds contain high amounts of isoflavones that display biological effects and isoflavone content of soybean seed can vary by year, environment, and genotype. Objective of this study was to identify quantitative trait loci that underlie isoflavone content in soybean seeds. The study involved 85 F2 populations derived from Korean soybean cultivar 'Kwangkyo' and wild type soybean 'IT182305' for QTL analysis associated with isoflavone content. Isoflavone content of seeds was determined by HPLC. The genetic map of 33 linkage groups with 207 markers was constructed. The linkage map spanned 2,607.5 cM across all 33 linkage groups. The average linkage distance between pair of markers among all linkage groups was 12.6 cM in Kosambi map units. Isoflavone content in F2 generations varied in a fashion that suggested a continuous, polygenic inheritance. Eleven markers (4 RAPD, 3 SSR, 4 AFLP) were significantly associated with isoflavone content. Only two markers, Satt419 and CTCGAG3 had F-tests that were significant at P<0.01 in F2 generation for isoflavone content. Interval mapping using the F2 data revealed only two putative QTLs for isoflavone content. The peak QTL region on linkage group 3, which was near OPAG03c, explained 14~% variation for isoflavone content. The peak QTL region on linkage group 5, which was located near OPN14 accounted for 35.3~% variation for isoflavone content. Using both Map-Maker-QTL (LOD~geq2.0) and single-factor analysis (P~leq0.05) , one marker, CTCGAG3 in linkage group 3 was associated with QTLs for isoflavone content. This information would then be used in identification of QTLs for isoflavone content with precision

Soybean is a major source of protein meal in the world. Kunitz trypsin inhibitor (KTI) protein is responsible for the inferior nutritional quality of unheated or incompletely heated soybean meal. The objective of this research was to identify RAPD markers linked to KTI protein allele using bulked segregant analysis. Cultivar Jinpumkong2 (TiTi) was crossed with C242 (titi, absence of KTI protein) and F. seeds were planted. The F1 . plants were grown in the greenhouse to produce F2 seeds. Each F2 seed from F1 . plants was analysed electrophoretically to determine the presence of the KTI protein band. The present and absent bulks contained twenty individuals each, which were selected on the basis of the KTI protein electrophoresis, respectively. Total 94 F2 individuals were constructed and 1,000 Operon random primers were used to identify RAPD primers linked to the Ti locus. The presence of KTI protein is dominant to the lack of a KTI protein and Kunitz trypsin inhibit protein band is controlled by a single locus. Four RAPD primers (OPAC12, OPAR15, OPO12, and OPC08) were linked to the Ti locus. RAPD primer OPO12 was linked to Ti locus, controlling kunitz trypsin inhibitor protein at a distance of 16.0 cM. This results may assist in study of developing fine map including Ti locus in soybean.