We have identified an albino mutant in the plant Brassica rapa. This recessive mutation could provide insights into the photosynthetic pathways of all plants. Previously the mutation was mapped to chromosome 10 of Brassica rapa. To narrow down the chromosomal region containing the albino mutation, we grew a segregating population of plants. DNA was extracted from albino and wildtype (green) plants and genotyped using PCR markers on chromosome 10. The genotype detected using the INDEL2 marker perfectly predicted whether a plant was albino or WT. This indicates that the INDEL2 marker is tightly linked to the albino mutation. INDEL2 is near the gene PDX2 and we detected a single nucleotide change near the PDX2 gene that is only found in albino plants. It is possible that this mutation affects the expression of PDX2 and is the cause of the albino phenotype. PDX2 is involved in vitamin B6 synthesis and it is unclear how altering vitamin metabolism could affect photosynthesis
