Primary Mapping On Low Boron Tolerance Gene In Arabidopsis

With the completion of the model plant Arabidopsis thaliana genome sequencing in2000, study cloning genes for low boron tolerance in Arabidopsis will benefit the understanding of boron (B) tolerance and genetic improvement of B nutrient traits in crops. In this study, a mutant Lbt with the phenotype of low-B tolerance was screemed in Arabidopsis. Lbt gene was mapped to a region with linkage marker s01m04-1-440on chromosome Ⅳ. The main results were shown as following:1. Genetic analysis of mutant Lbt in ArabidopsisLow-B tolerance mutant was crossed with low-B sensitivity RI line RI1909to construct a F2population for the first mapping. According to the genetic analysis of F1and F2phenotypes under low B stress, it is comfirmed that the mutant is caused by single recessive gene mutantion.2. Constructing the genetic linkage mapA genetic linkage map was developped with the F2population by SSR and AFLP molecular marker using JionMap4.0, which included206markers (SSR markers and AFLP markers). The map had4linkage groups with an average length of3.48cM and covered a total of317.14cM.3. Primary mapping for low-B tolerance gene in ArabidopsisAs a qualitative trait, Lbt gene was located near the molecular marker s01m04-1-440on chromosome Ⅳ. As a quantative trait, the target QTL was also detected on chromosome Ⅳ. Further research about the sequencing of linkage markers was confirmed that the result was correct. However, there are no polymorphisms markers between two parents in the target region, which does not benefit fine mapping further.