Combination of Salinity and Sodicity Levels Facilitates Screening of Medicinal Crop Linseed (Linum Usitatissium)

Salts lessen germination, delay emergence, and retard seedling growth of linseed (Linum Usitatissimum L.). In this research experiment, we designed to find out the effects of (4 dSm-1+ 13.5 (mmol L-1)1/2, 5 dSm-1 + 25 (mmol L-1)1/2 , 5 dSm-1 + 30 (mmol L-1)1/2, 10 dSm-1 + 25 (mmol L-1)1/2 and 10 dSm-1 + 30 (mmol L-1)1/2) on biomass yield of linseed to screen against salinity tolerance using biomass yield characteristic. Highest biomass yield (45.53 gpot-1) was attained by 4 dSm-1+ 13.5 (mmol L-1)1/2 treatment. Biomass yield was decreased as well as the toxicity of salts was increased. Lowest biomass yield (27.75 gpot-1) was produced at 10 dSm-1 + 30 (mmol L-1)1/2. 5 dSm-1 + 25 (mmol L-1)1/2 treatment performed better results i.e. the least reduction % over control (20.25). Salinitysodicity showed serious effect on the growth reduction from 20.25% to39.05%. This reduction gap was affected by the negative effect of salinity and sodicity on Linseed growth. Salinitysodicity showed severe impact on the growth reduction from 20.25 to39.05%. Based on the findings, linseed (Linum usitatissimum L.) was able to grow the highest at 4 dSm-1+ 13.5 (mmol L-1)1/2 treatment.


Introduction
Linseed (Linum usitatissimum L.) is a cool temperate annual herb with erect stems. Although there are several utilization purposes, it is cultivated commercially for its seed, which is processed into oil and a high protein stock feed after oil extraction Sankari [1][2][3] and for its fibers, which are made into linen and other cloths El-Nagdy et al. [4]. In addition, linseed varieties with oils suitable for culinary use are available Hosseinian et al. [5]. Seedling establishment is generally slow and seedlings have poor competitive ability. In arid and semi-arid regions where rainfall is insufficient to leach salts out of the root zone, the salinity is a major problem which limits plant growth Khajeh-Hosseini et al. [6], since evaporation tends to exceed rainfall Kaya et al. [7]. Out of 20.2 million hectares of cultivated land in Pakistan, 6.8 million hectares are affected with some degree of salinity Anon [8]. The main approach of testing the linseed growth for salinity tolerance is growing it on the salt affected soils. Several researches on the classification of crop plants for salinity have been performed using various criteria such as reduction in plant growth Bassil and Kaffka [9][10][11], water stress day index Katerji et al. [12], biochemical activities Johnson et al. [13], ion balance Alian et al. [4,15], and yield reduction Natarajan et al. [16]. Further, the use of landraces for fibre flax breeding was described by Zhuchenko and Rozhmina [19]. Such studies have proven to be useful tools for efficiently preserving and using flax germplasm collections Diederichsen [17,20,21]. These primary evaluations of flax germplasm collections were followed by numerous secondary evaluations for different characters related to tolerance to biotic and abiotic stress factors Brutch [19,22] with recent focus of germplasm screening on monogenic traits, such as disease resistances Rashid [23]. Some work on the effect of salinity on germination and growth of medicinal plants include Linum usitatissimum, Trigonella foenum-graecum Ashraf et al. [10,[24][25][26][27][28][29][30] Ricinus communis Raghavaiah [31]. It appears that little information is available regarding the effect of salinity on the growth and productivity of medicinal plants.
Lepidium sativum L., Linum usitatissimum L., Plantago ovata Forssk and Trigonella foenum-graecum L. have been evaluated and proved to be moderately salt tolerant at germination and seedling growth stage Muhammad & Hussain [32]. Supplies of good quality water are falling short of demand for intensive irrigated agriculture in many arid and semi-arid countries due to increased pressures to produce more for the growing population as well as competition from urban, industrial and environmental sectors. Therefore, available freshwater supplies need to be used more efficiently. In addition, reliance on saline waters generated by irrigated agriculture or pumped from aquifers seems inevitable for irrigation Bouwer [33] Qadir et al. The same applies to salt-affected soils, which occur on 831.106 ha Beltra´n and Manzur [34]. Sodicity causes structural problems in soils created by physical processes such as slaking, swelling and dispersion of clay; as well as conditions that may cause surface crusting and hard setting Quirk [35].
Several major irrigation schemes throughout the world have suffered from the problems of salinity Gupta and Abrol [36][37][38]. Generally, the worst salinity impacts occur where farming communities are relatively poor and face economic difficulties.
In severe cases, salinization causes occupational or geographic shifting of the affected communities, with the male population seeking alternate off-farm income opportunities Abdel- [1,40]. As the agricultural use of salt-affected land and saline water resources increases, their sustainable use for food and feed production will become a more serious issue Suarez [41], In the present scenario human use of poorquality irrigation systems is a major concern for scientists around the world. Therefore, apart from the need for proper irrigation practices a concerted effort to understand the effect of salinity on plants, development of genetically engineered crop varieties and superior tolerant cultivars are essential to combat the world's salinization problems Tester and Davenport [43]. (mmol L-1)1/2). Completely randomized deign was applied with three repeats. Data on biomass yield were collected. Collected data were statistically analysed and means were compared by LSD at 5 % Montgomery [44].

Results and Discussions
Salinity adversely reduces the overall productivity of plants Kurt and Bozkurt [2]. Salinity leads to delayed germination and emergence, low seedling survival, irregular crop stand and lower yield due to abnormal morphological, physiological and biochemical changes Munns [15]; Muhammad and Hussain [31].