جستجوی مقالات مرتبط با کلیدواژه « Stem Length » در نشریات گروه « کشاورزی »

Salinity is among the abiotic stresses restricts citrus growth. In this regard, the selection of appropriate method to improve growth characteristics and antioxidant response under salt stress conditions can be useful. The present pot research was conducted as factorial reperiment in a completely randomized design with three replications in the greenhouse of University of Hormozgan during 2021. The used lime plants were six-month-old seedlings (height about 60 cm) healthy and disease-free. Experimental treatments were included salinity (1.5, 3, 4.5, and 6 dS/m) and potassium phosphite (0, 1.5, and 3 g L-1). The results revealed the 6 dS/m of salt led to a decrease in leaf number, stem length and root volume (25.27, 13.8 and 47.8% respectively) and increased ion leakage and malondialdehyde (50.47 and 34.5%, respectively). Application of potassium phosphite (1.5 g L-1) increased leaf number, stem length, root volume and root length (33.87%, 32.38%, 15.5% and 11.05%, respectively). In addition, the potassium phosphite treatment increased protein content and activity of catalase, superoxide dismutase, phenylalanine ammonialyase, guaiacol peroxidase and ascorbic peroxidase (36.9, 95.97, 69.1, 30.20, 65.7 and 78.5%, respectively) and decreased ion leakage and malondialdehyde (75.7% and 40.6%, respectively). Based on the results, it can be expected that potassium phosphite (1.5 g L-1) by stimulating the antioxidant system and neutralized oxygen free radicals, improves growth characteristics and moderates the harmful effects of salinity stress in lime.

Medicinal plants are one of the rich sources of important compounds from ancient to the present; it has found a special place in the treatment of many diseases and has become an important reason for many studies on medicinal plants. On the other hand, the diversity of plants has led researchers to use morphological markers first and then cytogenetic markers to select the physiologically and genetically superior plant. Peppermint (Mentha piperita) from Lamiaceae family is one of the most important medicinal plants, used in food, sanitary and cosmetic industries and used as a spice and traditional herb in Iran. The purpose of the experiment is to investigate genetic diversity based on morphological diversity.

In this research, different accessions of this plant were collected from different regions of Iran. An experiment was conducted in 2021 year based on randomized complete block design to evaluate the morphological of these accessions in Meshginshahr climatic condition. The results were analyzed using spss software and univariate and multivariate statistical methods.

Analysis of variance showed that there were significant differences for the most studied traits among 12 accessions. The important traits such as plant height, branch number, leaf number traits, the internode length, in inflorescence length, the plant dry weight, plant fresh weight, bracket number, stem length, , internode number, bract number, Plant diameter, Dry weight leaf, Dry weight flower, Leaf surface and Flower number per plant were varied among accessions. The Meshginshahr, Golestan ,Ardabil and Urmia were the best in phytochemical. Maximum correlation was shown between plant height and stem length (0.97). Cluster analysis, classified the accessions into three  major claddes. Factor analysis indicated that the four factors explained 91.3 of the variability among the accessions. The results of path analysis showed that the leaf number and  plant dry weight content had highest direct and positive effect (0.75).

The results suggested that there was a considerable genetic variation among M. piperita L accessions. Indicate the presence of comparable genetic potentials in genotypes of Mentha piperita L. for cultivar development.

Salinity stress is one of the most important factors in decreasing crop yield. Crossing between cultivars and wild relatives is one of the methods to creating salinity tolerant plants that has led to the creation of new Tritipyrum cereals. Investigation of the effect of salinity stress at the germination stage is a reliable test in assessing salinity tolerance of many species; it reduces percentage and rate germination as well as decreases of root and shoots growth. This research aims to investigate the effects of different levels of salinity stress on germination of promising non-Iranian Tritipyrum lines and two wheat cultivars, Alvand (salinity tolerant) and Ghods (salinity sensitive).

The experiment was conducted in factorial based on the completely randomized design at the Faculty of Agriculture, Yasouj University. The first factor consisted of 13 Tritipyrum lines and two wheat cultivars and the second factor consisted of different salinity levels (240, 160, 80, 0 mM NaCl). After surface disinfection and seed culture in a petri dish, germination-related traits were measured until the 14th day.

The results showed that by increasing salinity level, germination rate and percentage, root length, shoot length, dry and fresh root weight, and shoot dry weight decreased. The highest percentage (79.79%) and rate (75.74 seed per day) of germination in stress and non-stress conditions were related to the Az/b line. The germination percentage of the Alvand tolerant cultivar (55.59%) was higher than 5 Tritipyrum lines but less than the other 7 lines, its germination rate (53.69 seed per day) was higher than 10 Tritipyrum lines. The percentage and germination rate of sensitive cultivar Ghods (40.98 and 36.87 seed per day, respectively) were lower than all Tritipyrum lines. Under salinity stress, the La/b line had the highest root length (7.77 cm) which was even longer than the root length of the Alvand tolerant cultivar (4.9 cm). The highest root dry weight (0.027 g) under stress conditions was related to the Ka/b line and the lowest root dry weight (0.013 cm) was related to the Ghods cultivar. Among germination traits, the highest and the lowest heritability were related to shoot length under stress and non-stress conditions and root fresh weight (under non-stress conditions) and root length (under stress conditions), respectively. Genetic variance of shoot length and germination percentage in non-stress conditions was higher than stress conditions and selection under non-stress conditions had a higher yield than stress conditions. Clustering of genotypes by cluster analysis divided the genotypes into four groups under normal and salinity conditions. Under salinity stress, the salt-tolerant cultivar was placed alone in the fourth cluster. The salinity-sensitive cultivar was also in the third cluster with the St/b line. The rest of the Tritipyrum lines were clustered in the first and second clusters, with (Ka/b)(Cr/b)F6 hybrid line in the first cluster. Salt stress condition seems to have separated Qods from all Tritipyrum lines (except St/b), but under normal conditions, it did not indicate clustering accuracy of the studied genotypes.

The results of this study demonstrated salinity tolerance in the most simple and hybrid lines of this plant at the germination stage, among them (St/b)(Cr/b)F3, (Ka/b)(Cr/b)F6, and (Ka/b)(Cr/b)F3 and La(4B/4D)×(b) and the simple lines La/b, Az/b and St/b were better than others. Therefore, these selected lines can be considered in further complementary studies.

Control of bacterial diseases is one of the problems in agricultural products, specially greenhouses. In this study, the effect of compost and vermicompost fertilizers and their tea on tomato plants infected with bacterial vascular wilt caused by Ralstonia solanacearum in greenhouse conditions was investigated based on a factorial experiment with a completely randomized design including four types of compost fertilizers, in four concentrations (zero, 20, 30 and 40% by volume). Bacterial suspension with concentration of 108 CFU / mL was added to pot soil at two to three leaf stage of seedlings. The percentage of disease incidence and growth index changes in treatments were compared Took. The results showed that most of the treatments inhibited the disease compared to the control inoculated with bacteria, but the highest rate of disease control was obtained in treatments containing vermicompost with a concentration of 40 and 30% by volume, respectively 66.67% and 60.0%. In the substrate containing 30% by volume of vermicompost tea, the severity of disease decreased by 53.33%. In plants inoculated with bacteria, the best growth indices were obtained in substrates containing vermicompost, compost and vermicompost tea with a concentration of 40% and also compost tea with a concentration of 30%.

This experiment was conducted in a factorial arrangement in a completely randomized design with three replications. 24 canola genotypes (13 varieties and 11 double haploid lines) at four levels of soil moisture including 80, 50, 30 and 20% field capacity (FC) were evaluated in pots in the greenhouse of seed and plant improvement Institute in Karaj during 2017. The growth of the shoot was more affected by different levels of soil moisture in comparison to the root growth that indicating a greater sensitivity of the stem length compared to the root length in response to the low water stress. Therefore, the root-shoot ratio can be an appropriate index for assessing the water stress tolerance. The results showed that cultivars such as Oase, Triangle, Tassilo and Savanah, had very high stability under stress conditions, but due to small amounts of the first and second components, they were classified as susceptible to water deficit stress. Also, SLM046 and Billy had the least stability in traits under water deficit stress at germination stage. Due to the non-separation of the three levels of soil moisture (80%, 50% and 30% FC), were not suitable for selection and only 20% FC was identified as the appropriate condition for selecting the ideal genotype. Therefore, between genotypes that were located in a 20% FC, based on the 'which-won-where' pattern, GKH 2005 was identified as the superior genotype.

Flower stem length is highly important in cut roses. One of the Richard’s function application is estimating growth behavior of plants. Four cultivars of cut roses have been selected in a commercial greenhouse then were subjected to stem length measurement upon producing a new node. Data was first fitted to the nearest form of curve, i.e., quadratic model. Coefficient of determination was calculated between 0.95 and 0.98 for this model. Thereafter, data transformation was done by dividing each value by the maximum value in the measured data. Richard’s function was then fitted to the data which gave rise to R2 value of more than 0.99 for most cultivars. To estimate model parameters for all curves of cultivars in two seasons we used nonlinear least square regression. The cultivar ‘Black Magic’ showed the highest rate of curve slope in inflection point, however the curve slope for spring season was appeared to be more than the summer slope. First derivative of the Richard’s function was used to calculate the relative stem growth rate. Results indicated higher rate of relative growth rate for spring stems rather than summer stems. Spring stems showed their highest relative growth rate in eighth and ninth node while this happened for summer stems in nodes of five and six. Estimation of stem final length was done by 10 cm difference from the measured value in fourth node onwards and about 5 cm difference in nodes followed by node 8.

An experiment was conducted as split plot based on the randomized complete blocks design, in greenhouse complex of Shahid Chamran University of Ahvaz in 2017. The main plot consisted of light treatment at two levels [a) sunlight (control), b) sunlight + red and blue LEDs (50:50%) with light intensity of 70 μmol/m2s for 15 hours (from 5 PM to 8 AM as night light] and the subplot was six greenhouse lettuce cultivars (Black Seed Simpson, Green Ice, Vivian, Tom Thumb, Red Salad Bowl and Salad Bowl). Results of the experiment showed that some of the measured traits were influenced by cultivar and light increase and some of them were under the influence of interaction effects of cultivar and light and were significant at 1% level. Maximum fresh and dry weight of leaf, fresh and dry weight of stem, number of leaves and calcium content were observed in night light treatment. Maximum and minimum values of leaf nitrate content were observed in Tom Thumb cultivar and control treatment (1723 μg/g dry weight) and Green Ice cultivar and night light (1023 μg/g dry weight), respectively. Maximum and minimum values of calcium content were observed in Black Seed Simpson cultivar and night light (1477 μg/g dry weight) and Tom Thumb control treatment (271.1 μg/g dry weight), respectively. According to the results of this experiment, by increasing the night light, it is possible to enhance the quantitive growth of the leafy lettuce cultivars by 90%, and also increase the quality of their yield

In order to evaluate the effect of drought stress on corn germination indices produced under drought stress on a parent plant, experiment was conducted in a completely randomized design with three replications in a Bahar university in 2017. The factors applied to the mother plant were: full irrigation as control (R1), full flowering stage (R2), pod closure (R3), pod filling (R4), seed start (R5), and complete seeding (R6). The results showed that the highest germination percentage, root length, stem length and dry weight of soybean seedlings were obtained in irrigation treatments throughout the plant life (control). No significant difference was observed between the treatments in the traits and the mean germination time. The lowest dry weight was obtained in drought stress at full flowering stage. Drought stress had an impact on the traits studied and it is recommended that soybeans, especially at full flowering stage, do not undergo drought stress.

The present study examined the separate and collective impacts of using compost and solarization on tomato (Lycopersicumesculentum). Tomato cultivation area was solarized for 14 hours a day over a 2 months period in order to increase the soil temperature beyond 60 degree Centigrade. At the end of this period, the compost which was created using different strategies was added into the 20 cm depth of the soil. The purpose of solarization in this experiment was removing weeds and pests in an attempt to decrease the competitive ability and increase the fruit growth, plant germination, and photosynthesis in a randomized complete block factorial design. Accordingly, by removing the weeds, the amount of shadowing on the plant was decreased and this increased the photosynthesis. The purpose for using compost was increasing the growth and nutritional abilities of the plants by means of the organic materials. In other words, the overall purpose was operationalizing an experiment in an organic farm. The results indicated that the fruit weigh significantly increased. The plant yield also increased up to 37% which can be attributed to the removing of the weeds by means of solarization. This way, the weed shadowing is removed and due to the absence of another weed, there is no competition between the plant and the weed. Using compost significantly increased the photosynthesis and plant growth. The existence of nutrients, organic materials, and organisms such as ectinomisets and protozas, which enhance the stabilization process, made the soil nutritious. Destruction of pathogens can be considered as one of the significant aspects in the process of producing compost. The process of producing compost and its collective function with solarization omitted pathogens.

Tree increment has been under the influence of internal factors and external different factors. Throughout life, growth rates will vary depending on how the impact of these factors. Because the diameter growth, has fluctuations, at different heights in the stem. The aim of this study is to investigate the fluctuations of Pinus brutia diameter growth during the stem is done. For this purpose, the number of 31 pine trees were randomly selected and cut. Then from each tree, 5discs, from the different heights of the tree stem were taken. After preparing disks, annual rings width, using software COREL DRAW X5 and the accuracy of 0.001mm was measured. The mean diameter growth of trees in each height and stem length was analyzed using ANOVA and Duncans. The multiple range tests showed that the amount of diameter growth of this species is meaningful at different altitude sand in the mean Duncan regimentation are not in a group. The maximum diameter and basal area increment, throughout the stem, respectively was measured by 0.7 of tree high (from the ground) and stump height. Also, based on the analysis of growth curves, absolute age for the utilization of this stand, at the age of 20, was determined.

One of the important issues in the arid and semi-arid regions is the soil salinity and drought. Therefore, choosing resistant species to salinity and drought especially in seed germination and emergence stages is important. This study investigated the effects of salt and drought stress on seed germination of Stipa arabica which is as palatable forage. We measured the percentage of germination, germination rate, stem and root length, seed vigor under salinity and drought stress. A completely randomised design was carried out using six salinity treatments (control, 50, 100, 150, 200 and 300 mM NaCl) and six drought treatments (control, 0.2, 0.4, 0.6, 0.8 and 1 MPa polyethylene glycol). For each treatment we used 25 seeds as replicate in Petri dish and then were germinated in gerrminator for two weeks. Results showed that salinity stress significatly influenced seed germination and as a result we found a significat reduction of percentage of seed germination, seed germination rate, stem and root length and seed vigor.

One of the most important goals of sugar beet cultivation is to achieve high seedling emergence and establishment under water deficit conditions. In this experiment irrigation of the seed bearing plants was cutoff in four periods of 750, 1000, 1250 and 1500 GDD after schtechlings were planted and the seeds were formed and grown under water stress. The experiment was carried out as a randomized complete block design with four replications. All treatments were harvested simultaneously and seed yield and seed physical quality characters were determined. In the second step, germination qualities of treatments were determined under 0 and -12 bar osmotic potential in four replicates. Results showed that seed yield of the last irrigation cutoff (1500 GDD) was 7 times more than that yield of the first irrigation cutoff (750 GDD). Standard seed size and germination were increased by postponing irrigation cutoff. Root length was affected more than stem length by the irrigation cutoff time so that, postponing irrigation cutoff up to days before harvest root and stem length 13 and 50%, respectively.

Allelopathic compounds display an important role in biodiversity، stability and ability of ecosystems production. This phenomenon that has not been considered in range improvement is of important concerns in restoration of rangelands. Artemisia aucheri due to having chemical properties may contain allelochemical components. In this study، allelopathic effect of mentioned species was tested on Festuca arundinacea and Dactylis glomerata of seed germination. To do so، aerial part powder of Artemisia aucheri (stem، leaf and seed) collected from habitats in flowering stage (end of November). Also a control treatment (distilled water) was used. A completely randomised design was carried out using six treatments and four replications in laboratory. Results showed a significant effect of aqueous extract of Artemisia aucheri on seed germination indices. The percentage of germination، seed germination rate and plumule and radicle length، and seed vigor of Festuca arundinacea، and Dactylis glomerata significantly reduced under aqueous extract of Artemisia aucheri.