نشریه بیوتکنولوژی و بیوشیمی غلات
پیاپی 3 (پاییز 1401)

Knowledge of the amount of genetic diversity in germplasms provides plant breeders with valuable information for the effective preservation of genetic resources and their use. More knowledge about genetic diversity and genetic factors of diversity is very beneficial for exploring new genes. Maintaining such diversity and using it in breeding programs is one of the main principles of biological conservation and genetic breeding of crop plants.

This research was conducted to evaluate the genetic diversity in 20 different durum wheat genotypes, including landraces, improved cultivars, and breeding lines using RAPD and ISSR molecular markers. In this research, 31 RAPD primers and 13 ISSR primers were used to evaluate the genetic diversity in durum wheat genotypes.

Based on the results, the studied genotypes had significant diversity based on both molecular markers. In RAPD analysis, 31 primers amplified 319 bands, of which 204 bands were polymorphic and the percentage of polymorphic bands was estimated at 63.94%. In ISSR markers, 13 primers produced 125 bands, of which 88 bands were polymorphic and the total percentage of polymorphic bands was estimated at 70.4%. Genetic similarity and cluster analysis of RAPD and ISSR were estimated using the Jaccard coefficient. For RAPD, the similarity index values ​​ranged from 0.22 to 0.90, and for ISSR from 0.22 to 0.94, which indicated the presence of high genetic diversity at the molecular level for the studied genotypes. The results of cluster analysis and principal coordinate analysis based on each of the RAPD and ISSR markers grouped genotypes into four groups. The results of the research showed that RAPD and ISSR markers are suitable markers for genetic diversity studies in durum wheat. But the ISSR marker is preferable due to its greater compatibility with the geographical origin, high reproducibility, and the similar cost as RAPD. The results showed that the grouping patterns of durum wheat genotypes are not mainly due to their geographical origins. The results indicated that the grouping of populations in different geographical regions in similar groups is probably due to the gene flow between regions through the gradual exchange of grains between farmers. This could also be due to the previous selection for sum agronomical traits in the populations for tolerance to environmental stresses.

Based on both markers, genotype # 20 (Stj3//Bcr/lks4) showed a different response from the other genotypes, so it was placed in a separate group in the analysis based on each of the markers. Therefore, this genotype can be used as one of the parents in crossing with other genotypes in subsequent studies.

Nowadays, seed treatment with growth regulators or nutrients is widely used in the seed industry due to its significant effect on growth and yield, as well as resistance to diseases and pests. Therefore, in the present research, the effects of seed treatments with salicylic acid, humic acid, and zinc on two durum wheat cultivars were investigated under rainfed conditions.

This research was conducted as a factorial experiment based on a randomized complete blocks design (RCBD) with three replications in the research farm of the Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran, in 2019-2020. Factors included two cultivars of durum wheat (Saji and Zahab) and seed treatments (salicylic acid, humic acid, zinc, salicylic acid + humic acid, salicylic acid + zinc, humic acid + zinc, salicylic acid + humic acid + zinc, and control). Seed treatments were applied before sowing with a concentration of one millimolar (mM) salicylic acid solution, zinc solution (2%), and humic acid powder (95%) at the ratio of one kg or lit to 100, 100, and 300 kg of seeds, respectively. The investigated traits included the content of photosynthetic pigments and flag leaf area in the boot stage (code 45 on the Zadoks growth scale) and yield and yield components and seed protein percentage at the ripening stage.

The results of the analysis of variance showed that the effect of cultivars, seed treatments, and interactions between them was significant on the studied traits (except the number of spikes per square meter). The grain yield in durum wheat cv. Zahab was significantly higher than Saji. The grain yield of two cultivars in all seed treatments was higher than the control. Grain yield in Zahab was almost the same in all of the seed treatments, but in Saji, the highest grain yield was obtained in seed treatment with zinc usage (5033 kg. ha-1), and other seed treatments had the same effects. There was no significant difference between the two cultivars in terms of seed protein percentage, but the highest and lowest amount of seed protein was observed in salicylic acid + humic acid and control seed treatments with 13.14 and 12.11%, respectively. At the boot stage, the effects of cultivar and seed treatment on flag leaf area and the content of photosynthetic pigments (except carotenoids) were significant. Zahab cv. was superior to Saji in terms of flag leaf area and photosynthetic pigment content.

Based on the results of this research, durum wheat cv. Zahab had a better performance than Saji. The effect of seed treatments with salicylic acid, humic acid, zinc, and the combination of these treatments had positive and significant effects on the grain yield compared to the control.

 Heavy metals refer to a group of metals or semi-metals whose atomic density is greater than 4 or 5 grams per cubic centimeter. What has caused concern about environmental pollution today is the accumulation of the chemical waste in the soil. Although copper is a micro-element for plants, it is toxic at high concentrations. This element causes structural, morphological, physiological, and biochemical changes in plants. Today, the phytoremediation technique is used as a suitable method for cleaning and removing water, soil, and air pollution. More than 400 species of overgrown plants have been identified. Studies have shown that Aegilops tauschii is a drought-resistant plant. Since, the stress of heavy metals can cause secondary drought stress.

This research was performed to investigate the effect of the heavy metal copper on some physiological, morphological, and biochemical parameters of Aegilops tauschii. Therefore, the effect of different concentrations of copper (zero, 5, 25, and 125 micromolar) was studied on the physiological, biochemical, and morphological characteristics of 37 genotypes of Aegilops tauschii in the greenhouse condition.

 The results showed that increasing copper concentrations decreased the amount of chlorophyll b, carotenoid, cell membrane stability, seed diameter, relative leaf water content, leaf retained water and single plant yield; while total chlorophyll, chlorophyll a, carbohydrate, proline, relative leaf water loss, root length, and root weight increased significantly. In terms of biochemical parameters, Genotypes 11, 58, and 85 with the highest values of morphological, physiological, and biochemical indices were resistant to copper. Among the mentioned genotypes, Genotype 58 with the highest yield as a resistant genotype, and Genotype 23, 28, 30, 52, 99 and 123 were subjected to copper stress more than other genotypes based on the morphological, physiological and biochemical indicators, among which Genotype 99 with the lowest yield could be introduced as the most sensitive genotype.

According to the results, it seems that some genotypes of Aegilops tauschii were resistant to the heavy metal copper. Resistant genotypes could be recommended for phytoremediation in copper-contaminated areas.

 Genetic diversity in plant communities is the basis of breeding programs, and in conventional breeding programs, desirable populations are selected from within a population with high genetic diversity.

 The genetic diversity for 13 genotypes of Agropyron intermedium was studied by ISSR markers and soluble leaf proteins in the biotechnology laboratory of Kermanshah Agricultural Research and Education Center in 2019.

 Based on the results of molecular data analysis of proteins, 15 bands were observed, and polymorphism was seen in only four of them. The highest number of bands were related to genotype G12 with 15 bands and the lowest ones were related to G4 and G5 genotypes with 11 bands. In general, the leaf proteins did not have the ability to differentiate within the species. Although, based on the similarity matrix and cluster analysis for soluble leaf proteins, the genotypes were divided into three groups. The first group included genotypes G4, G5, G9, and G11. The second group consisted of genotypes G1, G2, G3, G6, G10, and G12. finally, the third group included genotypes G7, G8, and G13. The first group had the greatest genetic distance from the second group. In total, the ISSR primers were able to produce 86 bands, of which 10 bands were monomorphic and the other bands were polymorphic. The average number of bands produced by each primer for 13 genotypes was 7.17 bands. The primer of IS11, IS12, and IS14 showed the highest number of bands (10 bands), and IS3, IS9, and IS15 showed the lowest number of bands (5 bands). A desirable polymorphism between genotypes was observed based on ISSR markers and the primers of IS3, IS5, IS9, IS10, IS11, and IS14 were determined for the intraspecific diversity study of Ag. intermedium as desirable primers. According to the cluster analysis based on the data obtained from the ISSR primers, the genotypes were placed into three groups. The first group consisted of genotypes G1, G2, G3, and G5, and the average similarity coefficient for the genotypes of this group was 0.667. Genotypes G9, G11, G12, and G13 comprised the second group, and the average similarity coefficient for these three genotypes was 0.656. The third group included genotypes G4, G6, G7, G8, and G10 with an average similarity coefficient of 0.660. In addition, based on the ISSR marker, the genotypes G2 and G5 had the highest genetic distance with the genotypes G6, G7, G8, and G10.

 Genotypes G7 and G8 had the greatest distance with genotype G5. Therefore, due to their genetic distance, these two genotypes are suitable genetic materials for breeding programs and the use of heterosis in order to obtain cultivars with superior characteristics, and it is suggested to use them in future studies.

Water deficit stress is one of the most common environmental stresses which has limited agricultural production. So, research on the water deficit tolerance in crops is very important.

 In this study, 15 corn genotypes (five parents and 10 hybrids resulting from their crossing) were evaluated in two separate experiments including normal conditions (irrigation cycle of 5 days) and water deficit (irrigation cycle of 8 days) based on randomized complete blocks design with two replications in the Research Farm of Graduate University of Advanced Technology, Kerman, Iran during 2017. The chlorophylls a and b, proline, protein, and reducing sugars traits were estimated in normal and water deficit conditions.

The results of combined variance analysis showed a significant difference at the probability level of 1% for all the studied traits between genotypes (parents and hybrids) and also between two stress conditions. The interaction effect of genotype×stress was significant for all traits, which means that genotypes have shown different reactions under water deficit stress. The water deficit stress caused a significant decrease in chlorophylls a and b, carotenoids, reducing sugars and protein, and an increase in the amount of proline. The highest amount of carotenoids was related to genotype 8 (1.80 mg/gfw) under normal conditions, and the highest amount of carotenoids was related to genotype 3 (2.96 mg/gfw) under water deficit conditions. The mean comparison results showed that the amount of protein was affected by water deficit stress, that the highest amount of protein in normal conditions was related to Genotype 5 (0.00668 mg/gfw) and the water deficit conditions, the same genotype (Genotype 5) also had the highest value (0.0070 mg/gfw). The grouping of genotypes under water deficit conditions was performed by Ward's method, and the cophenetic coefficient of this method was equal to 0.77 and categorized the genotypes into three groups. Also, based on the average traits, the grouping of corn genotypes by the UPGMA method and Cophentic coefficient equal to 0.72 was able to place the genotypes in two groups.

The intolerance of corn genotypes to water deficit stress can be due to the destruction of chlorophyll, the reduction of reducing sugars and protein, as well as the insufficient increase of proline, and these biochemical changes have caused the sensitivity of corn genotypes to water deficit. Also, genotypes 4, 5, 9, and 11 could be investigated in future breeding programs due to their greater water deficit tolerance.

 Quinoa (Chenopodium quinoa Willd) a member of the Amaranthaceae family is a dicotyledon pseudocereal. Quinoa is a plant that is very resistant to unfavorable environmental conditions and shows high resistance to biotic and abiotic stresses. Quinoa seeds have a higher nutritional value than many cereal grains and contain higher quality protein and large amounts of carbohydrates, fat, vitamins, and minerals, which are used both in human food and for feeding animals. The high adaptability of this product to different weather conditions has increased the yield of its various types in countries outside of South America. The existence of nutritious compounds in quinoa seeds, including the combination of amino acids, minerals, and vitamins, has led to more research on the properties of this plant.

 The field experiment was conducted to study the relationship between agronomic traits (including plant height, panicle length, number of seeds per plant, plant yield, thousand seed weight, seed yield, biological yield, and harvest index) and mineral elements of quinoa seeds (including Zn, Fe, Mn, Na, Ca, K, and P). The experiment was conducted in the 2018-2019 growing season at the faculty of agriculture, Razi University, Kermanshah with a randomized complete blocks design as a split-plot factorial with three replications. The experimental treatments included three planting dates (March 15, April 15, and May 15) as the main factor and the combination of planting densities (40 and 60 plants/m2) with genotypes (Q29, Titicaca, and Red Carina) as subplot factor.

 The results of the experiment showed that the seed yield (2297.5 kg/ha) on the sowing date of April was significantly higher than March and May (1484.5 and 2137.7 kg/ha) sowing dates, respectively. The effect of the studied treatments on the mineral elements of quinoa seed was insignificant. The mean comparison for plant density showed that the density of 60 plants/m2 had a higher seed yield than the density of 40 plants/m2. The results of canonical correlation analysis showed that Wilk's lambda statistic was significant at a 5% probability level in the case of the first function, indicating the existence of a significant correlation between the two groups of the studied traits.

 The results of this evaluation showed that zinc (Zn) and phosphorus (P) had the highest correlation with the corresponding focal function among the mineral elements. Among the agronomical traits, the highest correlation was between the traits of 1000 seed weight and panicle length with the first focal function. Therefore, the plants with higher values of 1000 seeds weight and panicle length, can be used to select seeds with higher amounts of zinc (Zn) and phosphorus (P).

Durum wheat is the second most important crop of wheat and the tenth most important crop in the world, which includes about 6% of the area under wheat cultivation and its annual production is between 37-40 million tons. Countries with Mediterranean climates are the largest producers of durum wheat and the largest consumers of durum wheat products. Historically, durum wheat is well adapted to a dry area with variable precipitation rates and terminal heat stress, such as the Mediterranean basin. In fact, the countries of the Mediterranean basin (Algeria, Turkey, Italy, Morocco, Syria, Tunisia, France, Spain, and Greece) account for almost 50% of the world's cultivated area and production of durum wheat. Outside this basin, Canada, Mexico, the United States, Russia, Kazakhstan, Azerbaijan, and India are the largest producers of durum wheat, respectively. Durum wheat is genetically, morphologically, and physiologically different from bread wheat, and in terms of chemical compounds, its amount of protein, minerals, vitamins, and carotenoid pigments is higher than bread wheat. Durum wheat with hard vitreous and yellow grains, in addition to providing an important source of energy, possessing a wide range of minerals and vitamins, protein and gluten, beta-carotene pigment (antioxidants and anti-cancer compounds) as well as simple carbohydrates, minerals, and other nutrients compounds that are essential in the human diet. Durum wheat is one of the most important foods with a high percentage of protein (12-14% and sometimes up to 22%) compared to rice (7%) and bread wheat (10 to 12%). In durum wheat, the amount of calcium, iron, magnesium, phosphorus, potassium, zinc, and copper is much higher than the amount of these elements in bread wheat and brown and white rice. The high content of these elements in durum wheat grain indicates the importance of the nutritional value of this product compared to the mentioned products that provide a major part of the consumer's food basket. In addition to semolina, which is used in the preparation of paste products such as macaroni and spaghetti, lasagna, noodle, etc., durum wheat is used in the making of other products such as bulgur, couscous, freekeh, durum wheat bread, etc. In this review article, the aim is to study the geographical distribution and production of durum wheat in different regions of the world, to introduce the nutritional value of the products and their products and their preparation, as well as to study the economic value of this valuable product. Moreover, new-released durum wheat cultivars with appropriate agronomic characteristics will be introduced.