Genetic Analysis And Mapping Of Soybean Lipoxygenase-null Mutation Gene

The soybean lipoxygenase(EC1.13.11.12; Loxs) mainly exists in the soybean seed and includes Loxl, Lox2, and Lox3 that is separately controlled by Lx₁, Lx₂ and Lx₃. Its catalysis produce beany flavor and saline flavor that make itself a important anti-nutrition factor which affects soybean edible quality, preserve quality and process quality. Mutantgene------lx₁, lx₂, and lx₃ can make beany flavor reduce or vanish. Therefore, the mappingto three genes with the molecular mark can assist foreground selection, further, accelerate the cultivation of the full Loxs-null and excellent soybean lines.Five crosses are cultivated by Hebei Oil Crops Institute. F₂ seeds were detected seed by seed by the improved IEF-PAGE (Isoelectic focusing poly-acrylamide gelelectrophoresis) for identifying their phenotypes. Aim of the study is determining the inheritance mode of three pairs allele, screening nearer SSR markers of Lx₁/lx₁ and Lx₂/lx₂, further, finely mapping them, and finishing preliminary mapping of Lx₃/lx₃. The main results are summarized as follows:As Lox3, Loxl have a, b subunit in cross 0124,0139,0155, and 0134. When Loxl is loss, 1a is loss, but 1b reserve and has no change. Cross 0129 have only one unit. When Lox2 is loss, Loxl completely disappear. As Lox3 is loss, 3b vanishes and 3a doesn't change that is contrary with Lox1.When Lox2 is loss, Lox2 doesn't completely disappear, and Loxl behaves differently in different crosses: la is near from lb in cross 0139, 0155, and 0134. As Lox2 is absent, lb is invariable and 1a upwardly move for a distance; 1a is far from 1b in cross 0124.As Lox2 is absent, both la and lb are invariable. Loxl entirely move in cross 0129.Lx1 (Lx₃) is dominant to lx₁ (Ix₃); Lx₂/lx₂ is one pair co-dominant alleles. The separation of Lx₁ and Lx₃,Lx₂ and Lx₃ conforms to 9:3:3:1, Lx₁ and Lx₃, Lx₂ and Lx₃ are in different linkage group.Lx doesn't locate in linkage groups E and I where QTLs of the soybean seed protein mainly concentrate; EST pBLT002 in linkage group I just resemble...