Introduction: Beans (Phaseolus vulgaris L.) are a plant in the legume family (Fabaceae). Beans contain polyphenolic compounds, anthocyanins and flavonoids that are nutritionally and pharmacologically important, have genetic diversity, and are the most valuable and economical part of global biodiversity, which is crucial for future global production. Allelic diversity of MYB genes is important in the control of pigment and anthocyanins. Bean seed dye coating is one of the most important traits in consumer marketing. Recent studies show that bean seeds have a pigmented coating, higher anthocyanins that have anti-cancer and antioxidant properties. Increasing the consumption of legumes in the diet and antioxidants requires the study of the amount and genetics of genes that control bean seed coat.
Materials and Methods: 12 bean cultivars of different genera were collected from different regions of Ilam province and Ilam University Gene Bank and in 1397 in the greenhouse of Ilam University were planted in a randomized complete block design with 3 replications. Leaf sampling was performed in 2 to 3 leaf stage. Giusti and Wrolstad (2001) methods were used to measure anthocyanins. Mean comparisons were performed using Duncan test at 5% probability level using SAS 1.9 software. Genomic DNA was extracted by Doyle (1987) method. PCR reaction was performed in a volume of 25 μl. BLAST method was used to check the accuracy of the sequences obtained with the samples in NCBI. BioEdit, CLC sequencer Viewwer6, Geneious and MEGA5.2 were also used for other bioinformatics analyzes.
Results and Discussion: Examination of 12 bean genotypes showed that there was a significant difference between different bean genotypes in terms of anthocyanin trait. In terms of anthocyanin trait, cultivar 6 (black bean) was superior to all cultivars. Examples of common eye beans are 1 and 2. The reason for this difference is that the mutant eyebrow sample has more coverage with black areas. The dark color of the seed coat of this cultivar indicates more anthocyanin than two normal ocular samples. It should be noted that black seed dye is directly related to anthocyanins. Molecular analysis of MYB and AF genes showed that MYB gene was amplified in samples of ordinary ocular beans 1, 2, mutant and bride beans, while AF gene was amplified only in ocular samples 1, 2 and mutant beans. Bioinformatics analyzes showed that the sequences of these two genes are very similar to the samples in NCBI, so that in the AF gene, two new alleles were identified compared to the sequences introduced to control pigment coverage in beans. Also, the phylogenetic diagram of the samples using the UPGMA method showed that the samples could be separated based on the color of the grain coating.
Conclusions: Seed black color is controlled by anthocyanin biosynthesis by genes related to MYB transcription factor, which in addition to affecting the color of the seed coat, which has a more attractive appearance than ordinary ocular cultivars, also contains more anthocyanin. Therefore, due to the presence of MYB and AF genes that are involved in the synthesis of anthocyanins, has made the bean product more attractive and marketable, which have higher levels of anthocyanins and can be given special attention in the diet. According to the results of this study, it can be said that Mutant ocular cultivar due to more anthocyanins and more attractive appearance compared to other ocular bean cultivars can replace the common cultivars of this type of bean and is a good option for further studies and introduction to farmers in the future.