A Study on the Yield and Related Traits of some Forage Low-Tannin Faba bean (Vicia faba L.) Genotypes

Background: The faba bean (Vicia faba L.) is considered one of the important legumes and is cultivated as a source of cheap protein.This plant is very suitable for agriculture due to having suitable agricultural characteristics, including nitrogen fixation and the possibility of being placed in crop rotation with fall crops, especially cereals.Bean plant fodder can also be ensiled pure or mixed with cereal plants.Therefore, studies on the genetic diversity of this plant help breeders to identify the genetic potential and capacity of different cultivars, as well as to find out the relationship between different traits with fodder and seed yield and determine the most important morphological characteristics affecting yield.Methods: To investigate the yield and related traits of some low-tannin fodder genotypes of faba bean, an experiment was performed based on a randomized complete block design with three replications in the research field of the Gharakheyl Agricultural Research Station (Mazandaran Agricultural and Natural Resources Research and Education Center) in 2022.The treatments included 11 bean cultivars (nine low-tannin bean lines from ICARDA along with a low-tannin control variety (Mahta) and a tannin-rich control (Shadan) from Iran).Each genotype was cultivated in six lines of 6 meters.The distance between the rows was 60 cm, and the distance between the plants on the row was 8 cm.The seeds were sown by hand at a depth of 5 cm in the soil in November.From the time of planting to harvesting during agricultural operations, necessary notes were taken at different stages of growth and development.Analysis of variance (ANOVA) was performed on recorded yield data and yield components, and the mean of treatments was compared with the least significant difference (LSD) method using SAS 9.0 software.Bean genotypes were grouped using cluster analysis based on Euclidean distance and Ward's method.The correlation between traits was calculated by Pearson's method and stepwise regression analysis using SPSS 18 software.Results: The results of ANOVA for the data showed a significant difference between the broad bean cultivars in terms of leaf dry weight, stem dry weight, days to germination, fodder dry weight, seed yield, leaf fresh weight, pod dry weight, fodder fresh weight, and the harvest index.The mean comparison of traits showed that the Mahta cultivar produced the highest value of grain yield (5.24 tons/ha) and the highest value of fodder dry weight (8.19 tons/ha).The highest fodder fresh weight belonged to the FLIP03-07FB cultivar at the rate of 35.76 tons/ha, which was not significantly different from the Mahta and s2008-033 cultivars.The highest values of stem dry weight and pod dry weight belonged to the Mahta genotype (2.69 and 3.73 tons/ha, respectively), and the highest leaf fresh and dry weights belonged to the s2008-033 genotype (7.20 and 1.78 tons/ha, respectively).Cluster analysis placed the studied genotypes into three groups.The s2008-033 genotype was included in the first group.This genotype showed the highest values in most of the studied traits, and in some traits such as the harvest index, fodder fresh weight, and grain yield, there were no significant differences with the highest values of the genotypes.In the second group, there were five genotypes WRB1-5, WRB1-3, Shadan, s2009-167, and Mahta, and except for two harvest index and grain yield traits with high values, they were in an average condition in