Journal of Plant Physiology and Breeding
Volume:12 Issue: 2, Summer-Autumn 2022

A field experiment was conducted as a split-plot based on a randomized complete block design with three replications in 2020 to investigate the effect of different salicylic acid (SA) levels on physiological traits and grain, oil, and protein yields of maize (MV 524). The irrigation treatments were normal irrigation (irrigation after 60 mm evaporation), and irrigation disruptions from tassel emergence up to seed formation and from tassel emergence up to harvest maturity. The plants were sprayed with three levels of SA (1, 2, and 3 mM) and water at the tassel emergence stage. The irrigation and SA treatments were assigned to the main and subplots, respectively. Irrigation disruption at reproductive stages caused a decline in mean leaf water content (LWC), membrane stability index (MSI), chlorophyll content, leaf area index (LAI), grain yield, oil percentage, oil and protein yields, and an increment in leaf temperature and protein percentage, compared to normal irrigation. Application of SA, especially with 3 mM concentration, increased mean LWC, MSI, chlorophyll content, LAI, and grain, oil, and protein yields of maize. The highest positive correlation with grain, oil, and protein yields was recorded for LAI, followed by LWC and chlorophyll content index. These results suggest that water supply at reproductive stages is essential for successful maize production. Nevertheless, a foliar spray of 3 mM SA can improve the field performance and productivity of maize under normal and limited water availability.

Environmental factors such as temperature have negative effects on the reproductive phase and can cause yield loss in Citrus species. Pollen grains play a key and essential role in the fertility of plants. Quercetin and gamma-aminobutyric acid (GABA) are involved in certain biochemical functions to regulate growth and increase tolerance to biotic and abiotic stresses. The purpose of this study was to evaluate the effect of different temperatures on pollen germination and also on the levels of quercetin and GABA. The branches containing flowers of Cirus reticulata, C. sinensis, and C. paradisi were exposed to 5, 10, 15, 20, and 25 °C for six hours and then pollen grains were collected. Levels of quercetin and GABA were quantified by HPLC. The amount of quercetin was highest at 5 °C and then decreased by increasing the temperature in all species. Also, with increasing temperature, the amount of GABA decreased in all species. The highest and lowest pollen germination was observed at 25 °C and 5 °C, respectively.

Textile dye wastes are significant sources of pollution on a global scale. Numerous plants may survive and degrade various forms of poisons in contaminated settings. To survey broad bean (Vicia faba L.) tolerance to three types of dye (Acid Yellow, Acid Red, Direct Blue) at five concentrations (0, 30, 50, 70, and 90 mg/L) during three growing stages (seedling, pre-flowering, flowering), a greenhouse experiment was conducted at the University of Tabriz in 2020. The dye type did not affect the number of pods, fresh roots weight, leaf area, root length, proline content, and superoxide dismutase (SOD) enzyme activity. The control treatment had the highest pods (3.22 numbers per plant), the maximum leaf area (13380 mm2), and the heaviest root fresh weight (9.40 g per plant). The number of pods per plant decreased by 42.05, 40.01, and 19.30 percent in the Direct Blue, Acid Red, and Acid Yellow, respectively, compared to the control. Increasing the dye concentration decreased the pod number, leaf area, and root fresh weight. SOD activity and proline content increased at the dye concentration of 90 mg/L. Tolerance to maximum dye concentration by broad bean plants and increasing SOD activity and proline content showed that this plant could survive this stressful condition. These findings allow us to propose broad bean as an efficient phytoremediation species.

Intercropping improves the efficiency of using resources such as water, nutrients, and solar radiation, which consequently increases yield per unit area. Moreover, it enhances soil fertility and plant nutrient supply. This study was conducted to evaluate the grain yield and production of dragon head essential oil under intercropping with chickpeas. The experiment was arranged in a randomized complete block design with three replications. Intercropping patterns included the pure stand of dragon's head, monoculture of two chickpea varieties (Azad, Arman), additive intercropping of the optimal density of Azad and Arman chickpea + 40%, 60%, and 80% of the optimum density of dragon's head. The highest and lowest biomass and grain yield of the dragon's head were obtained in sole cropping and 80% dragon's head + 100% Azad chickpea, respectively. Moreover, the highest essential oil content and yield of the dragon's head were obtained from the cropping pattern of 60% dragon's head + 100% Azad chickpea. Also, the land equivalent ratio (LER) was greater than one for all intercropping patterns, except for the intercropping of 80% dragon's head along with 100% Arman and Azad chickpeas, and the highest partial LER of dragon's head was obtained from intercropping of 40% dragon's head with100% Arman chickpea. In general, intercropping 40% dragon's head with100% density of both cultivars of the chickpea seems a suitable model for intercropping these two crops.

This study aimed to investigate the effect of chalcone-based nanocomposite in various concentrations on lettuce plants under salinity treatment. The composite was synthesized by chemical methods with a mean particle size of 89.4 ± 4.2 nm. The factors consisted of salinity concentrations of 100, 125, and 150 mmol/l and nanocomposite concentrations of 0.1 and 0.01 ppm. After harvest, different physiological and biochemical characteristics were measured. The results indicated that the nanocomposite significantly increased the fresh and dry weight of roots and glycine betaine in the lettuce plants at higher salinity stress conditions (150 mmol/l). Contrarily, the nanocomposite significantly reduced malondialdehyde at the salinity stress conditions. Also, the nanocomposite caused a significant increase in total flavonoid content under the salinity stress conditions of 150 mmol/l and activity of ascorbate peroxidase, an antioxidant enzyme, at the salt concentration of 150 mmol/l. It can be concluded that chalcone-based nanocomposite may ameliorate the negative effects of the salinity stress on plants.

Drought stress is a critical abiotic stress that has a negative effect on plant productivity. Plant growth-promoting rhizobacteria (PGPR) such as Azotobacter and Azospirillium positively affect plant physiology, especially under drought stress. The recent study aimed to examine the effects of Mycorrhiza fungi and PGPR on the activity of antioxidant enzymes and the amount of nutrient absorption under water deficit conditions. A factorial experiment was performed based on a randomized complete block design with three replications. Factors were irrigation (regular irrigation, water deficit at the grain filling stage, water deficit at the flowering stage, no irrigation) and Mycorrhiza fungi and PGPR (Azotobacte rcoroccum, Azospirillum lipoferum, Mycorrhiza arbuscularas, Azotobacter coroccum + Azospirillum lipoferum, Azotobacte rcoroccum + Mycorrhiza arbuscular, Azospirillum lipoferum + Maycorrhiza arbuscular, Azotobacte rcoroccum + Azospirillum lipoferum + Mycorrhiza arbuscular, no inoculation). Drought stress decreased chlorophyll content and absorption of elements and increased proline, catalase, and peroxidase activity. Also, biofertilizers reduced the amount of proline, catalase, and peroxidase. They increased the amount of chlorophyll content and absorption of elements.

Iris pseudacorus is a highly valuable ornamental and medicinal plant. Chitin is one of the most abundant polysaccharides in nature and is widely used in agriculture for seed germination to stimulate plant growth. Chitosan can be used as an antibacterial component and can increase plant resistance to diseases. This study was conducted based on a completely randomized design. Treatments consisted of different concentrations of chitosan (0, 5, 10, 20, 40, 80, and 120 ppm) with five replications. Morphological and physiological traits including leaf number, leaf weight, plantlets height, leaf area, percentage of regeneration, chlorophyll a, b and total, total phenol, and flavonoids were evaluated. Results of the analysis of variance showed that chitosan significantly affected leaf number, regeneration percentage, phenol content, and leaf fresh weight. Flavonoids, chlorophyll a and b, total chlorophyll were also significantly affected. Results also showed that the highest (31.60 mg/g gallic acid) and lowest (15.51 mg/g gallic acid) total phenol content was obtained from 120 ppm chitosan and control samples, respectively. The highest flavonoid content (5.78 mM/g) was obtained by 120 ppm chitosan and the lowest value (3.20 mM/g) was recorded in the control treatment. In general, our investigation showed that chitosan had a positive effect on all measured traits. In most of the measured traits, the best chitosan concentration was 120 ppm.

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume, widely distributed in the northern temperate region and has received renewed interest in the world. This experiment was carried out to proceed from the previously-produced Syn1 generation of a new synthetic variety to the Syn2 generation. The Syn2 generation was produced and evaluated during the 2015-2019 growing seasons. In the first two years, the seeds of the Syn2 generation and composite varieties were produced in completely isolated condition. Then, the Syn2 generation along with the Composite, Sarab, and Bostan-Abad varieties were evaluated in the field conditions for three years (2017-2019). Significant differences were observed for the fresh and dry matter yield and plant height among the studied sainfoin varieties. The Synthetic variety showed the highest annual fresh forage yield (36785 kg ha-1) which was significantly different from other varieties. A similar result was obtained for the annual total dry matter yield, and the Synthetic variety showed the highest dry matter yield (11715 kg ha-1). The superiority of the Synthetic variety over the average of the ecotypes of Sarab and Bostan-Abad was about 25% for the dry matter and fresh forage yield. The plant height of the Synthetic variety was 83 cm, which was higher than other varieties. Among the studied varieties, no significant differences were observed for the traits related to forage quality. The protein content, total ash, crude fiber, water-soluble carbohydrates, and acid detergent fiber in the Synthetic variety were 18.52, 7.40, 19.95, 44.70, and 19.6%, respectively. The results indicated

Jujube (Ziziphus jujuba Mill.), with high nutritional value, is an important medicinal plant and is consumed worldwide as fresh and dry fruit. Iran is one of the most important germplasm centers for jujube. Jujube fruits are rich in mineral nutrients, protein, carbohydrates, and vitamin C. In this study, 12 different wild accessions of jujube were collected from different regions of Isfahan province. A total of thirty-four morphological and biochemical traits were evaluated. Significant differences were detected among accessions. The highest values of fruit length, fruit width, fruit weight, moisture percent, fruit flesh weight, flesh/stone ratio, stone weight, stone length, and stone width were 32.36 mm, 21.68 mm, 7.00 g, 87.11%, 6.61 g, 19.15, 0.39 g, 18.46 mm, and 7.45 mm, respectively. The highest level of total acidity content was observed in the Mahabad accession (1.38%) and the highest level of total soluble solids content was observed in the Poodeh accession (39.6% °Brix). The highest level of ascorbic acid and flavonoid content was measured in the Zavvareh (403.62 mg/kg DW) and Ganje-Ghobad accessions (250.12 mg/kg DW), respectively. The range of total phenolic compounds and mucilage content was from 8.8 to 37.97 (mg/kg DW) and 18.85 to 37.97 (mg/kg DW), respectively. The Anarak accession had the highest Zn (0.82 mg/100 g), Mn (58.37 mg/100 g), and K (698.72 mg/100 g) content, while the highest Fe (11.28 mg/100 g) and Ca (120.09 mg/100 g) content was observed in the Poodeh accession. In addition, the richest source of P (119.94 mg/100 g) was identified in the Kachoomesghal accession. Ganje-Ghobad, Poodeh, Koohpayeh, Anarak, and Zavvareh accessions showed higher values for morphological, and biochemical traits, which can be used for selecting specific genotypes for special purposes in the breeding programs of jujube and for drug industries.

Wild oregano (Origanum vulgare L.) belonging to the Labiate family is one of the most important medicinal plants in Iran and the world. It is widely used in the medicinal, food, and health industries. The present study aimed to investigate the in vitro culture of Iranian native oregano. Two experiments were designed to investigate the proliferation and rooting of this species. In the proliferation stage, benzyl adenine (BA) was used at four levels (0, 0.5, 1, and 1.5 mg/l) along with 0.25 mg/l indole butyric acid (IBA). For the rooting stage, IBA at four levels (0, 0.5, 1, and 1.5 mg/l) in combination with 0.5 mg/l naphthalene acetic acid (NAA) was used. The results showed that BA caused a significant effect on the leaf number, the number of shoots, the shoot length, chlorophyll index, and the leaf dry weight. The highest number of leaves and shoots and the highest value of chlorophyll index were seen in the medium containing 1.5 mg/l. The longest shoot and the highest leaf dry weight were related to 1 mg/l BA. In addition, the results related to the rooting stage showed that the root length, root diameter, and total dry weight of plantlets were significantly affected by IBA, while the number of roots was not influenced by IBA. The highest root diameter and total dry weight of plantlets were obtained in the medium containing 0.5 mg/l IBA, and the maximum root length was obtained in the MS medium without IBA.

The present study used the association mapping method to identify molecular markers associated with morphological traits using 407 SSR and AFLP markers for 148 barley genotypes. This experiment was carried out as an alpha-lattice design with five incomplete blocks in two replications under normal and salinity stress conditions (EC = 12 ds m-1) at the Agriculture and Natural Resources Research Station, Yazd, Iran. The genetic structure of the population was divided into two subpopulations (K = 2) using the Bayesian method and Structure 2.3.4 software. Association mapping was performed based on a mixed linear model using TASSEL4.3.15 software. Association mapping under normal and salinity stress conditions identified 38 and 43 significant marker-trait associations. Also, several common QTLs for the studied traits were identified. Common markers among traits can be due to pleiotropic effects or linkage between genomic regions involved in these traits. Several QTLs were stable for plant height and flag leaf area in different environmental conditions and can be regarded as stable QTLs. Markers HVM40-144, HVM40-147, HVM40-152, and HVM40-162 for plant height and marker Bmag0606-147 for flag leaf area showed a significant association with these traits in both normal and salinity-stress experiments. So, these QTLs can be suggested as stable gene loci. Identifying major gene loci influencing salinity tolerance in barley can assist in the breeding of salinity tolerance in this crop.

Introducing new sweet cherry cultivars with early ripening time is one of the most important goals of cherry breeding programs in Iran. The Attar cultivar was selected from the native sweet cherry germplasms of the Khorasan Razavi province by implementing eight research projects for 21 years since 1998. Evaluation of the vegetative, reproductive, and pomological characteristics of the genotypes along with other cultivars during 2005-2020 led to the introduction of the Attar cultivar. The results showed that Attar had semi-spreading tree habits with a moderate degree of branching. The time of the first flowering for Attar was in the second week of April. Results showed that this cultivar was self-incompatible. Siyah-e-Mashhad, Sweet Heart, and Dovomras-e-Mashhad cultivars were suitable pollinizers for the Attar cultivar. The harvesting time of Attar was in the first week of June. The average fruit weight of the Attar cultivar (7.73 g) was higher than those of the Shandiz (7.23 g) and Toos (6.87 g) cultivars. Also, the total soluble solids in Attar (19.87%) were higher than the Shandiz (16.63%) and Toos (17.13%) cultivars. The fruit yield of Attar in the economic fruiting stage was 40 kg per tree, which was higher than the Shandiz cultivar (22.43 kg). Fruit cracking disorder in the Attar cultivar was lower than other cultivars. Attar has a high economic value and therefore the development of this cherry cultivar can play an important role in increasing the income of cherry producers.