Evaluation of Polyphenols Synthesized in Mature Seeds of Common Bean (Phaseolus vulgaris L.) Advanced Mutant Lines.

This study aimed to investigate the availability of flavonoids, anthocyanins, and phenolic acids in mutant bean seeds, focusing on M7 mutant lines, and their corresponding initial and local cultivars. HPLC-DAD-MS/MS and HPLC-MS/MS were used to analyze twenty-eight genotypes of common bean. The obtained results suggest that the mutations resulted in four newly synthesized anthocyanins in the mutant bean seeds, namely, delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, pelargonidin 3-O-glucoside, and petunidin 3-O-glucoside, in 20 accessions with colored seed shapes out of the total of 28. Importantly, the initial cultivar with white seeds, as well as the mutant white seeds, did not contain anthocyanins. The mutant lines were classified into groups based on their colors as novel qualitative characteristics. Five phenolic acids were further quantified: ferulic, p-coumaric, caffeic, sinapic, and traces of chlorogenic acids. Flavonoids were represented by epicatechin, quercetin, and luteolin, and their concentrations in the mutant genotypes were several-fold superior compared to those of the initial cultivar. All mutant lines exhibited higher concentrations of phenolic acids and flavonoids. These findings contribute to the understanding of the genetics and biochemistry of phenolic accumulation and anthocyanin production in common bean seeds, which is relevant to health benefits and might have implications for common bean breeding programs and food security efforts.

Phaseolus vulgaris mutants reveal variation in the nuclear genome.

Phaseolus vulgaris L. (common bean) is an essential source of proteins in the human diet worldwide. Bean breeding programs to increase genetic diversity based on induced mutagenesis have a long tradition in Bulgaria. Common bean varieties with high productivity, wide environmental adaptability, good nutritional properties, and improved disease resistance have been successfully developed. In this study, we aimed to investigate selected nuclear genome features, such as the genome size, the number and chromosomal distribution of 5S and 35S rDNA loci by using the fluorescence in situ hybridization (FISH), as well as the level of DNA damage in some local Bulgarian accessions and mutants of P. vulgaris. Flow cytometry analyses revealed no significant differences in genome size between analyzed lines except for one of the analyzed mutants, M19. The value of genome size 2C DNA is about 1.37 pg2C -1 for all lines, whereas it is 1.42 pg2C-1 for M19. The chromosome number remains the same (2n=22) for all analyzed lines. Results of FISH analyses showed that the number of 5S rDNA was stable among accessions and mutant lines (four loci), while the number of 35S rDNA loci was shown as highly polymorphic, varying between ten and sixteen, and displaying differences in the size and location of 35S rDNA loci between analyzed genotypes. The cell cycle profile was different for the analyzed genotypes. The results revealed that wide variation in genome organization and size as well as DNA damage characterizes the analyzed genetic resources of the common bean.

Green Assessment of Phenolic Acid Composition and Antioxidant Capacity of Advanced Potato Mutant Lines through UPLC-qTOF-MS/MS Quantification.

Potatoes are one of the most consumed crops worldwide. They contain a high amount of bioactive compounds such as phenolic compounds and vitamins with important antioxidant activities, which makes this crop of high biological value for human health. The goal of this research was to biochemically evaluate polyphenol levels and antioxidant capacities in parent and control genotypes compared to advanced mutant potato lines in the M1V8 generation. This will reveal the genetic changes that result from induced mutagenesis. The quantified compounds and the evaluated antioxidant activity boost the health benefits of consuming the improved mutant potatoes. In the present study, the phenolic composition and antioxidant activity of eighteen mutant and initial potato genotypes were analyzed by UPLC-qTOF-MS/MS and the ORAC method, respectively. In each of the hybrid combinations, mutant lines with an improved phenolic compound profile were observed. Representative samples from the third hybrid combination had notable increases in phenolic compound concentrations, as well as the presence of metabolites not found in the parental lines. With one exception, the remaining nine mutants showed significantly higher antioxidant capacities. The results will be used in future potato breeding programs, with participation of the valuable mutant lines containing new phenolic substances not present in the initial genotypes.

Metabolic Profiling of Bulgarian Potato Cultivars.

Potatoes (Solanum tuberosum L.) are the fourth most economically important crop in the world. They have a short period of vegetation and are an excellent source of carbohydrates, amino acids, vitamins, organic acids, minerals and phenolics as antioxidant substances. Potato can be a major dietary source of various bioactive compounds. In this study, we applied gas chromatography coupled with mass spectrometry (GC-MS) metabolite profiling to classify eight Bulgarian potato cultivars bred in the Maritsa Vegetable Crops Research Institute (VCRI), Plovdiv, according to their metabolite contents. Altogether, we determine their flavonoids/phenolics to evaluate their nutritive quality for the breeding program with the target of determining strong health-promoting compounds. The "Kalina" cultivar is highlighted as the best one with the highest number of metabolites, containing 14 out of the 26 evaluated; it was selected as the highest-quality cultivar, compared with the other seven cultivars studied. According to the grouping of the cultivars in principal component analysis PCA, their positive distribution is explained mainly by them having the highest contents of aminobutyric and isocitric acids, methionine and alanine and lower levels of fumaric acid, pyroglutamic acid and glycine, in contrast to the cultivars distributed negatively, which had high contents of carbohydrates and relatively low contents of most of the amino acids. The highest number of amino acids was found in the cultivar "Kalina", followed by "Perun" and "Bor". The highest number of carbohydrates was found in "Pavelsko" and "Iverce", while the prominent accumulation of organic acids was found in "Kalina", "Bor" and "Rozhen". The highest number of flavonoids in the flesh of the tubers was found in the cultivars "Nadezhda" and "Pavelsko", followed by "Bor". The highest ratio of flavonoids/phenolics in the flesh was found in "Pavelsko" and in "Nadezhda", followed by "Iverce".

Mutation Associated with Orange Fruit Color Increases Concentrations of ß-Carotene in a Sweet Pepper Variety (Capsicum annuum L.).

Pepper is the second most important vegetable crop in Bulgarian agriculture and has become the subject of extensive breeding programs that frequently employ induced mutagenesis. The success of breeding programs can be enhanced by the efficient and integral application of different biochemical and molecular methods to characterize specific mutant alleles. On the other hand, identifying new cost-effective methods is important under a limited-resources environment. In this paper we compare the levels of five health-related carotenoid compounds of fruits (α-carotene, ß-carotene, lutein, ß-cryptoxanthin, zeaxanthin) between a mutant variety Oranzheva kapia (possessing high ß-carotene concentration) and a corresponding initial pepper variety Pazardzhishka kapia 794. Both varieties are intended for fresh consumption. Pepper is a major natural source of ß-carotene. It was observed that fruit at both commercial and botanical maturity from mutant variety had greater α-carotene and ß-carotene concentrations to the initial variety (7.49 and 1.94 times higher, respectively) meaning that the mutant was superior in fruit quality to the initial genotype. Two hydroxylase enzymes, converting α- and ß-carotene to lutein and zeaxanthin, respectively, are known to exist in pepper and are encoded by two genes on chromosomes 3 and 6-CrtZchr03 and CrtZchr06. The molecular characterization of the mutant variety through locus-specific Polymerase chain reaction amplification, gene cloning and sequencing as well as expression was performed. Our results suggest that the increased ß-carotene accumulation in the mutant variety Oranzheva kapia results from a biosynthetic pathway breakdown due to deletion of CrtZchr03 gene.

Mutation increasing ß-carotene concentrations does not adversely affect concentrations of essential mineral elements in pepper fruit.

Vitamin and mineral deficiencies are prevalent in human populations throughout the world. Vitamin A deficiency affects hundreds of millions of pre-school age children in low income countries. Fruits of pepper (Capsicum annuum L.) can be a major dietary source of precursors to Vitamin A biosynthesis, such as ß-carotene. Recently, pepper breeding programs have introduced the orange-fruited (of) trait of the mutant variety Oranzheva kapiya, which is associated with high fruit ß-carotene concentrations, to the mutant variety Albena. In this manuscript, concentrations of ß-carotene and mineral elements (magnesium, phosphorus, sulphur, potassium, zinc, calcium, manganese, iron and copper) were compared in fruit from P31, a red-fruited genotype derived from the variety Albena, and M38, a genotype developed by transferring the orange-fruited mutation (of) into Albena. It was observed that fruit from M38 plants had greater ß-carotene concentration at both commercial and botanical maturity (4.9 and 52.7 mg / kg fresh weight, respectively) than fruit from P31 plants (2.3 and 30.1 mg / kg fresh weight, respectively). The mutation producing high ß-carotene concentrations in pepper fruits had no detrimental effect on the concentrations of mineral elements required for human nutrition.