Evaluation of Some Physical Properties of Sixteen Iranian Indigenous Barberry Genotypes

Barberries are a broad class of spiny evergreen or deciduous shrubs belonging to the Berberidaceae family. They are of great importance due to their different parts' nutritional and medicinal properties and their ornamental applications. Genus Berberis, the biggest genus in Berberidaceae, includes more than 660 species. Barberry grows in Asia and Europe and has been used extensively as a medicinal plant in traditional medicine. In Iranian traditional medicine, several properties, such as antibacterial, antipyretic, antipruritic and antiarrhythmic, have been reported with unknown mechanisms of action. Incredible structural diversity among barberries' active components makes them a valuable source of novel therapeutic compounds. Seedless barberry (Berberis integerrima 'Asperma') is one of Iran's valuable indigenous medicinal plants. Common asexual propagation of this plant over the years and consequently low genetic diversity in populations of the seedless barberry restricts selection outcomes in breeding programs. Utilizing the indigenous wild genotypes of the barberry genus, which are easily able to cross-pollinate, is one of the best methods to increase genetic diversity. Accordingly, several wild seedy barberry genotypes were identified from all over Iran, collected and established in a collection in Mashhad; then, 16 genotypes were selected and their physical properties were studied. 
In this study, ripe fruits of sixteen unique genotypes (i.e., Iranian seedless barberry and fifteen seedy genotypes) were harvested in October- November 2015 and kept in a refrigerator in order to measure some of their physical properties in fresh fruits (berry dimension, 100-berry weight, juice content and color indices). For other properties, fruits were dried at room temperature. Fruit cluster length was measured by means of a ruler, the number of berries/cluster and the number of set/aborted seeds in berry by counting, berry dimensions by a digital caliper, weight of fresh and dried 100-berry, percentage of pulp and seed as well as fruit juice content by a scale with 0.001 accuracy. Moisture content was determined using an oven with 75 ºC temperature for 48 hours. Color indices, including L*, a* and b*, were measured using a portable colorimeter (Konica Minolta Chroma Meters CR-410). This study was performed using a completely randomized design with three replications. Data were analyzed by Minitab software version 16 using analysis of variance (ANOVA), and differences among means were determined for significance at p<0.05 using the Bonferroni test.
The results indicated significant differences among genotypes. Based on the results, cluster length ranged between 1.67cm (code 5-3) and 6.29 cm (code 10-1); moisture content was between 8.20% and 11.84% in genotypes 8-3 and 13-2, respectively. The fruit juice content range of the studied genotypes was between 51.22% and 71.87%. Genotype 2-1 had the highest dimension values and the highest 100-berry fresh weight (30.72g) and dry weight (10.00g) fruits. The lowest weights of 100-berry were related to 14-1 and seedless barberry. Genotypes 5-2 had the highest pulp percentage (98.17%) and the lowest seed percentage (1.50%) and 10-1 had the lowest pulp percentage (51.93%) and the highest seed percentage (48.07%). The highest number of set seeds (1.73) and the lowest number of aborted seeds (zero) were found in (10-1) and (14-2), respectively. Based on the results, seedless barberry had the lowest number of set seeds (0.00) and the highest number of aborted seeds (3.27). Regarding fruit color indices, genotypes showed significant variability from orange to brown and dark blue. Color indices L*, a* and b* ranged (from 22.83 to 38.13), (2.31 to 37.76) and (1.18 to 2.28), respectively.   
In conclusion, it can be said that all genotypes have considerable variability in fruit traits (color, fruit dimensions, pulp/seed percentage, moisture content, etc.). Based on the result of this study, genotype 5-2 was the most similar genotype to seedless barberry. The seedless barberry populations have low genetic diversity due to asexual propagation through suckers over many years. Indigenous genotypes can be a valuable genetic resource for future breeding programs to improve the quantitative and qualitative characteristics of seedless barberry and introduce new cultivars of seedless barberry with different colors and consequently different nutritional- medicinal properties.