**2. Origin and domestication**

Flax, whose scientific name is *Linum usitatissimum* L., which translates to "extremely beneficial," comes in two primary colors: brown and yellow or golden (also known as golden linseeds) [1]. The genus Linum is a large group with ∼230 species, which subclassed to fivesubgroups including: depending on the number of chromosomes, the shape of flowers, and interspecific adaptability [2]. The section Linum contains the cultivated flax, *Linum usitatissimum*, which has 30 diploid chromosomes, along with the proposed progenitors *L. angustifolium* and L.bienne, which share homostylous rather than heterosylous flowers [3, 4].

The seed of the annual herb known as the flax plant, a member of the Linaceae family, is known as flaxseed. This herb is planted in different regions of the world from eastern Mediterranean to India, Western Asia, and the Middle East, and today, it accounts for a part of the global trade of agricultural products of some countries. There is documentation that flax was used as a fiber source in Neolithic societies. Evidence of flax fiber has been found in ancient sites in Israel and Syria [5]. Between 4500 and 4000 BC, flax was farmed in Egypt. It then spread across Switzerland and was discovered much later at Willium Hill in England [6]. Flax is thought to have been introduced to Canada by Lois Hebert, the country's first farmer, over 400 years ago [7]. Nowadays, the term "flaxseed" refers to the seeds of the flax plant when they are eaten by human, whereas the phrase "linseed" refers to the seeds of the flax plant when they are used for industrial and feed purposes [8]. The usual life cycle of a flax plant is 45–60 days of vegetative time, 15–25 days of flowering time, and 30–40 days of maturity time. It can reach a height of 12–36 meters. In accordance with the cultivar, flax can produce blue, white, pink, or violet flowers. The flax plant's mature fruit is a five-segmented dry boll or capsule. Two seeds are contained in each segment of the boll; hence, a capsule can contain up to 10 (on average 6–8) flaxseeds [9]. Seeds of flax appear in different colors depending on the amount of tannin pigments in the pigment cells of seed coat and included medium, reddish brown, and light yellow, where the brown seeds are the most abundant form of flaxseeds with higher tannin contents [10]. A commercial flaxseed strain with yellow seeds called Solin (Linola) was introduced and sold in Canada [11].

Since its cultivation began in Mesopotamia about 5000 BC, flaxseed has mostly been used for the production of cloth and paper. As mentioned, the global trade of this plant today accounts for a part of the global economy of agricultural products. Canada is the largest producer of this plant in the world with an annual production of 20 tons, and after this country, other countries such as America, China, India, and Russia are also among the main producers of this plant in the world [12]. As mentioned, the global trade of this plant today accounts for a part of the global economy of agricultural products. Canada and Russia are among the largest producers of this plant in the world, and after this country, other countries such as America, China, India, and Kazakhstan are also among the main producers of this plant in the world [13, 14].
