Effect of salinity stress on morphological, physiological, and biochemical traits of male and female plants of cannabis (Cannabis sativa L.)

Cannabis (Cannabis sativa L.) is an important dicotyledonous medicinal plants that used in many developed countries of the world. The present study was aimed to evaluate the effect of salinity stress on morphological, physiological, and biochemical traits of male and female plants of cannabis (Cannabis sativa L.). A factorial experiment was conducted using salinity stress treatments at four levels (0, 50, 75, 100 mM) and plant sex in two levels (male and female genotypes) based on a completely randomized design with three replications under greenhouse condition. The results showed that the salinity stress by plant sex interaction effects were significant for plant yield components, total phenol, antioxidant activity, total flavonoid, proline and carbohydrate (P<0.01). Increasing the salinity level significantly decreased plant height, number of leaves, plant fresh and dry weights in both sexes. But, the root weight, root length, and number of flowers increased in female plants up to 75 mM salinity. Also, increasing salinity level significantly increased secondary metabolites such as phenol, flavonoid, proline, and soluble carbohydrates in both males and female plants. However, by increasing salinity level, the amount of antioxidants increased in the females and decreased in the male plants than that for control, respectively. The sodium to potassium ratio (N/K) was considered as an index of salinity tolerance. The highest N/K ratios were observed at 75 and 100 mM salinity levels in shoot and root of the female plants, respectively. The results indicated that cannabis female plants can tolerate salinity up to 75 mM salinity level, and the female biomass was increased, but above the 75 mM level, the female plants were more sensitive than that for male plants in terms of salinity.