جستجوی مقالات مرتبط با کلیدواژه « potato » در نشریات گروه « زراعت »

The interaction of genotype with the environment provides the possibility of selecting stable genotypes for a wide range of environments. Evaluation of the interaction of genotype with the environment is necessary to increase the efficiency of selecting varieties with high and stable performance in a wide range of different environments. The objectives of this paper are: (1) evaluating the stability of 60 potato genotypes for tuber yield in two years using parametric and non-parametric stability methods, (2) identifying genotypes with good and stable performance when evaluated in variable environments and (3) investigating the relationship and correlation between stability statistics of tuber performance under water deficit conditions in Iran.

To evaluate the performance stability and adaptability of the 60 potato genotypes, two cultivars and 58 advanced clones, 17 parametric and non-parametric statistics were evaluated for tuber yield across eight environments during the 2018-2019 growing seasons. The genotypes were evaluated under normal and water deficit conditions in Karaj and Ardabil. In this study, the parametric analysis for yield was determined by such parameters as regression coefficient (bi), environmental variance (Si2), coefficient of variation (CVi), deviation from regression (sdi2), and Wricke’s ecovalence (Wi2), The non-parametric analysis included Nassar and Huhn's statistics (S(1) and S(2)), Huhn's equation (S(3) and S(6)), Shukla’s stability variance (σ2i), Plaisted and Peterson’s (θi), Thennarasu’s non-parametric (NP(1), NP(2), NP(3), and NP(4)), and Kang’s rank-sum (KR) parameter. Parametric and non-parametric statistics are used by agronomists and plant breeders. Currently, researchers are interested in applying several stability statistics to obtain the desired results, crucial for the selection of stable varieties

Composite variance analysis showed that the effect of place and year as well as the effect of genotype are significant. The interaction effect of year × location × genotype was significant at the probability level of 1%. The genotype effect was also significant at the 1% probability level. The interaction effect of genotype x location and genotype x year was not significant, which indicates that the average performance of genotypes is not different in different locations and years. Grouping of genotypes based on average performance and parametric and non-parametric stability statistics showed that genotypes are divided into four main groups. In general, based on the average rank of parametric and non-parametric stability parameters, genotypes G31, G21 and G36 had the least changes and were recognized as the most stable genotypes, and therefore they can be introduced as stable genotypes. The results of stability statistics and cluster analysis showed that G31, G21 and G36 genotypes can be introduced as stable and compatible genotypes.

Our results showed that G21, G31 and G36 genotypes contributed the least to the genetic × environment interaction (G*E) and were considered as stable genotypes under water deficit conditions. The different parametric and non-parametric stability procedures can be proposed to select drought tolerant genotypes under different environments conditions; these procedures could be useable for recognition of the best genotypes under drought stress conditions. Therefore, the analysis of yield stability could be utilized in combination with parametric and non-parametric methods to evaluate and identify drought tolerance genotypes. Dendrogram results confirmed each other with the results of parametric and non-parametric statistics. While G49, G51, G53 and G56 genotypes with the highest values were the most unstable genotypes.

Due to the trend of population growth, the need to produce more potatoes by improving agricultural management is inevitable. One of the important challenges in agriculture is the management of weeds that, if not controlled, can lead to the destruction of agricultural products and decrease the productivity of agricultural lands. The use of chemical pesticides in agriculture in addition to being able to harm human and animal health, but also lead to environmental pollution and weed resistance to pesticides. For this reason, searching for non-chemical methods of weed management is of particular importance. Today, many believe that the key to successful weed control, especially in sustainable agricultural systems, is the use of cultivars with high competitive ability. This experiment was carried out in 1400-1401 and 1401-1402 on potato plant as a split plot in 3 replications. The first factor was the cultivation of three different potato varieties (Agria, Jely and Lady Rosetta) and the second factor included 5 types of management (complete weeding, rye cover crop, clover cover crop, paraquat herbicide and control). In total, rye, paraquat and clover treatments reduced the dry weight of weeds by 53.63%, 2.40% and 48.36%, respectively. Potato tuber yield increased by 63.75%, 53.21%, 47% and 1.72% in weeding, rye, clover and paraquat treatments compared to the control. According to the results, it was said that cover plants appeared effectively in reducing the density of weeds. The speed of height increase and the percentage of cover were also different in all three cultivars. In the trait of height Agria > Jeli > Lady Rosetta and in the percentage of cover Lady Rosetta > Agria > Jeli appeared.

Potato (solanum tubrusum) is the fourth staple food after rice, wheat and corn. It is the most important tuberous crop. Potato color flesh is one of the most important parameters in food industry and marketability. The flesh color of the tetraploid cultivars range from white to cream and yellow to dark yellow. There are a few cultivars with red or blue/pink flesh color. Based on mutant clones containing superior quantitative and qualitative traits and flesh color change in Caesar potato variety, this research was carried out with the aim of determination of the reason of color flesh change in Caesar mutant.

Mutant and parent (Caesar) clone were cultivated in research farm of Ardabil Agriculture Research Center in 1397. Sampling was done in 4 replications for each clone. Changes in total carotenoid and its components were performed by spectroscopy-UV and HPLC-chromatography, respectively.

Carotenoid content in mutant clone was 319.54(µg/100 FW) and in parent clone was 246.36 (µg/100 FW). This result showed that content of total carotenoid in mutant was 1.3 times the carotenoid content of the parent. HPLC results showed that Lutein content was increased in mutant in comparison to parent, whereas, violaxantin was higher in parent that mutant clone.

Based on our results total carotenoid content along with lutein play an important role in potato color flesh change. Our finding is in accordance with results of other researches that showed that flesh color change from cream (parent) to yellow (mutant) was affected by total carotenoid content generally and lutein specifically.

Potato (Solanum tubersum) is an important economic crop in the world. In order to investigate the effect of potassium (Potabarvar Bioferrtilizer) and Phosphorus (Barvar 2 Biofertilizer) biofertilizers on the yield and quality of two families of true potato seeds, including Fanta free pollinators and Savalan × Agria hybrids, an experiment was conducted in the form of a completely randomized block design with 8 treatments and three repetitions were done. The results showed that the use of Potabarvar Bioferrtilizer and Barvar 2 Biofertilizer affected plant height, leaf area and the dry matter percentage of tuber and leaf and led to an increase in yield compared to the control plants and the application of a mixture of biological fertilizers at the probability level of 1%. So that the highest yield in the treatment of Potabarvar biofertilizer was obtained on the free-pollinating Fanta family. Also, the application of these fertilizers led to an increase in the leaf chlorophyll index at the five percent probability level. The use of these biofertilizers led to an increase in the concentration of potassium, nitrogen and phosphorus elements in the plant at the level of 1% probability. The application of these fertilizers had a greater effect on the free-pollinating Fanta family. Also, the application of the mixture of these biofertilizers did not lead to an increase in the desired indicators.

To evaluate effect of genotype and plantlet age on the yield and yield components of potato minitubers, this study was conducted under aeroponic system conditions in Ardabil agricultural and natural resources research station and Behparvar Sabalan Ardabil Company in Aradbil in Iran. Four potato genotypes including; promising clones C-397097-2, C-397081-1, cv. Agria and cv. Caesar, and three plantlet ages including; 30, 40 and 50 days were experimented as factorial arrangements in completely randomized design with three replications. The results showed that tuberization and development of minitubers was delayed in the aeroponic system. The effect of plantlet age on yield and yield components was more pronounced than genotype. The effect of plantlet age was significant (P≤0.05) on all traits. Genotype × plantlet age interaction was significant for yield and yield components, except for single minituber weight. Clone C-397081-1 of 30-day plantlet age produced the highest minitubers plant-1 (57.3 minitubers plant-1). For cv. Caesar and clone C-397097-2 of 40 days plantlet age were the best and produced on average 55.57 and 53.54 minitubers plant-1, respectively. There was no significant difference between plantlet ages of 30 and 40 days for clone C-397097-2. The cv. Agria had the best response at the plantlet age of 40 days and had on average 45.7 minitubers plant-1. Clone C- 397081-1, C-397097-2, cv. Agria and cv. Caesar produced on average 1203, 1235, 1113 and 1223 m-2, respectively. Forward stepwise regression analysis showed that the mean single minituber weight and minituber weight plant-1 was important in the selection of potato genotype for production of large number of minitubers. The mean weight of single minituber and plant height were inversely related to minituber number. In conclusion, the maximum economic minituber production for each potato genotype was affected by the plantlets age. The plantlet age between 30 and 40 days was identified as suitable for transferring potato plantlets to areoponic system.

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.

Water deficit poses severe limitation to potato cultivation as a drought-sensitive crop plant. Selection of tolerant genotypes based on a combination of tolerance indices can provide useful criteria for breeding drought tolerant potato varieties. Water deficit affects plants at various levels and stages of their life cycle. This abiotic stress not only affects plant–water relations through the reduction of leaf water content, turgor, and total water, but it also affects stomata closure, limits gas exchange, reduces transpiration, and disturbs photosynthesis. In potato, tolerance to drought is a very complex trait. Photosynthesis is one of the basic physiological processes of plants with internal and external conditions. Any reduction of the intensity of this process causes a decrease in the amount and quality of crop plants. One of the indicators for early prediction of potato yielding can be the measurement of chlorophyll content. It is an informative tool for studying the effects of dif ferent environmental stresses on photosynthesis.  Chlorophyll content has an important role in photosynthesis and in understanding plant functions.  In any research, measuring of the chlorophyll content is used for assessment of potato genotypes tolerant and/or sen sitive to environmental stresses.

In this study, 20 potato genotypes were evaluated under two water levels; normal and water deficit stress conditions. The experiment was performed as spilt-plot based on randomized complete block design with three replications at the Seed and Plant Improvement Institute, Karaj, Iran in 2018. The correlations among the different traits were measured and estimated by calculating Pearson correlation coefficients using the statistical tool in Minitab 17. Tuber yield, yield components, growth parameters, and morphological traits were measured under both well-watered and water stressed treatments. Morphological and reproductive characteristics such as plant height, leaf dry weight, chlorophyll content, yield tuber, ware yield, seed yield, non-marketable yield, and marketable yield were measured. 

Analysis of variance showed that stem number, chlorophyll content, stem thickness, plant height, leaf dry weight (LDW), total yield, ware yield (yield>55 mm), seed yield (yield 35-55 mm), non-marketable yield (yield<35 mm), and marketable yield (ware and seed yield) were significantly affected by genotype and drough and their interaction. Analysis of variance showed that the simple effect of genotype treatment on all studied traits including yield, ware yield, seed yield and marketable yield, LDW, stem thickness, plant height, chlorophyll content, and stem number were significant at 1% level. Correlation of stem number and plant height was highly positive and significant at the 0.01 level. Principal component analysis (PCA) and measured traits showed that genotypes 2, 5, 7 and 13 had high performance in the studied stress environment. To fully reflect the various factors that played a principal role in the comprehensive indicators, PCA was carried out on quantitative traits. The accumulative contribution rate accounted for 99% of the total variation for PC3. Analysis of PCA by the correlation matrix and the biplot analysis methods used in this study revealed that these parameters could be used for evaluating the responses of potato genotypes to water deficit in different environments.  The associations among traits related to yield and genotypes are graphically revealed in a biplot of PC1 and PC2. The PC1 and PC2 axes mainly distinguish the morphological traits and yield-related traits in three different groups.   

Parameters related to yield and leaf photosynthetic pigment content (chlorophyll content) were used to rank the clones and cultivars tested for comparative analysis. Based on our results, genotype 7 performed well under normal and water stress conditions. Water deficit is an important constraint limiting the crop productivity worldwide. Plants show a wide range of responses to water deficit which are mostly expressed by a variety of alterations in the growth and morphology of plants. Field experiments revealed that water deficit affects all evaluated morphological and yield related traits.

Potato (Solanum tuberosum L.) is a global food crop, and Iran with more than 5 million tons of production, ranks 13th among the world’s biggest producers of potatoes. Hamedan province is also one of the main potato producers in Iran. In this crop, the yields of quantity and quality are very dependent on an adequate application of nitrogen. However, the relatively shallow root system of the potato crop, coupled with its large nitrogen and water requirement increases the risk of nitrogen leaching. Therefore, optimizing N consumption for potato is important, both for maximizing production and for minimizing N loss to groundwater. Sustainable agriculture can play a significant role in achieving this goal. One of the methods for achieving sustainable agriculture is to create diversity by using intercropping of different plants in agriculture. Hence, the purpose of this experiment was to evaluate the response of potato as well as the resources use efficiency to intercropping with green bean.

The experiment was conducted as a factorial based on randomized complete block design with three replications in 2016 growing season at the Research Farm of the Bu-Ali Sina University. Planting patterns in four levels (potato sole cropping, planting green bean between potato rows, planting green bean within potato rows, and planting green bean between and within potato rows), and three levels of urea fertilizer (0, 174 and 348 kg urea/ha) were the experimental factors. To calculate the advantages of intercropping, the pure stand of green bean was also cultivated in three replications. In intercropping, 50% of the density of green bean was added to pure stand of potato. Tuber yield, percentage and yield of tubers in different size, leaf chlorophyll content of potato, nitrogen and water use efficiency, as well as total relative yield (RYT) and land equivalent coefficient (LEC) indices were calculated and evaluated. SAS 9.1 software were used for analysis of variance (ANOVA) calculations. The difference between the means was evaluated by the least significant difference (LSD) method at the level of 5% probability.

The interaction of treatments on traits was significant except for the number of main stems and tubers per plant. The highest number and weight of root nodules were obtained from the green bean planting between potato rows with consumption of 174 kg urea/ha, and the lowest values of these were belonged to the green bean planting within potato rows with consumption of 348 kg urea/ha. Also the highest potato leaf chlorophyll was revealed at the green bean planting between potato rows with consumption of 174 kg urea/ha. Maximum total tuber yield and yield of commercial tubers were revealed at the green bean planting between potato rows with consumption of 348 kg urea/ha. However, this treatment did not show a significant difference with the treatment of green bean planting between potato rows at the fertilizer level of 174 kg urea/ha for the traits of total tuber yield and yield of commercial tubers. The highest water and urea fertilizer use efficiency were obtained from the treatment of green bean planting between potato rows at the fertilizer level of 174 kg urea/ha. Maximum RVT and LEC were achieved at green bean planting between potato rows with consumption of 174 kg urea/ha.

Generally, green bean planting between potato rows with consumption of 174 kg urea/ha compare to potato sole cropping with application of 348 kg urea/ha, improved the yield of potato and the efficiency of resources use. Therefore, it seems that this planting pattern is low input agricultural techniques and in addition to the satisfactory production can also reduce nitrogen chemical fertilizer consumption.

Inclusion of cover crops in crop rotations has several benefits such as supplying nitrogen for the next crop. To investigate the effect of cover crops and different levels of nitrogen fertilizer on tuber yield, yield components, and different nitrogen efficiency indices of potato, a filed experiment was conducted as split plots arrangements in randomized complete block design with three replications in 2018-19 and 2019-20 growing seasons at the agricultural research farm of Faculty of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. The main plots was assigned to cover crop at four levels including; rye, vetch, mixed (vetch + rye) and control (no cover crop) and the sub-plots was nitrogen fertilizer application at four levels including; 0 (control), 33, 66, and 100 percent of the recommended fertilizer level based on the soil test. The results showed that treatments had significant effects on tuber yield and yield components, plant height, the number of main stem per plant, nitrogen use indices and tuber nitrate content. Vetch and mixed treatments along with application of 66 percent of nitrogen fertilizer led to the 13 and 8 percent increases in potato yield when compared with application of 100 percent of nitrogen fertilizer without cover crop, respectively. Maximum tuber yield obtained in vetch with application of 66 percent of nitrogen fertilizer (35.42 ton.ha-1) and the least tuber nitrate (31.92 mg.kg-1) wasmeasured in control (without nitrogen fertilizer). Application of nitrogen fertilizer had a significant negative effect on nitrogen use efficiency as the highest nitrogen use efficiency (94.78 kg.kg-1) was obtained by inclusion of vetch as cover crop and without application of nitrogen fertilizer. In conclusion, our findings showed the positive effect of cover crops along with application of optimum level of nitrogen fertilizer on tuber yield potato, plant height and number of main stem per plant. This can be considered as a crop management package that leads to the reduction of application of chemical fertilizers, prevents its adverse effects on environment and more economic benefits for farmers.

The use of biological fertilizers can be effective and beneficial in abiotic environmental stresses specially in drought stress, arid and semi-arid regions of the world.

An experiment was conducted to investigate the effect of deficit irrigation stress and Pseudomonas bacteria on some morpho-physiological traits of two potato cultivars at the research farm of Shahroud University of Technology located in Bastam region in 2010. Treatments included irrigation cycles as the main factor at three levels (7, 10, and 14-days), Pseudomonas bacteria (inoculation and non-inoculation) and cultivar at two levels (Savalan and Agria) as the sub-factor with three replications.

The results showed that the highest dry matter accumulation in the aerial part was observed in the 7-day irrigation cycle and inoculation with Pseudomonas bacteria. The number of tubers was increased about 12.66% because of inoculation with Pseudomonas fluorescens per square meter. Savalan cultivar interaction and 7-day irrigation cycle also obtained the highest number of tubers with an average of 166.39 per square meter. The application of inoculation with Pseudomonas fluorescens increased chlorophyll A by 9.3%. It compared with non-bacterial inoculation. Chlorophyll B had the highest chlorophyll content in the main treatments of the 7-day irrigation cycle and Agria cultivar. The highest amount of potassium content was obtained at the rate of 2.06% at the highest irrigation cycle (14-day). The application of inoculation and non-inoculation with Pseudomonas caused the highest amount of proline at 14-day irrigation cycle. Inoculation with Pseudomonas bacteria increased the final tuber yield about 22.85%. Furthermore, Savalan cultivar increased the final tuber yield about 110.09% in the 7-day irrigation cycle compared to the 14-day. Finally, the 7-day irrigation cycle was the best irrigation cycle to increase the morpho-physiological traits, chlorophyll, number of tubers, and the final tuber yield. Inoculation with Pseudomonas bacteria increased the effectiveness of these traits. Also, the production of compatible osmolytes (proline and potassium) improved drought stress tolerance in 14-day irrigation cycle. Growth-promoting bacteria improves seed germination, root propagation, shoot and root weight, leaf area, chlorophyll content, hydraulic conductivity, protein, nutrient absorption and plant yield (Batool et al., 2020). Growth-promoting bacteria of polysaccharides increases biomass production under drought stress conditions (Daffonchio et al., 2015). Potassium is one of the most important osmolytes under drought stress conditions and adverse conditions (Anschütz et al. 2014). Cellular and physiological responses are carried out through organic salts as proline to reduce cellular damage during drought stress. It is an osmotic regulator (Merwad et al., 2018)

The 7-day irrigation cycle was the best irrigation cycle to increase the morpho-physiological traits, chlorophyll, number of tubers, and the final tuber yield. Inoculation with Pseudomonas bacteria increased the effectiveness of these traits. Also, the production of compatible osmolytes (proline and potassium) improved drought stress tolerance in 14-day irrigation cycle.

In order to investigate the agronomic characteristics of Potato under water deficit stress conditions using line-source sprinkler irrigation method and potassium fertilizer amounts an experiment was done in Khorasan Razavi Agricultural and Natural Resource Research Center during 2015-2016 as split plot design based on completely randomized blocks design. Water deficit levels at 0.75m from line-source (control), at 3.75m from line source (very light), at 6.75m from line-source (light), at 9.75m from line-source (severe deficit), at 12.75m from line source (very severe deficit) were considered as main factor and potassium levels included 0, 90, 180, and 270 kg.ha-1 K2O were as subfactor. Studied traits were included, tuber yield, percent of small, medium and big tuber yield, number of tuber per plant, average of tuber weight, plant height and stem number per plant. The results showed that water deficit stress levels had significant effects on total traits and potassium nutrition levels had same effects except percent of small and medium tuber yield and stem number per plant. Higher water deficit levels significantly decreased the tuber yield, tuber number per plant and average of tuber weight that in very severe deficit these traits reduced 92.29, 84.32, and 53.81 percent respectively. The highest tuber yield (17.92 ton.ha-1), tuber number per plant (7.94) and average of tuber weight (38.73 g) resulted in 270 kg.ha-1 K2O. The highest and lowest tuber yields were in control with 270 kg.ha-1 K2O and very severe deficit with 0 kg.ha-1 K2O.

In order to overcome the contamination problems, as well as the usual method of increasing potato through micro tuber, micropropagation has been considered through tissue culture. The aim of this study was to evaluate the callus induction and embryogenesis in potato cultivars using leaf explants.

For this purpose, micropropagation was performed using leaves from six different potato varieties in different mediums. Seedling of different cultivars in different concentrations of growth regulators, 2,4-D and TDZ showed that the highest amount of callus in 5 mgl-1 of TDZ growth regulator in the culture medium was observed in Batba, Fontane and  Sante. In 12 treatment combinations, the combination of 10 mgl-1 2,4-D and 10 mgl-1 TDZ was performed in leaf explants after three weeks of callus. Then, calluses were tested in a culture medium for embryogenic induction with four different treatments in suspension and solid culture.

In the experiment of embryogenesis study of leaf explants of different cultivars, results showed that explants was placed in a suspension culture of 0.1 mgl-1 Zeatin and 0.1 mgl-1 GA3 and 2.5 mgl-1 BAP and 5 mg/L GA3, and a solid culture medium containing 5 mgl-1 Zeatin and 2.5 mgl-1 BAP and 0.1 mgl-1 Zeatin and 0.1 mgl-1 GA3 had a much better embryogenesis. Among the 12 ‌ treatments applied, the highest callus formation rate was observed in ‌treatment ‌containing 10 mgl-12,4-D and 10 mgl-1 tidiazurone. ‌Results showed in suspension culture medium, 0.1 mgl-1 zeatin and 0.1 mgl-1 gibberellic acid treatment and 2.5 mgl-1 6-benzylaminopurine and 5 mgl-1 gibberellic acid had the highest embryogenesis, but in solid medium, treatment was 5 mgl-1 zeatin and 2.5 mgl-1 6- benzylaminopurine and treatment 0.1 mgl-1 zeatin and 0.1 mgl-1 gibberellic acid have better embryogenesis. Embryos produced in suspension culture medium were coated with calcium alginate and some of them were transferred to solid culture medium for regeneration.

The obtained results showed that it is possible to produce somatic embryos in large quantities in potatoes and these embryos can be used in the production of artificial potato seeds.

In order to investigate the effect of deficit irrigation on vegetative growth characteristics and potato tuber and the effect of foliar application of chitosan and salicylic acid on yield and physiological characteristics of experimental potatoes as a split plot in a randomized complete block design with three replications in 2019 at an agricultural reaearch station in the city of Fariman. Experimental treatments included irrigation levels (60, 80 and 100% water requirement) and foliar application of chitosan and salicylic acid (control treatment, 2 g/l chitosan, 0.5 g/l salicylic acid and combined treatment with chitosan and salicylic acids). Irrigation levels in main plots and foliar spraying treatments were included in sub-treatments. Deficit irrigation treatments were applied 20 days after after plant emergence and at each irrigation period, and foliar application of chitosan and salicylic acid was performed in two stages during the growing season: at the flowering stage (beginning of tuber development), and at the mid-growth stage of tubers. The results showed that by reducing the irrigation volume by 20%, the same performance can be achieved with the performance in full irrigation conditions. Foliar application chitosan and salicylic acid also yielded different results. Foliar application of chitosan prevented a decrease in chlorophyll a concentration as the most important leaf photosynthetic pigment in 80% irrigation treatment. Other pigments showed similar behavior to chlorophyll a in solutions sprayed with chitosan or a combination of chitosan with salicylic acid. Proline, free phenols and soluble carbohydrates as secondary metabolites that undergo stress-induced osmotic regulation of leaf cells also had higher concentrations in chitosan foliar application at 80% irrigation treatment than their control treatment. Foliar application of chitosan and salicylic acid separately or in combination in treatments that were irrigated at 20 and 40% also maintained the concentration of glutathione peroxidase. Despite the above effects, foliar treatments could not clearly have a significant effect on glandular function.It does this by playing an important role in counteracting oxidative stress and balancing oxygen free radicals, as well as its role in protecting cell membranes, especially under stress conditions. According to the results of this experiment, it can be concluded that although these compounds have a significant role in the interaction of potato plant with deficit irrigation conditions, but the time and dose of its use requires more detailed research. Time and dose used that can compensate for the effects of stress and improve yield in deficit irrigation treatments. 

Potato (Solanum tuberosum L.) is one of the most important crops worldwide. It is vegetatively propagated using pieces or whole potato tubers, but a virus infection causes crop reduction to almost a half or even one third, which varies from place to place and from season to another. Micropropagation is the practice of rapidly multiplying stock plant material to produce many progeny plants, using modern plant tissue culture methods. Microtuberization in potato needs the right interaction between several factors such as cyto, sucrose and osmotic stress. The purpose of present study was to investigate microtuberization efficiency of three potato cultivars under osmotic stress and in vitro conditions.

This experiment was carried out based on completely randomized design (CRD) in three replications. Potato seeds of three cultivars (Agria, Savalan and HPS-II/67) were cultured on Murashige and Skoog (MS) medium. After proliferation, plantlets were transferred to the media containing nine treatments with polyethylene glycol hydrogel (PEG) at four levels (0.003, 0.006, 0.009, 0.012 M), sorbitol at four levels (0.1, 0.2, 0.3, and 0.4 M). For this purpose, potato quality, microtuberization percentage, proline concentration, chlorophyll content, and Catalase (CAT) and superoxide dismutase (SOD) activities were measured.

The results showed that plantlets grown under non-stressed conditions (control) possessed higher rates of leaf number, new shoot length and proliferation index compared to the under stressed conditions. Agria cultivar presented better growth characteristics under stressed conditions compared to other experimental cultivars. The highest potato destruction was observed at 0.012 M PEG in Savalan cultivar followed by 0.4 M sorbitol in all cultivars. Microtuberization percentage increased in all three cultivars by stress conditions, in which it increased with progressing in stress levels. The greatest percentage of microtuberization was obtained from Agria cultivar at 0.003 M PEG. Compared to the control, proline concentration, and also CAT and SOD activities increased under stress conditions. Moreover, total chlorophyll content decreased under the stress conditions in comparison to the control.

Generally, based on the results, maximum rates of microtuberization and viability were observed in Agria followed by HPS-II/67, and the highest microtuber weight was obtained in HPS-II/67 cultivar. When plants are faced to stress conditions like osmotic stress, free radicals such as reactive oxygen species (ROS) increases. On the other hand, plants use different strategies to scavenge the generated ROS. The reduction of chlorophyll content and increases of antioxidant enzyme activities are due to increase of ROS under osmotic stress conditions. At slight stress conditions, potato plants utilize the strategy to generate more tuber. Therefore, the lower concentrations of PEG can be introduced as a stimulator of microtuber.

To estimate general and specific combining abilities and heritability in potato genotypes diallel analysis based on Griffing method was used. Reciprocal crosses were made between four commercial potato cultivars; Savalan, Luca, Satina and Caeser parents. For crosses and preliminary tuber seed increase carried out at greenhouse, and main gentypic evaluation trial was performed in field at Alarouq research field station during 2016-2019. There were significant differences between genotypes for tuber yield, tuber number and weight plant-1, main stem number plant-1, plant height, mean of main stem diameter, and tuber dry matter content. General and specific combining ability of tuber yield, tuber weight per plant and plant height were significant. The highest positive and significant general combining abilities for tuber yield, tuber weight plant-1 and main stem number plant-1 belonged to cv. Luca and cv. Savalan. The highest positive and significant specific combining ability for tuber yield was observed for ♂Savalan×♀Luca, ♂Satina×♀Luca, ♂Caeser×♀Luca, ♂Caeser×♀Savalan, ♂Luca×♀Caeser and ♂Savalan×♀Caeser. Tuber yield, tuber weight plant-1, plant height, main stem number plant-1 and tuber dry matter content had higher general heritability.

Anousha cultivar is results of a cross-pollination of Agria and promising colon 397009, and various field and laboratory experiments during 12 years in the Seed and Plant Improvement Institute Karaj, Iran. To release Anousha variety, single plant selection, visual assessment, preliminary and advanced yield trials, adaptability test, study on resistance to fungi, bacteria and viruses was carried out in different places such as Karaj, Ardabil, Hamadan, Esfahan and Mashhad (Jolgehrokh). Although, Anousha cultivar had superiority to the Agria in terms of yield, but scatter Bi-plot analysis with respect to average yield and relative coefficient of excellence showed that its relative coefficient of excellence was almost the same as that of the Agria. The yield of Anousha cultivar in an on-farm study in Hamadan and Ardabil areas was 12.9% and 12.4% higher than that of Agria (check cultivar), respectively. Anousha cultivar is highly resistant to PVY and PVX that are very important and harmful viruses around the world. The reaction of Anousha to Alternaria alternata, Rhizoctonia solani (race AG-3), Rhizoctonia solani (race AG-4) and Rhizoctonia solani (potato black scurf) is semi sensitive, semi tolerant, tolerant and semi tolerant, respectively. The tuber dry matter of Anousha is 2% more than Agria and is excellent for frying and processing purposes. Anousha as a new potato cultivar is suitable for spring cultivation in the cold and moderately cold regions of Iran.

Increased global food production has been associated with increased nitrogen fertilizer application, followed by risks such as nitrate accumulation, water resources pollution, and greenhouse gas emissions. It seems that poultry manure is a suitable case for replacing chemical fertilizers in potato cultivation due to high mineralization rate and micro nutrients. For this reason, two field experiments were carried out based on CRD with 11 treatments in three replications at two sites, Azna and Khoramabad in Lorestan province at 2016 on potato (Banba cultivar). Treatments included nitrogen resource from urea fertilizer and poultry manure along with control. According to results of the experiment, mean tuber yield in Khoramabad (43.7 t.ha-1) was higher than Azna (38.9 t.ha-1). This difference can be attributed to the different growth period in the two locations (Khorramabad and Azna, 114 and 147 days, respectively). Although in both locations, the highest tuber yield was obtained with the application of 700 kg.ha-1 urea, application of 10 t.ha-1 poultry manure resulted in yield approximate to the use of chemical fertilizers, especially in Azna region.However, the results of this experiment showed that agronomic nitrogen use efficiency in urea fertilizer was higher than poultry manure, due to the slight differences in yields between the two types of nitrogen sources, it can be concluded that replacement of chemical fertilizers with organic fertilizers to achieve food security and an efficient and sustainable food chain, is reasonable.