JOURNAL OF PLANT ENVIRONMENTAL PHYSIOLOGY
Year:2019 | Volume:13 | Issue:4 (52) |Papers Count:8

The purpose of this study was evaluation of the effects of Azotobacter nitrogen fixation bacteria in combination with Pseudomonas putida phosphate solubilizing bacteria on reducing the effects of irrigation water shortage on soybean cultivars under field conditions. This study was carried out as a factorial experiment in a randomized complete block design with three replications in Tarbiat Modarres University during 2015-2016. Treatments were irrigation including optimal irrigation, mild stress, moderate stress, and severe stress based on 15, 30, 45, and 60 percent of available water depletion, respectively from the establishment time to the end of the growth period and four levels of soybean inoculation with bacteria (control or without bacteria, inoculum with Azotobacter, inoculation with Pseudomonas putida, and inoculation with both bacteria). Results showed that the main effect of irrigation regime on all traits were significant except 1000 seed weight and the main effects of bio-fertilizer were significant except for 1000 seed weight, seed nitrogen, and oil on all traits. From the test results, one can conclude that Azotobacter alone increased 17. 9% seed yield, Pseudomonas putida alone increased the yield of 32. 4%, and the combined application of both bacteria increased the grain yield by 39. 8%. In general, considering the non-insignificant effect of bio-fertilizer interaction on levels of water stress, it was concluded that the application of bio-fertilizer under favorable irrigation conditions and under drought conditions is effective in improving yield and yield components, protein, and oil yield of soybeans.

Fig (Ficuscariaca) is native to western and eastern Mediterranean regions including Iran. Iran is one of the important producers of fig in the world. In this study, biochemical and phytochemical properties and genetic diversity of 38 fig genotypes from Arsbaran in East Azerbaijan province were investigated in the Horticulture Laboratory of Urmia University in 2015. Results of ANOVA analysis showed that, TSS, pH, TSS/TA, vitamin C, antioxidant capacity, anthocyanin, total flavonoid, and total phenol were significant (p ≤ 0. 01). Most of the studied biochemical traits indicated high variation. The results of the molecular data analysis showed that a total of 131 bands were scored, of which 121 bands (92%) were polymorphic. The amount of polymorphic (PIC) information for the primers used varied from 0. 22 to 0. 47 in ISSR7 and ISSR20, respectively. Also, marker index was between 0. 15 and 2. 5 in ISSR7 and ISSR20, respectively. Based on the results of cluster analysis, the studied fig genotypes were classified into two main groups and most of the genotypes collected from Kalibar belonged to the second group. This suggests that geographic location of the studied fig genotypes is the main reason for their separation by this marker. Based on the obtained results, genotypes Kh9 and H17 were suggested for breeding programs.

To investigate the effects of plant growth regulators on reducing skin burst disease in Thomson-Novel orange fruit (Citrus sinensis L. Osbeck cv Thomson Novel) a research project was carried out in the form of randomized complete block design using 2, 4-dichlorophenoxy acetic acid (2, 4-D) at concentrations of 0, 10, and 20 mg. l-1 and gibberellic acid (GA3) with at concentrations of 0, 50, and 100 mg. l-1 during full bloom, petals drop, and immediately after physiologic fruit drop in two consecutive years 2015-2016. The percentage of splitting, the fruit yield, skin thickness, total soluble solids, and activities of cellulase and superoxide dismutase enzymes were measured. According to the obtained results from a comparison of the means, the maximum thickness of the fruit skin, total soluble solids, performance, and superoxide dismutase were obtained under 20 mg. l-1 2, 4-D with 100 mg. l-1gibbrrlic acid treatment while minimum cellulase activity and the percentage of the fruit splitting was obtained under the same treatment.

In order to classify and compare 27 cultivars of mangoes in Kerman and Hormozgan, southern Iran, physiological traits of leaves and fruit of mango were measured on the basis of the universal descriptor. The results of analysis of variance showed that the effects of genotype were significant on chlorophyll b, total chlorophyll, carotenoids, electrolyte leakage, anthocyanin’ s, leaf, fruit pH, soluble solids, vitamin C (ascorbic acid), fruit juices TSS, and the kernel traits (kernel length, kernel thickness, kernel width, kernel weight, and kernel dry weight) at 1% probability level. The results of the comparison of the means showed that the highest levels of ascorbic acid, total soluble solids, and total leaf chlorophyll belonged to the Sindyderi, Twin, and Kharvest genotypes, respectively. Mean kernel length was observed in Nabati 1 genotype (3. 9 cm) while Anonym 1 had the maximum mean kernel length (11. 66 cm). Moreover, Nabati 1 genotype and Langra had the minimum and the maximum (2. 8 and 4. 7 cm) in mean kernel width, respectively among the genotypes studied. Also, the maximum tree yields were obtained from Snyderi genotype (260 kg), although it was not significantly difference from Shahani 2 genotype (240 kg). Cluster analysis based on the mean distance between groups (UPGMA) places these genotypes in four groups with a 7. 09 interval.

In ordr to investigate the effects of foliar spraying of seaweed extract on the growth, yield, and biochemical characteristics of bitter squash plant (Carla), a randomized complete block design was adopted with three replications under field conditions the Research station of Faculty of Agriculture University of Birjand during growing season of 2016. Treatments included four levels of seaweed extract (0, 1. 5, 3, and 4. 5 ml. L) during three stages of foliar spraying (before flowering, flowering, and fruit set time). Findings showed that leaf growth indices were influenced by seaweed extract treatments, so that with increasing treatment levels, fresh and dry weight and leaf area also increased. The seaweed extract affected photosynthetic pigments (chl a, chl b, total chl, and carotenoid). The highest levels of chl a, b, total chl, and carotenoid were obtained in plants treated with 4. 5 ml. L seaweed extract while the lowest values were recorded in the control. Results also showed that seaweed extract improved quantitative characteristics of bush, so that the highest bush length and number of lateral branches were obtained at the highest level of the seaweed extract while the lowest values were recorded in the control. Application of different levels of seaweed extract had a positive effect on the yield indices (weight, length, and diameter of the fruit, number of fruits, and yield) and biochemical characteristics of fruit (antioxidants activity and total phenol). The highest yield, total phenol and antioxidant activity were obtained in plants treated with 4. 5 ml. L seaweed extract. Generally, the findings of the current study revealed that the use of 4. 5 ml. L seaweed extract had strong impact on qualitative characteristics of bitter squash in the study.

Nitrogen is the most important element in plant growth and yield. There are several sources for supplying plants with nitrogen, including the use of chemical fertilizers. But excessive use of chemical fertilizers in addition to contamination of water and soil has also caused a threat to the health of the community. Therefore, optimizing the use of chemical fertilizers and replacing them with organic sources can be a step forward in improving the health of the community. For this purpose, a field experiment with different levels of urea fertilizer and various nitrogen sources was carried out in a factorial arrangement and a randomized complete block design with three replications on strawberry in 2016 at Someh-Sara, Gilan, Iran. The experimental factors included urea (0, 75 and 150 kg. ha-1) and various sources of nitrogen (Azospirilum, Azotobacter, Nano-nitrogen, and Control). Results showed that the application of urea fertilizer increased the shoot weight and shoot length, but decreased total antioxidant capacity, total flavonoid compounds, and vitamin C. The highest fresh weight of shoot and fruit number were obtained from nano-nitrogen treatment + 75kg. ha-1 while the highest amounts of vitamin C, total antioxidant capacity, and total flavonoid compounds were obtained from Azotobacter and Azospirilum inoculated plants. Azotobacter was superior to Azospirilum in most of the traits and with increasing the application of urea fertilizer, it maintained its efficiency compared to the control. The highest fruit yield was obtained from nano-nitrogen + 75kg. ha-1, but there was no statistically significant difference from Azotobacter + 75kg. ha-1. Therefore, since the aim of the experiment was to increase the yield and quality of the fruit, Azotobacter + 75kg. ha-1 is recommended as compared with the other treatments.

Beech (Fagus orientalis Lipsky) is one of the exceptional and extremely valuable species in the forests of northern Iran and examining the quantitative indicators in both pure and mixed stand can determine the recovery or destruction of a forest population. Accordingly, a pure and a mixed stand of parcel 319 with an area of 54 acres were considered for the study with similar conditions after a jungle cruise and field study in Asalem-Nav forests. Then, 30 poles of old beech trees with a diameter of more than one meter were selected randomly and some of quantitative and qualitative characteristics were measured. Results showed there was no significant difference between beeches of the two stands in the diameter at breast height, total height, trunk length, and percentage of trunk length slenderness. On the other hand, qualitative variables of crown symmetry in both symmetric and asymmetric trees, trunk twisting in three modes (lack of twisting, sensible twisting to the right, and subtle twisting to the left), mode of branching on beech tree trunk with divisions of branchless, low-branching, and high branching showed significant differences (P≤ 0. 5). Furthermore, allelopathic performance of a variety of tree species adjacent to the beach with mixed stand led to a significant reduction in the content of photosynthetic pigments chl. a, chl. a+b, and carotenoids while flavonoid concentration in the mixed stand indicated a considerable increase compared to the pure stand population. Results also indicated that the percentage of symmetry in the crowns of the trees in pure stand was more but the higher mean tree length and asymmetric crown in the mixed stand can be due to the existence of other species and competition for more light.

Salicylic acid (SA) is an antioxidant which has been used in recent years to increase the resistance of plants against stresses. In this study, the effect of different concentrations of salicylic acid (0. 1, 0. 7, 1. 5, 3, 6 and 9 mM) on germination, shoot and root length, anthocyanin, reduced sugars, protein, ascorbic acid, dehydroascorbic acid, and proline were investigated in pepper 5 weeks after germination. Results showed that 0. 1, 0. 7, 1. 5 and 3 mM SA increased germination and shoot and root length while 6 and 9 mM SA concentrations decreased germination percent and shoot and root length. Also, concentrations of 1. 5 and 3 mM SA decreased ascorbic acid and dehydroascorbic acid content while concentrations 6 and 9 mM of SA increased ascorbic acid and dehydroascorbic acid content in the leaf of pepper plant. In addition, concentrations of 1. 5 and 3 mM SA caused significant increase in sugars and protein content in the treated leaf but 6 and 9 mM of concentrations SA decreased sugars and protein content. Furthermore, research findings showed that under experimental conditions, different concentrations of SA (0. 7, 1. 5, 3, 6 and 9 mM) increased anthocyanin and proline contents in the leaf of pepper. In general, treatment of pepper with low concentration of SA had positive effects on plant growth while higher concentrations negatively affected the growth in pepper plant.