Plant Productions
Year:2016 | Volume:39 | Issue:2|Papers Count:11

Background and Objectives: Dragonhead or Moldavian dragonhead (Dracocephalum moldavica L.), which belong to Lamiaceae family is an annual medicinal herbaceous and aromatic plant that its essential oil is used widely in medicine, food, cosmetic and health industries. Due to the importance and role of medicinal plants in various industries, there is an increasing demand for herbal medicines. The indiscriminate use of chemical fertilizers has increased crop production, but has also harmed ecosystems. Some studies show that the use of some microbial species that are collectively designated as plant growth promoting rhizobacteria (PGPR) can improve yield and quality of medicinal plants. Given the importance of environmental health and food safety, this study aimed to investigate the effect of PGPR on morphological traits and essential oil content of Moldavian dragonhead.Materials and methods: This experiment was conducted in randomized complete block design with eight treatments and three replications at research station of faculty of agriculture, Shahrekord university. No bacterial inoculation was used as control and seeds inoculated with Rhodococcus sp., Corynebacterium sp., Mycobacterium sp., Bacillus sp., Azotobacter sp., Pseudomonas putida, Pseudomonas fluorescens were considered as bacterial treatments.Results: The results showed that all bacterial treatments had a significant effect on plant height, number of branches, number of flowering shoot, leaf dry weight, shoot dry weight, biological yield, crop growth rate (CGR), leaf area (LA), chlorophyll a, chlorophyll b, essential oil content and yield. Mycobacterium sp. treatment had the most effect on plant height, number of branches, leaf and shoot dry weight, number of flowering shoot, biomass and chlorophyll b. Bacillus sp. treatment had the most effect on leaf dry weight, number of flowering shoot, leaf area and essential oil content and yield. The highest crop growth rate and chlorophyll a were observed in Rhodococcus sp.treatment.Discussion: In general, the Bacillus sp., Mycobacteriumsp., Rhodococcus sp., andPseudomonas putida treatments had the most influence on Moldavian dragonhead. Since the purpose of medicinal production is obtaining the highest content of essential oil and biomass yield, based on these results, the use of Bacillus sp., and Mycobacterium sp., bacterial inoculation treatments, as biopriming, can be recommended for increasing biomass and essential oil content in Moldavian dragonhead.

In order to study the effect of different green manure crops on soil fertilization and weed population a field experiment was conducted in experimental farm of Agricultural Faculty of ShahidChamran University of Ahvaz at 2013-2014 growing season. Experimental design was randomized complete block design with three replications. The treatments include different greenmanure crops including Millet, Barley, mungbean, intercropping of millet and mung bean and fallow (without green manure application). The millet mungbean intercropping treatment had the highest (2168 kg/ha) and barley green manure (387.4 kg/ha) had the lowest biomass production. The results showed that the Intercropping, Mungbean, Millet and Barley reduced weed biomass compared to control by 43, 38, 36 and 15% respectively. Also, the mentioned treatments decreased weed density by 57, 35, 33 and 6% respectively. The highest soil organic matter (1.41%) was obtained at intercropping of Millet and Mungbean treatment. In order to nitrogen fixation by legums, the Mungbean green manure had highest soil nitrogen percent (0.082%). The highest potassium content(168 mg/kg) was obtained at intercropping of Millet and Mungbean treatment but there was no significant difference between mungbean, millet and intercropping. Also, the highest phosphorus content (12.3 mg/kg) was related to mungbeangreenmanure treatment but there was no significant difference with intercropping treatment.

Background and Objectives: Wheat (Triticum aestivum L.) is one of the most widely cultivated crops in rainfed areas of Iran where drought is the main limiting factor of production. Yield in drought-prone environments may be considered to be affected by three factors including yield potential, appropriate phenology and drought tolerance. Despite the positive correlation between grain yield in drought stress and normal conditions indirect selection based on yield potential, mean yield under non-stress conditions may not give the best results for selection of drought tolerant genotypes. Grain yield is strongly affected with genotype by environmental interaction. On the other hand, this interaction is relatively small for secondary traits. Hence, evaluation of genetic control of yield and yield related traits was the main objective of the present study.Materials and methods: In order to estimate genetic parameters of yield and its related traits in bread wheat, a half diallel mating design was generated using nine (9) cultivars including Mahdavi, Azar2, Roushan, Ghods, Kavir, Excalibur, Shiraz, Kalhaydari, Shiraz and Shahpasand, and their F2 progenies. For this purpose, genotypes were planted in a Randomized Complete Block (RCB) design under normal and drought stress conditions. Plant height (cm), awn length (cm), biomass (t/ha), grain number per spike, fertile tiller number, days to flowering (days), grain filling period and grain yield (t/ha) were evaluated in this research. Hayman and Jinksdeiallel method was used to estimate genetic parameters including additive and dominant variance. In addition, variances of general and specific combining ability were estimated using Griffingmethod.Results: Analysis of variance showed significant genotypic variation for all traits. Diallel analysis indicated that both additive and non-additive effects were valuable for genetic control of most characters. Awn length and days to flowering had the highest narrow sense heritability. Narrow sense heritability of grain yield under normal conditions was significantly higher than drought stress conditions. Plant height and awn length in both conditions and grain number per spike under drought stress condition were identified as the most appropriate traits in wheat breeding programs. These traits had high narrow sense heritability and low non-additive effects.Discussion: Genetic analysis of evaluated traits showed that non-additive effects played a significant role in genetic control of the most characters. Based on these results, bulk and single seed descent are recommended methods for breeding in this population even though, awn length and days to flowering showed high narrow sense heritability.

Background and Objectives: In Iran, about half of the sugar beet fields are infected by Rhizomania disease and the severity of infection in various regions is different. Then the selection of appropriate varieties which could have high yields in different infected conditions is important.Material and method: To compare promised resistant hybrids to rhizomania in different conditions of infection to the disease levels, an experiment was conducted in four regions including disease free and infected areas with different infection levels. In the this study, 19 monogerm diploid hybrids resistant to rhizomania were compared with foreign and domestic resistant varieties in randomized complete block design with four replications. In the disease free location, the percentage of seedlings emergence in domestic genotypes relative to the average of foreign resistance varieties, leaf number, leaf arrangement, green intensity and uniformity of crops were determined in the early growing season. At the harvest time in infected areas, the disease severity index was determined. In all areas, number, yield and quality of roots in each treatment were measured.Results: Results confirmed that disease intensity of experimental regions was different. There was a significant variation among promising hybrids in the investigated properties. Discussion: Generally, with increasing disease severity, root number, root yield, sugar yield, sugar content and nitrogen of roots were significantly reduced. In contrast, the gross amount of sodium and potassium increased in roots. Hybrid SB26 because of high root numbers, root yield, sugar content and sugar yield and low sodium content of root as well as low disease severity was chosen as a superior hybrid. The results of this study confirmed that also in condition of disease free, a resistant variety has better quantitative and qualitative characteristics in comparison to a susceptible variety.

Background and Objectives: Correct crop rotations selection and suitable tillage systems, and also considering the interaction of these two factors play an important role on the yield crops, especially wheat. Conservation tillage methods, considering the resource use efficiency in crop rotation (instead of efficiency of a single crop), are the focus of sustainable agriculture. The proper balance of nutrients in the soil, increase of soil organic carbon, prevention of erosion, prevention of soil compaction, improving soil structure, reducing weeds and increasing soil water holding capacity are the beneficial effects of the proper crop rotations and suitable tillage systems.Material and Methods: A three year study (2011-2013) was carried out in the agricultural research station of Ardestan city located in 125 km North East of Isfahan (32o 50' N and 50o 34' E) using split plot, based on a randomized complete block design with three replications. Conventional tillage systems (moldboard plow), minimum tillage (a field cultivator) and no-tillage were the main plots and rotations of (Barley - corn - wheat), (Canola - sunflower - wheat), (Fallow - sugar beet - wheat), (Wheat - fallow - wheat), (Canola - fallow - wheat) and (Canola - corn - wheat) were the sub-plots. Comparison of the yield of wheat in different rotations was made in the last year rotation.Results: The results showed that wheat yield in conventional tillage and minimum tillage techniques was equal with 4531 and 4340 kg ha-1, respectively, being 33.8 and 28.1% more than the no-till method. In conventional tillage systems, yield of wheat in (barley - corn - wheat) and (canola - corn - wheat) rotations were equal to 4129 and 4118 kg ha-1. In the no tillage system, small canary grass (Phalaris spp) with 1485 kg ha-1 dry weight significantly produced more dry matter than the other two systems. Among the rotations (Canola - sunflower - wheat) rotation, with 1.05 kg m-3 and 52.6 percent water productivity index and land use efficiency, respectively, was one of the best rotations.Discussion: Effect of tillage system depends on the type of crop rotation, soil type and climatic conditions. Successful adoption of no-tillage system (compared to conventional tillage) is more probable in cases where crops used in rotation with fast decomposed remnants (e.g. potatoes) improve soil conditions (e.g. sugar beet) or control weeds (e.g. sunflower).

Background and Objectives: Statistical parameters can be used in plant research to elucidate the differences in growth behavior among traits in a plant population.Materials and Methods: In order to examine the relationships between plant characters, seed yield and yield related trait 14 lentil genotypes were planted as a randomized complet block design with three replications to assess plant growth under rain fed at Gachsaran dryland agricultural research station, Iran.Results: Based on regression analysis using stepwise method, number of pods per plant, chlorophyll content, and 100 seed weight entered the model and explained 89.3% of the variation in the seed yield. In order to determine the direct and indirect effects of traits on seed yield, path analysis was performed and number of pods per plant, chlorophyll content and 100 seed weight showed the highest positive direct effect on seed yield, respectively.Discussion: Deployment of statistical approaches to assess lentil genotypes under rainfed conditions indicated that there is a positive correlation with seed yield, plant height and number of pods per plant. It also that as soil moisture remained at the minimum range during reproductive growth, the quality performance of these plant traits was significantly enhanced in some genotypes. Such variations are primary sources that can be incorporated into desirable cultivar through hybridization.

Background and Objectives: Micropropagation is the best approach to propagation of Fritillaria and prevention of its extinction. The effects of auxin and cytokinin combinations on callus and bulbletproduction using explants taken from daughterbulb scale of two fritillary clones collected from Arjan and Koohrang plains of Fars province were studied.Materials and methods: For this purpose, 3 types of growth regulator combinations containing three levels of NAA (0, 0.5 and 1.0 mg L-1) with one of the cytokines (2ip, Kinetin and TDZ) at three levels (0.5, 1.0 and 2.0 mg L-1) were applied. The base medium was MS containing 4.5 percent sucrose and 8 g/l agar. To evaluate the effects of these factors, an experimental design of completely randomized factorial with 4 replications and 5 explants per repeat was used.Results: Analysis of data revealed that the kinetin and 2ip had no significant effect on callus induction percentage while TDZ was significant on this parameter. The highest callus production was observed in medium containing 0.5 mg L-1 NAA combined with 0.5 mg L-1 TDZ. Using this treatment, 60 percent of explants produced the callus. The most number of direct and indirect regenerated bulblets were recorded in medium complemented with 1.0 mg/l NAA and 1.0 mg L-1 Kinetin. The mean of 5.5 bulbletper explants was obtained in this treatment.Discussion: Considering the effectiveness and cost of NAA and environmental issues, its lower concentration is recommended for bulblet regeneration in this plant.

Background and Objectives: Ber (Ziziphus spp.) is one of the most ancient fruits indigenous to India and grows in tropical, subtropical and dry areas of the world. Growing of commercial cultivars of ber is common in many countries. Some of such cultivars originated in India and Pakistan, have been cultivated in the south part of Baluchestan region since several years ago. However, there is very little information about adaptability and fruit quantitative and qualitative characteristics of these cultivars. Thus, conducting the present research was deemed necessary. The objectives of this research were to evaluate vegetaitive growth and fruit properties of six superior Ber cultivars in Baluchestan.Materials and methods: In the first phase of the research (2006-2011), vegetative growth of six superior ber cultivars existing in Baluchestan were studied in a complete randomized block design, with four replications and three plants per replication at Tropical Fruits Research Station in Chabahar district. The cultivars were Behzadi, Farzadi, Hanifi, Soopi, Sibi Seyah and Sibi Sefid. One season after budding, vegetative growth, length of main branch, trunk diameter at lower part and upper part of budding were measured. Fruit morphological chractristics including fruit weight, length, diameter, fruit shape, seed weight and fruit pulp were evaluated at the harvest time. Statistical analysis was performed with MSTAT-C software and the means were compared using Duncan's Multiple Range Test.Results: The results showed that all these cultivars have good vegetative growth in this region and significant differences in vegetative growth indexes were observed between different cultivars.  Maximum longitudinal growth of main branch during the growth season (200 cm), diameters of main branch at the lower part (38.8 mm) and at the upper part of budding position (38.1 mm) were observed on Hanifi ber cultivars. Although plants still did not reach economic bearing age, there was a significant difference among cultivars in some fruit characteristics including fruit weight, length, diameter and shape, stone weight and fruit pulp percentage.Discussion: Based on the obtained results from the present study can be concluded that, all sex ber cultivars had good adaptibility in the Chabahar climate. Most fruit morphological chractristics of different ber cultivars in the current research, were in the range accomplished by previous studies. However, final recommendations will be achieved after the plants reach to the economic bearing age.

Background and Objectives: RNA extraction is considered a crucial step in the molecular studies and the results of subsequent work such as, PCR, Real-TIME PCR and RACE PCR depend on the quality and quantity of the extracted RNA. Some standard methods are available in total RNA extraction of plant tissue, which are effective for the ordinary plants. But it is difficult to extract the total RNA from the plants with high levels of carbohydrates and secondary metabolites such as phenolic compounds. Yarrow is one of the valuable medicinal and industrial species of the pasture of Iran that contains high levels of secondary metabolites. So far, there is no report on a suitable method for extraction of total RNA from it. Material and Methods: Total RNA extraction was done through three methods including RNXTM (-Plus), Lithium Chloride and Phenol-Chloroform. Then the quality and quantity of extraction RNA was evaluated.Results: The results showed that among the three methods, extracted RNA with phenol-chloroform had high quantity and quality as the A 260/280 ratio was well within the accepted range of 1.8-2.Discussion: Using phenol-chloroform method tends to remove polyphenols and polysaccharides from plant tissue cell contents and causes more efficient RNA extraction. Given of this, the phenol-chloroform method is recommended for total RNA extraction of valuable plant Yarrow in future studies.

Background and Objectives: As on of the world's arid and semiarid climate regions, Iran suffers from two major problems of soil and irrigation water quality in agriculture of arid regions. The first and most critical step of plant growth and development is germination; in addition, the uniformity of germination, average time of germination and emergence are also important parameters in seed quality. One of the new techniques in this regard the use of seed pretreatment that is generally referred to as priming. The aim of this study was to investigate the effect of water quality on yield and yield components of two sesame genotypes and determine the genotypes that adapt themselves quickly to changing circumstances of priming and water quality.Material and methods In order to study the effects of water quality, priming and genotypes on yield and yield components of sesame, a field experiment as split plot factorial based on RCBD with three replications was conducted in Dashtestan of Bushehr province in 2013. The main plot involves two measures of water quality (the first by the EC: 3.4 ds/m, soluble salts: 2.14 g/l, pH: 7.7, calcium and sodium: 560 and 276 ppm, and the second by the EC: 0.601 ds/m, soluble salts: 0.33 g/l, pH: 7.4 and calcium and sodium: 96 and 23 ppm) and the sub-plot consisted of factorial arrangement of genotypes (Dashtestan 2 and Line 5) and priming (salicylic acid in 25 and 50 mg per liter and NaCl in 5 and 10 grams per liter and hydro priming as a control). Ultimately, the grain yield, oil yield, yield components, length and weight of were measured capsules. Result: The results showed that water quality, genotypes and priming interactions caused different changes in yield and yield components. The best genotypes and priming for number of branch, number of capsules per plant, capsule dry weight, thousand seed weight and grain yield belong to the Dashtestan 2 genotype and priming with salicylic acid in 25 mg per liter at the first water quality. Applying a second water quality led to reduction in the number of capsules, thousand seed weight and grain yield. It seems that Dashtestan 2 among the studied genotypes in the first water quality condition, with the highest grain yield, oil and yield components showed the highest rate of compliance with the experimental conditions.Discussion: The two genotypes of sesame were different in saline conditions in terms of capsule manufacturing per plant. It seems that the salinity may limit and disrupt the balance in nutrient uptake by the roots, resulting in the production and allocation of assimilates to reproductive organs, such as decrease of the components, and reproductive organs; the salt may lead to the loss of the number of capsules per plant. In general, it seems that the number of capsules per plant of sesame ecotypes has genetic diversity and this feature can be used in breeding programs. Beneficial effects of salicylic acid on grain yield in relation to the transfer of photosynthesis assimilate in grains during grain filling that is a result of increased grain weight.