Investigating the Genetic Diversity of Iranian and Foreign Cultivars of Soybean (Glycine max) using Morphological Characteristics

Soybean is a perennial and diploid plant (n2=40x2) and one of the most important plants for providing protein and fodder. Soy has been the food of Asian people, especially China, for centuries, and Chinese people consume it along with rice as their main food. The United States of America is the largest producer of soybeans and produces almost two-thirds of the world's crop. In Iran, soybeans are known as (oily beans), (Chinese beans), soja, and soybeans. By using new and high-yield varieties, the economic performance of this product can be increased. Therefore, the selection criteria of parents should be considered not only in terms of agricultural value, but also for lack of genetic differentiation. The production of new and improved cultivars can be increased with new sources of genetic diversity. Therefore, the selection criteria of parents' shares should be considered not only in terms of agricultural value, but also for lack of genetic differentiation. Therefore, understanding the genetic diversity of soybean germplasm is necessary to broaden the genetic base and use it more in the breeding program.

In this research, the number of 21 soybean varieties based on the characteristics of fresh and dry weight of whole plant, leaf fresh and dry weight, turgor index, RWC, leaf length, leaf width, leaf area, plant height, number of lateral branches, number of nodes and distance between Nodes were investigated in the form of a completely randomized experimental design in five replications in the year 1400 at the Research Institute of Environmental Sciences, University of Postgraduate Studies of Industry and Advanced Technology.

The highest amount of fresh weight (452.1 grams) was related to (F3) DM and BUNYA cultivars and the highest number of nodes (30.4) was related to NAHO, NOD-139 and ROSE cultivars. The lowest amount of fresh weight (107.22 grams) was related to BRAGG variety and the lowest number of knots (8.8) was related to BRAGG variety. The highest number of lateral branches (9) was related to the variety KATOL and the lowest distance of the number of lateral branches (2) was related to the variety S355-4. The highest relative amount of water (RWC) (1.77) was related to SALAND and DM(F3) varieties and the lowest relative amount of water (RWC) (48.4) was related to FORREST variety.

Considering that the DM(F3) variety has the highest biomass (wet weight and dry weight), relative water index content (RWC) and turgor index, it can be used as a suitable parent in crossbreeding projects for soybean genetic improvement.