s.m. mirmiran

The presence of plant species in each region is influenced by the environmental and biological factors of that region. Therefore, to establish the coverage and distribution of plant species and the factors affecting their growth and development, it is necessary to research the ecological requirements of the species and the environmental characteristics of the studied area. This information can be used for planning and implementing basic management plans for the restoration and modification of habitats and the protection of water and soil resources. This research aims to identify the habitat conditions of Prunus scoparia (Spach) C.K.Schneid.

This research was conducted in Razavi and South Khorasan provinces across six habitats: Qaen, Bajestan, Ferdows, Khaf, Bardaskan, and Sarayan. In each representative area, a site was selected, and three transects of 100 meters were established, each with a distance of 20 meters. Along each transect, 10 plots of four square meters were established (a total of 30 plots in each habitat). In each plot, the percentage of canopy cover, density of a single plant species, litter percentage, and bare soil percentage with pebbles were determined. Additionally, for each habitat, two soil samples were collected from the beginning and end of each transect, resulting in a total of 36 soil samples. The soil texture, electrical conductivity, saturation moisture, pH, total nitrogen, phosphorus, potassium, sodium, calcium, magnesium, chlorine, lime, organic carbon, and organic matter were analyzed using conventional methods. After collecting all the climate, soil, topography, and vegetation data related to the six habitats of wild almond in Khorasan province, the scope of the ecological expansion of the studied species based on the studied factors was first determined. Then, using principal component analysis (PCA), the environmental factors affecting the distribution of wild almond species were identified.

The results showed that the Ferdows habitat exhibited the highest percentage of vegetation cover, while Bardaskan had the highest canopy cover percentage, density, and mean height for wild almond. The lowest percentage of vegetation cover, canopy cover, and density of the species was found in Bajestan, and the lowest mean height of the species was recorded in Khaf. Soil physical properties, such as soil texture components including the percentage of clay, sand, slope, and calcium, showed the largest contribution to explaining the variance of axis 1 and are more important than soil chemical properties. In the Bardaskan habitat, calcium and slope had a positive effect on the distribution of wild almond, but the percentage of clay showed a negative effect. Organic carbon is effective in the species distribution in this habitat. Altitude and rainfall are effective in the distribution of wild almond in Qaen. In general, clay, calcium, slope, sand, and maximum temperature play the biggest role in the distribution of the species in all the studied areas. There are many variations in the soil properties of the habitats. The two habitats of Khaf and Bardaskan are similar to each other in terms of soil characteristics, and wild almond is distributed in these habitats with high slopes and a high percentage of sand and calcium. In general, considering all the climatic, soil, and altitude characteristics, wild almond habitats are placed in three clusters. Khaf and Bardaskan habitats were in the first group, Sarayan and Bajestan habitats were in the second group, and Qaen and Ferdows habitats were in the third group.

The range of distribution of wild almond in the studied areas was around 1480 to 1700 meters above sea level, generally in southern directions, with slopes ranging from 10% to 66%, and annual rainfall between 130 to 187 mm. The soil texture of the habitats is loamy to sandy-loam, and the soil is non-saline. Among the studied factors, soil calcium, soil texture, slope percentage, and maximum temperature had the most significant effects on the distribution of wild almond in the studied areas. Considering the distribution of this plant in a wide range of environmental conditions, including climate, physiography, and soil, and its positive effect on controlling soil erosion on slopes, it is recommended to cultivate this species in degraded mountainous areas.

Aiming to understand the habitat conditions of Prunus chorassanica (Pojark.) A.E.Murray as an endemic shrub species of Iran, this study was conducted in Khorasan Razavi Province. To measure the canopy coverage percentage and density of plant species in the three studied sites located in Dargaz County, three transects of 100 meters were established. Along each transect, a 5 m2 plot was established every ten meters and sampling was done by systematic random method. Also, the ecological conditions of the species growth and distribution; including climate, topography and edaphic characteristics of the sites were investigated. The canopy cover of P. chorassanica in the three studied sites were 7.87 to 11.7% and the density were between 50 to 75 tree per ha. In the shrub's sites, 34, 38.5 and 27.5% of the soil was sand, silt and clay and the desired soil texture was loam. The average pH and electrical conductivity of the soil are equal to 7.73 and 0.8 dS/m, respectively. This species grows and spreads in altitudes above 2000 meters and on slopes between 30 and 55%, generally in the northern direction. Considering the value of this species, in the form of action for protection outside the main site, it is necessary to collect the seeds of this species and store them in the Iran's Natural Resources Gene Bank. Also, it should be planted in the National Botanical Garden of Iran so that, if necessary, it is possible to revive its population in nature.

Salinity tolerant of 24 lentil genotypes was investigated in a split-plot based on a randomized complete blocks design with three replications. Salinity levels (0.5, 12, and 16 dS m-1) were arranged as the main plot and lentil genotypes as the subplot. Results indicated that salinity levels of 12 and 16 dS m-1 reduced the survival percentage of all genotypes compared to control. MLC57, MLC73, MLC94, MLC104, and MLC108 genotypes were not able to tolerate the 16 dS m-1 salinity level. Morphological traits were affected by salinity stress as plant height, number of branches per plant, dry weight, and leaf survival percentage in most genotypes were decreased. Compared to control, the lowest reductions of plant height, number of branches per plant, plant dry weight, and leaf survival percentage were observed at salinity level of 16 dS m-1 in MLC13, MLC120, MLC4, and MLC12 genotypes, respectively. Also the lowest increase in Na+ (5.5 times) and the highest increase in Ca2+ (4 times) were observed at salinity level of 16 dS m-1, in MLC108 and MLC78, respectively. In other words, these genotypes were able to reduce the adverse effects of increased NaCl in higher salinity levels. Principal component analysis (PCA) showed that all genotypes of the first group (MLC6, MLC12, MLC26, MLC117, MLC120, and MLC178) were superior for most traits as compared to the total mean. Generally, it could be concluded that this group of genotypes has a better survival percentage and growth characteristics in salinity conditions, which may be used to select salinity tolerant lentil genotypes in subsequent studies.

Cultivation of medicinal plants, such as fenugreek, is important for producing healthy food and preparing raw materials for herbal medicines. Determining the appropriate planting date and tolerance of fenugreek to low temperatures can help to gain more economic yield. The effects of cold and fall planting on the Iranian fenugreek (Trigonella foenum-graceum L.) landraces were evaluated under controlled and field conditions in two years (2013-2015). Ten fenugreek landraces including Azari, Ardestan, Tall, Dwarf, Shiraz, Shirvan, Mashhad, Neyshabour, Hamedan, and Hendi landraces were planted on five planting dates (September 14, October 15, and November 14 in 2013; March 6 and April 4 in 2014). These landraces were also planted on four planting dates (September and October in 2013; March and April in 2014) in pots and were transferred to a thermogradient freezer to apply frost temperatures (-6oC, -9oC, -12oC, and -15oC). Four landraces including Dwarf, Shirvan, Mashhad, Neyshabour landraces were planted on five planting dates similar to the first year in the second year. Shirvan landrace showed more tolerance to freezing temperatures. Evaluation of survival rate showed that the controlled grown landraces had higher survival rates than the field-grown landraces. Mashhad (55%) and Shirvan (44%) had the highest and lowest yield reduction rates as a result of delaying the planting date from September to April. The branch number/plant in the first year of the field experiment and 1000-seed weight (TSW) in the second year had the most important impact on the seed yield. The most suitable sowing dates for the highest seed yield were October 15 and November 14. Shirvan landrace had the highest seed yield in all the planting dates in both years, and it can be recommended for cultivation in the regions.

To study freezing tolerance (-13, -15 and -18°C) of 40 lentil (Lens culinaris Medik.) genotypes, a factorial experiment in completely randomized design was carried out at the Research Center of Plant Science, Ferdowsi University of Mashhad, Mashhad, Iran, in 2017-2018. Significant differences observed between genotypes for survival percentage after freezing stress and chlorophyll a, carotenoids, anthocyanins, soluble carbohydrates, proline, malondialdehyde (MDA), phenol, protein, DPPH, ascorbate peroxidase and peroxidase before freezing stress. Stepwise regression analysis showed that chlorophyll b had the most positive effect and protein, and MDA had the most negative effect on survival percentage. Cluster analysis grouped genotypes into five clusters. For most of the studied traits, genotypes in clusters 4 and 5 were greater than average of all genotypes as well as genotypes in other clusters. In clusters 4, anthocyanins, protein, MDA, phenol, proline, ascorbate peroxidase and peroxidase contents were higher than other clusters. Survival percentage, chlorophyll b, carotenoids, total pigments, and DPPH of cluster 5 were higher than the other clusters. Principal component analysis showed that MLC469, MLC458, MLC409, MLC74, MLC84, MLC169, MLC394, MLC95, MLC17, MLC163 and MLC303 for antioxidant capacity and metabolites, and MLC70, MLC410, MLC47, MLC31, MLC91, MLC8, MLC286, MLC407, MLC472, MLC61, MLC83 and MLC334 for photosynthetic pigment capacity were more suitable than the other genotypes. It can be concluded that these attributes are very important in predicting, before cold stress, the effect of cold stress on survival percentage of lentil genotypes.

To study freezing tolerance of 40 genotypes of lentil (Lens culinaris Medik.) an experiment as factorial arrangements in completely randomized design with three replications was carried out at the research center for plant science, Ferdowsi University of Mashhad, Mashhad, Iran, in 2017-2018. Genotypes were exposed to three levels of freezing temperatures (-13, -15 and -18 °C). The results showed that at -13, -15 and -18 °C temperature levels, 100, 93 and 30 percent of genotypes had no significant difference with their maximum survival (100%), respectively. Only three genotypes MLC12, MLC17 and MLC95 were able to maintain 100% survival at all three freezing temperature levels. The lowest temperatures reducing 50% of leaf area (RLAT50) and dry matter (RDMT50) were -16.5 and -16.7 °C, respectively, and most of the genotypes succeeded in retaining 50 percentage of these traits during the recovery period. MLC8 and MLC286 genotypes with RDMT50 of -16.7 °C had the highest ability to maintain dry weight, whereas MLC74 genotype with RDMT50 of -13.4 °C had the least cold tolerance in respect to dry weight during recovery. Generally, 37 genotypes had reasonable level of tolerance to freezing stress. Therefore, based on the results of this experiment these 37 genotypes can be used in lentil breeding program for target areas with a minimum temperature of -15 °C.