مجله علوم گیاهان زراعی ایران
سال پنجاه و سوم شماره 4 (زمستان 1401)

To study the effect of miRNA and PGPR on drought tolerance, Sadri and Yas bean genotypes were subjected to drought conditions (FC = 90%, 60% and 30%) and bacterial treatments (no bacteria, isolates B1, B2 and mixture 2 bacterial isolates), using CRD design with three replications in a factorial arrangement, Drought stress was applied five weeks after planting (for 10 days) and second trifoliate and root were used for sampling. The results showed that PGPRs lead to membrane stability, root development, etc. To identify the potential miRNAs involved in drought stress, the publicly available EST sequences of the plant were obtained from NCBI and blasted against the previously known Plant miRNAs. Ultimately, five distinguished potential miRNAs were acquired in the plant (belonging to four families: miR408, miR5021, miR5565e and miR9559). Candidate miRNAs were involved in growth, stress tolerance, etc. miR9559-3P expression decreased in drought and bacterial inoculation conditions in drought sensitive and tolerant plants. However, in the absence of bacterial inoculation, the expression of miR9559-3P was higher in sensitive plants. miR9559-3P might increase sensitivity to drought stress by negatively regulating role and targeting a higher percentage of target genes in sensitive plants. However, the tolerant plant with a special regulatory display and reduced expression of miR9559-3P reduced the degradation of miR9559-3P transcripts, increased the expression of the target gene and improved stress tolerance. Since PGPR modulate miRNA expression and lead to drought tolerance and increase plant yield, using these bacteria as biofertilizer can be a suitable alternative method of chemical fertilizer.

Drought stress is one of the most important environmental factors involved in the growth and yield of wheat reduction and causes many damages by disrupting morphological and physiological processes. On the other hand, putrescine as a growth stimulant with antioxidant properties in the plants can inhibit the destructive effects of dehydration stress. For this purpose, a factorial experiment based on a completely randomized design with three replications was carried out in the greenhouse of the Faculty of Agriculture, University of Mohaghegh Ardabili. Factors included water deficit stress (control, 85% and 65% of field capacity), wheat cultivars (Kuhdasht, Zagros, Gonbad and lines 23, 24, 25, 27, 28, 39 and 40) and putrescine (non-application, 0.088 and 0.176 g / L-1). Putrescine foliar application was performed in the three-leaf stage of the plant and dehydration stress was applied one day later for one week. Mean comparisons showed that dehydration stress decreased leaf chlorophyll index, F0, Fm, Fv / Fm, stem length and grain yield (grain number and grain weight) in some studied genotypes. The combination of 0.088 g / L-1 putrescine and drought stress improved the chlorophyll index (28.16%) and the amount of photosystem two (10.54%) compared to the control conditions. Also, the dendrogram obtained from cluster analysis placed the studied genotypes under dehydration stress and putrescine foliar application in three groups. In general, foliar feeding of 0.088 g / L-1 putrescine is more effective and recommended for the photosynthetic system improvement and tolerance of wheat plant to dehydration stress. Among the studied genotypes, Koohdasht, Zagros and Line 27 were more tolerant to dehydration stress due to putrescine-enhanced photosynthetic system and improved grain yield.

To evaluate the effect of crop rotation and chemical management on weed seed bank in wheat fields, a three-year experiment was conducted in split-plot design with three replications in Khuzestan province. Main plots were crop rotation (wheat-wheat-wheat, wheat-rapeseed-wheat and wheat-sugar beet-wheat) and subplots were chemical management (Untreated Control (UTC), chemical rotation and no chemical rotation (farmer program)). The results showed the change in crop rotation reduced the frequency ratio of weeds seed bank population in both evaluated depths (0 to 10 and 10 to 20 cm). Also, the combination of chemical management along with crop rotation significantly reduced weeds seed bank population. In the absence of herbicide application in the three years of experiment, the frequency ratio of winter wild oat weed seed bank population on the soil surface decreased from 2.20 to 1.48 with rapeseed and from 2.73 to 0.63 with sugar beet planting, however, in the case of non-crop rotation, the frequency of wild oat seeds in the seed bank increased. This trend was also evident in the total weed seed bank population.

In order to evaluation the genetic diversity of agronomical traits, determine the relationships between traits and the contribution of each trait in the diversity, a study was conducted on 49 mung bean accession’s in the field of the National Plant Gene Bank of Iran, in the 2019-20 growing season and the most important phenological and agronomical traits were recorded. Based on the results, grain yield, biomass, plant weight, number and weight of grains and pods per plant and number of cluster per plant had the highest coefficient of variation. The results of the factor analysis showed that plant weight, number and weight of grains and pods per plant and number of cluster per plant had the highest coefficients in the first component; Grain yield and harvest index had the highest coefficients in the second component and pod length and 100 grain weights had the highest coefficients in the third component. Cluster analysis using Ward’s method divided accessions into 3 distinct clusters.  Discriminant analysis showed that grain yield, biomass, harvest index and pods number per plant had maximum coefficient in the first function, which has the most effective role (75%) to discriminant clusters. Based on the Wilk’s Lambda values, except grains per pod, pod length and hundred grains weight, other traits had significant effect on dividing accessions into 3 clusters. High GCV, PCV, coupled with medium to high heritability of plant weight, number of grains and pods per plant, pods and grains weight per plant, cluster number per plant, 100 grain weights and harvest index, indicating that selection will be effective for these traits. Path analysis demonstrated the direct effects of biomass, harvest index and pod weight per plant on mung bean grain yield.  These results clearly elucidate that these traits had more diversity among mung bean accessions. The existence of such diversity makes possible the selection of appropriate accessions based on breeder’s desire.

Growth characteristics, phenological stages, and yield components of crops are affected by environmental conditions and can affect seed yield. The present study evaluated the duration and rate of seed filling at three layers of upper, middle, and bottom, seeds number per plant, and seed yield of five rapeseed genotypes (RGS003, Dalgan, Zabol10, Hyola401, and Hyola4815) in 6 planting dates of fall (7-Oct, 17-Oct, and 27 Oct) and winter (9-Feb, 19-Feb, and 1-Mar). Two separate experiments were performed in autumn and winter as split plots in a randomized complete block design with three replications at the research field of Seed and Plant Improvement Institute, Karaj, Iran in 2015-2016 growing seasons. In each experiment, planting dates and rapeseed genotypes were considered as the main plots and sub-plots, respectively. The results of this study showed that the values of seed yield, single seed weight, seed filling duration, and seeds per plant decreased with delay in planting, especially in winter planting dates. The number of seeds per plant was more effective in final yield formation than the single seed weight, seed filling rate, and seed filling duration. The Dalgan genotype, although having a moderate single seed weight, seed filling rate, and seed filling duration, had the highest seed yield due to its greater number of seeds per plant. Also, the rapeseed genotypes produced the highest grain yield in Oct 7 and Feb 9 planting dates in the fall and winter seasons, respectively.

Water deficit as one of the main environmental factors reduces plants yield around the world. Wheat is one of the most important cereal providing human’s food demand. Aegilops is a wild species belonging to the wheat family that can be used as a suitable germplasm to discover new genes to improve wheat tolerance to biotic and abiotic stresses in breeding programs. In this regard, 3 different species of Ae. Tauschii, Ae. Cylindrical, and Ae. Crassa , as well as wheat were cultivated under normal and water- deficit stress (FC = 25%). Morphological, physiological, biochemical, and growth indices were used to assess stress tolerance. Given the results, leaf length, width and area in plants under stress decreased sharply which the sensitive cultivar, Darya, showed the minimum value. Based on. biochemical analysis, under stress, peroxidase and catalase enzymes activities were increased either in wheat or in Aegilops, while ascorbate peroxidase decreased only in wheat in contrast to aegilops. A negative correlation was observed between catalase and ascorbate peroxidase under water-deficit stress. Among growth indices, wet and dry biomass rarely decreased in Cylindric species. According to multifactorial analysis, Ae. Cylindrical and Ae. Crassa species were more tolerant than wheat. Utilizing these could be useful to develop the tolerant cultivars to abiotic stress such as water- deficit.

Stems water soluble carbohydrates are one of the major sources of assimilates for seed filling in photosynthesis limitaton and drought stress. The objective of this study was to evaluate stem reserves accumulation capacity and its relationship with yield of wheat cultivars under cycocel (cycocel) treatments. 22 wheat cultivars were cultivated in a split plot design with three replications, cycocel foliar application and control (no cycocel) being main plots and wheat cultivars were sub plots. The amount of accumulation was estimated by measuring stem weight and stem soluble carbohydrates content (WSC). Significant variation among cultivars was observed under both cycocel and control treatments. Cycocel foliar application reduced stem length by 3.9% and increased stem specific weight by 6%. An increase in WSC content was observed in some cultivars with cycocel application. Cycocel, not only affected the distribution of photosynthetic assimilates between structural and soluble compounds in the stem, but also increased grain yield and number of seeds per spike. Cycocel increased the number of seeds per spike by 6% and grain yield by 8.2%. According to the results of cluster analysis, in both control and cyclool application treatments, Shabrang and Pishgam cultivars were the best cultivars in terms of studied traits. In conclusion, foliar application of cycocel in the second node emergence stage of wheat had a positive effect on grain yield and number of grains per spike and it aslo improved WSC accumulation capacity especially in taller cultivars.

Field experiment in Poldokhtar city (Chemeshk village) in two cropping years 2018-19 and 2019-20 in the form of split plots based on a randomized complete block design with 4 levels of the main super absorbent factor (control, 50, 75, and 100 kg/ha-1) and 6 levels of sub-factor of additive series intercropping (forage chickpea pure stand, Saral cultivar, 25×100 (chickpea×barley), 50×100, 75×100, 100×100 and pure barley (Abidar barley) was used with 125 kg of forage chickpea and 200 kg/ha-1 of barley based on pure cultivation. Each of the above values, were used based on the percentage, in order to examine their coexistence on quantitative (forage) and qualitative (protein) traits of two plants. The interaction of the three studied factors (year, superabsorbent, intercropping) showed that in proportion to the increase of absorbent factor and legume ratio, increased the total dry hay which was more in the second year than in the first. In the second year×100 kg superabsorbent×100×100 and 100×75, 18.91 and 18.79% increased chickpea forage protein, respectively. The percentage of barley protein in the composition of 100×100 in the first and second year was 6.54 and 7.1, respectively. With increasing consumption of superabsorbent and legume complementary component, decreased the amount of NDF in chickpea forage.The triple effect of year×super absorbent×intercropping had a similar pattern on fluctuations in barley forage quality (fiber percentage). Therefore, the application of agronomic management with crop diversity per unit area and moisture absorbing indicated the application of ecological principle in the exploitation of production resources.

Investigation of inheritance of agronomic traits, type of genes action and selection of appropriate breeding method is of great importance in order to achieve the maximum potential of breeding genotypes. In order to estimate the genetic components of important morphological traits were using generation mean analysis with mixed models in four basic generations (BC1, F2, F1, and BC2) resulting from crossing of maize inbred lines MO17 (drought tolerant) and B73 (drought sensitive), under water deficit stress factor at three levels of including well-watered, intermediate, and severe water deficit stress in field conditions were studied in the growing season in 2016 and 2017. The results of this research showed that the highest heterosis of F1 was observed in the well-watered for one grain weight (112%), in the intermediate stress for grain yield (59%), and in the severe stress for anthesis silking interval (59%). Average degree of dominance in well-watered for 100 grain weight trait, in intermediate stress for number of ears per plant and in severe stress for plant height and number of leaves per plant were positive and greater than one. Also, in three irrigation conditions, due to the greater dominance gene effects (dominance gene effects was obtained for grain yield in plant in well-watered condition 75, intermediate stress 115, and severe stress 63) and variance of dominance gene effects in genetic control of grain yield and important traits, the production of hybrid varieties is essential to exploit these effects.

A factorial layout based on a randomized complete block design in three repetitions was carried out to evaluate and compare the effect of early and common planting on two potato cultivars in 2018-2019 in research farms at Razi University of Kermanshah. Experimental factors included 4 planting dates (November 16, 2018- March 16, 2019- April 9, 2019- May 10, 2019) and two cultivars (Sante and Marfona). Cultivar factor affected significantly on total yield, No. of small (less than 35 mm) and medium tubers, the weight of small and medium tubers (p< 0.01), marketable yield, and tuber dry matter (p<0.05). Also there were significantly different in total yield, marketable yield, the weight of medium and large tubers, number of large tubers, the weight of infected tubers, number and length of the main stem, dry matter percentage, and tuber starch percentage between various planting dates. The highest and the lowest mean marketable tuber yield were observed in November and May planting dates, respectively (53.1 and 36.6 tonnes per hectare, respectively). Also, planting date significantly affected on infected tuber weight (p<0.01), so November planting date resulted in no infected tuber compared to other planting dates. Water consumption (m3.h-1) was 5040, 7230, and 6962 in March, April, and May planting dates, respectively, that were more than the November planting date (4350). Then, net income increased 55% from the sale of tubers by shifting the planting date from common to autumn cultivation. In addition to producing higher quality tubers, potato cultivation in the autumn had a relatively higher price in the market.

In order to investigate the role of inter-species interference and competitive outcome of barnyard grass (Echinochloa crus-galli) and bulrush (Bolboschoenus planiculmis) weeds with Guilaneh cultivar of rice, a factorial experiment with two factors including weed species (barnyard grass and bulrush) and rice: weed ratios in each pot (0: 4, 1: 3, 2: 2, 3: 1, and 4: 0) was conducted as a randomized complete-block design with three replications. The results showed that, except for height, all other traits of rice decreased more in competition with barnyard grass than competition with bulrush. The percentage of more reductions of traits in rice-barnyard grass competition than rice- bulrush competition, averaged over planting ratios, were 10 and 21% for biological yield, 12 and 23% for seed yield, 10 and 21% for number of panicle, 13 and 25% for number of filled seeds, 7 and 16 for total number of seeds, and 10 and 17% for number of tillers on pot and single plant levels, respectively. These results, along with the replacement series diagrams studies have indicated the severe competition of barnyard grass with rice plants. However, no significant difference in the competitive effect of the two weed species, as well as the insignificant dominance index and the ratio of barnyard grass and bulrush competition, indicates the importance of bulrush as a new weed in rice fields. Therefore, effective management of bulrush in addition to barnyard grass should be taken into consideration in the development of the weed management programs in paddy rice fields.

Identification of resistance gene sources in seedling and adult plant stages is important to developing durable wheat cultivars. In this study, 100 genotypes of Aegilops tauschii, collected from natural habitats were evaluated in the experimental field of the Iraqi-mahaleh, Gorgan. Seeds were planted on one meter length lines and inoculated with Golestan leaf rust pathotypes in a randomized complete block design with three replications. The reaction of genotypes was also evaluated in greenhouse, by six Iranian pathotypes based on a completely randomized design with two replications in seed and plant improvement institute (SPII). To evaluate resistance in filed, we used infection type, AUDPC, final disease severity and coefficient of infection indices. The results showed that in greenhouse, the frequency of resistant, moderately resistant, moderately susceptible and susceptible genotypes were 7, 13, 13 and 67 percent, respectively. In field, the regarding frequencies were 14, 49, 7 and 30 percent. The correlation coefficient between final severity of infection, with the values of coefficient of infection and area under the disease progress curve, were 0.97 and 0.95, respectively. Accordingly, 57 genotypes with the desired characteristics, namely final infection intensity of 3.5-40, infection coefficient of 1.4-30 and rAUDPC, 1-32% were identified with MS and MR responses for resistance. Forty-six genotypes were susceptible in seedling stage and resistant in adult plant stage. Some genotypes originated from Afghanistan, Azerbaijan, China and Uzbekistan were resistant to all isolates which could be considered as appropriate sources of resistance to leaf rust disease for breeding of cultivated wheat species.

Conservative tillage and drought resistant crops can be efficient solution to alleviate climate change impacts. We evaluated tillage effect, water deficit and nitrogen level on sorghum in a split-split plot experiment with three replications. Main plots were conventional tillage and no tillage, sub plots were 30, 60, and 90% of sorghum water requirement, and sub-sub plots were consisted of 0, 50, and 100% of recommended nitrogen. Results showed that the highest forage yield (12263 kg ha-1) was obtained with no till and 100% nitrogen. Also, the yield of sorghum in no till with moderate water stress was equal to the yield in conventional tillage with partial water stress. Under partial water stress, qualitative traits including crude fiber, acid detergent fiber and neutral detergent fiber in no till had lower values than conventional tillage. In addition, qualitative traits including digestible dry matter and water-soluble carbohydrates in no till treatment with 100% nitrogen were higher than conventional tillage. The highest percentage of crude protein in conventional tillage was obtained by using 100% nitrogen. It seems that conservation tillage can achieve acceptable yield and quality in sorghum with less water than conventional tillage, but it requires long-term and additional research.

Plant nutrition is one of the most important environmental factors affecting the yield and yield components of crops such as soybean. This study was conducted to investigate the effect of nitrogen-fixing bacteria, humic acid and foliar application of micronutrients on yield and morpho-phenological traits of soybean (cv. Saman) in a factorial randomized complete block design with three replications at Gorgan agricultural research station in two cropping seasons (2019-2020). Experimental factors include foliar application of humic acid at two levels including fulvic and humic acid; Bacterial seed at three levels including bacterial seed, bacterial seed+Azospirillium, and control; and nutrient spraying was applied at four levels including cobalt, cobalt+molybdenum, cobalt+molybdenum+boron, and control. Based on the results, the simple effects was significant on the studied traits. The bacterial Rhizobium+Azospirillum and cobalt+molybdenum+boron treatments significantly increased the traits than control. The highest grain yield was observed under the humic acid (2750 kg/ha), bacterial seed+Azospirillum (2238 kg/ha) and cobalt+molybdenum+boron (2388 kg/ha). In general, the results of this study indicate the efficiency of nitrogen-fixing bacteria as well as foliar application of micronutrients in increasing soybean yield.

In order to evaluate the phytohormones-like effects of plant-derived smoke on some biochemical characteristics of lemon balm, an experiment was conducted as a split plot in time based on complete randomized block design with three replications in research greenhouse of campus of agricultural and natural resources of Razi University in 2017. The main factor was different levels of leaf foliar application (including four concentrations of smoke-water (i.e., 1:5000, 1:1000, 1:500, and 1:100 (v/v)) accompanied with cytokinin, auxin, and gibberellic acid (each with a concentration of 50 μM), as well as the control) and the sub-factor included two harvest stages. The results indicated that the application of different concentrations of smoke-water and growth phytohormones significantly increased the content of chlorophyll and carotenoids, photosynthesis rate, transpiration rate and stomatal conductance, but reduced the accumulation of soluble carbohydrate content and the percentage of electrolyte leakage. However, chlorophyll fluorescence parameters, anthocyanin content, soluble protein content and activity rate of antioxidant enzymes were not significantly affected by foliar application levels. In general, these findings indicate that plant-derived smoke similar to growth phytohormones has a great potential to improve biochemical efficiency of lemon balm and can be considered as a natural agrochemical.

Oilseeds are one of the most important food reserves in the world and oil production from oilseeds is very important. In order to investigate the effects of sulfur fertilizer (without fertilizer (control), sulfur chemical fertilizer, sulfur-fertile biofertilizer containing thiobacillus and their combined application) on yield, yield components and seed oil of three camelina masses (Kermanshah, Sabzevar and Shahrekord), an experiment was performed as a factorial design based on randomized complete block design with three replications in the research farm of Ilam University in 2020-2021. The results of analysis of variance showed that the combined effects of sulfur + biosulfur on the number of capsules per plant and the number of seeds per capsule were significant at the level of 1% probability. Also, the weight of 1000 camelina seeds was affected by the interactions of sulfur and the type of mass. Application of sulfur fertilizers increased the amount of photosynthetic pigments in camelina leaves. The highest plant height, number of stem per plant and stem diameter were obtained by using sulfur+biosulfur fertilizers. The results also showed that the highest grain yield (2394 kg/ha) of camelina was obtained by using sulfur+biosulfur; which was 8.32% more than not consuming sulfur. The highest oil yield (5.916 kg/ha) was observed with the combined application of sulfur+biosulfur fertilizers and sulfur and biosulfur fertilizers alone were in the second place in terms of grain yield. Non-application of sulfur fertilizer (4.576 kg/ha) had the lowest grain yield, which indicates the effect of sulfur fertilizers on yield indices and camelina oil.

To evaluate the competition of millet (Panicum miliaceum L.) and soybean (Glycine max (L) Merrill) in the intercropping system, a field experiment in two years (2018-19) was conducted in a randomized complete block design with four replications at the Sari Agricultural Science and Natural Resources university. The planting ratios were 0:100, 25:75, 50:50, 75:25, and 100:0 (Soybean: Millet, respectively). The results showed that the radiation use efficiency (RUE) was higher in different intercropping ratios than the millet monoculture (0:100). In different intercropping ratios, the RUE of millet decreased significantly with increasing the share of soybean. So that in the 105 days after planting, the RUE of millet in 75:25 was 47.74 and 29.41 percent less than the expected values in studied years, respectively. Also, the planting ratio of 25:75 in the 90 days after planting had the highest chlorophyll a/b ratio in soybean and millet. The 25:75 had the most elevated land equivalent ratio index (1.23), and the millet actual yield loss (AYL) was only positive (2.01) in the 25:75. Therefore, increasing the RUE in intercropping culture and improving millet grain yield as the dominant species played an important role in increasing productivity in the planting ratio of 25:75.

Regulation of ionic homeostasis in plant cells is one of the important aspects in salt tolerance. In this study, the effect of 200 mM salinity stress after 1, 10 and 20 days of stress on some morphological characteristics, elements concentration and expression of some genes involved in salt tolerance of bread wheat genotypes, including lines 7 and 8 (salt-tolerant), line 16 (salt-sensitive) and Sistan cultivar (native tolerant cultivar) were studied factorially in a Completely Randomized Design (CRD) with three replications. The results showed that salinity stress reduced shoot biomass in all tolerant and sensitive lines with the lowest reduction in line 7. Under salt stress conditions, Na+ content had an increasing trend in all lines and K+ content had a decreasing trend. The lowest increase of Na+, and the lowest decrease of K+ and K+/Na+ ratio was observed in line 7. Under salt stress conditions, the highest expression of SOS1, SOS2 and SOS3 genes was observed in line 7 and the lowest expression was observed in lines 16 and 8. The results of this study suggest that line 7 had a higher degree of tolerance and can be considered in breeding programs as well as for additional studies in saline areas.