|Lee, Jennifer - IOWA STATE UNIVERSITY|
|Bush, Arla - FORMER USDA-ARS|
|Specht, James - UNIVERSITY OF NEBRASKA|
Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 1998
Publication Date: N/A
Interpretive Summary: Many plants contain two or more copies of each gene comprising their heredity material. Often times these genes evolve separately and no longer have the same function. In those instances where both genes retain the same functions scientists have a rare opportunity to study gene evolution. In this study the authors placed two genes controlling leaf hair mophology onto maps of soybean chromosomes. They identified large segments of three chromosomes that contain gene duplications. They also found other genes that affect the leaf hairs. This work helps scientists to understand how chromosomes have evolved and helps to explain the interactions of plant genes. Having a better understanding of gene interactions will help plant breeders improve the quality and quantity of our food sources.
Technical Abstract: Appressed pubescence genes in soybean cause hairs on the upper surface of leaves to lie flat while pubescence remains erect elsewhere on the plant. For decades this trait was believed to be controlled in soybean by duplicated single genes, Pa1 and Pa2. However, reports in the literature conflicted as to which phenotype was dominant or recessive. Two populations were developed, each approximately one hundred individuals, an each segregating for one of the appressed pubescence genes. A combination of SSRs and RFLPs were used in each of these populations to map the independent genes. Two-point analysis weakly linked Pa1 and Pa2 to separate linkage groups. Lack of strong linkage suggested the trait may not be controlled by single genes. When QTL analysis was performed one major locus and several minor loci were detected in each population. We report the mapping of the genes controlling appressed pubescence in soybean nand their placement in homologous regions. Although appressed pubescence was originally reported to be single duplicate genes, we report that it is actually a more complex phenotype with major duplicated genes and minor modifying genes. These results offer interesting implications regarding the evolution of duplicate genetic factors and the definition of qualitative traits.