جستجوی مقالات مرتبط با کلیدواژه « کاملینا » در نشریات گروه « آب و خاک »

Soil salinity, especially in arid and semi-arid regions, is one of the factors that limit the growth of plants. Excessive accumulation of sodium and chloride ions leads to reduced growth and imbalance of nutrients. The use of exogenous polyamines, including putrescine, spermidine and spermine, is considered as an effective method not only in determining their role in response to salinity, but also as a way to increase plant resistance to salinity. Camelina is an oilseed product of the Brassica family, which contains other bioactive compounds such as flavonoids and phenolic products and as a new source of essential fatty acids, especially omega-3 fatty acids. This study was conducted with the aim of evaluating the effect of different levels of sodium chloride and foliar spraying of spermine, spermidine and putrescine on seed yield and the concentration of leaf and root nutrients in Camelina plant. The experiment was carried out in March 2022 as factorial design based on a completely random design (CRD) in the form of pot culture with 12 treatments and 3 replications. The salinity stress treatment was with Urmia lake water at three levels (0, 15, 30 ds/m). Foliar treatment at 4 levels 1- Foliar spraying with spermine (2 mM), 2- Foliar spraying with spermidine (2 mM), 3- Foliar spraying with putrescine (2 mM) and control (no foliar spraying). The application time of foliar spraying was done every 3 days (totally in 6 stages) after establishing three seedlings in the pot and reaching the four-leaf stage. At the end of the Camelina plant growth season, to calculate the seed yield, the seeds in the capsules of three plants in each pot were separated and weighed. Statistical analysis of data was done using SAS software (version 9.1) and MATATC, and comparison of means was also done by Tukey's test at the five percent level. Excel program was also used to draw graphs. The results of this research showed that the salt stress was 30 and 15 ds/m compared to the treatment without salt decreased leaf potassium (52 and 17%), root potassium (44 and 37%), leaf magnesium (50 and 28%), root magnesium (56 and 24%), leaf zinc (58 and 47%), root zinc (39 and 29%), leaf iron (10 and 2%), root iron (57 and 23%) and seed yield (52 and 10%), but it increased the amount of leaf sodium (89 and 82%), root sodium (39 and 11%), leaf calcium (14 and 6%) and root calcium (76 and 28%), respectively. Also, salinity stress caused a decrease in the ratio of potassium to sodium absorption, but increased the ratio of calcium to the sum of sodium and potassium in the roots and leaves due to the increase in the amount of sodium and the decrease in potassium. At all salinity levels, foliar spraying with polyamines increased leaf and root potassium, leaf and root magnesium, leaf and root zinc, leaf and root iron, by reducing the amount of sodium in leaves and roots. Also, foliar spraying with spermine, spermidine and putrescine compared to no foliar spraying, increased the seed yield by 32, 8 and 21%, respectively. The results of this research showed that foliar spraying with spermine, spermidine and putrescine by improving the absorption of macro and micro elements in roots and leaves, increasing the ratio of potassium to sodium and the ratio of calcium to total sodium and potassium in roots and leaves could moderate the effects of salinity stress and improve the seed yield of camellia under salinity stress conditions and it prevented excessive reduction in seed yield.

At present, oilseeds are of great importance among crops and constitute the second largest food reserves in the world after cereals, so the need for new oil products with more adaptation and less needs is strongly felt. Plants are exposed to various stresses during their growth period, and water shortage is the biggest challenge in crop production, especially in arid and semi-arid regions of the world, including Iran; Also, planting date has a great impact on production and the amount of crops. Camellina is an annual shrub and the most important oilseed in the United States and South Asia.Due to the importance of this plant, during a one-year experimental design, it was performed as a factorial experiment in a completely randomized design with three replications. The treatments were irrigation and planting date. Irrigation treatments (50, 75, 100% of full irrigation and rainfeed) and a planting date (February 19) were performed in the research farm of the Department of Water Engineering, Agricultural College, Shiraz University. The highest amount of seed yield and Shoot dry matter was observed in full irrigation treatment, the amount of harvest index in different irrigation treatments was not significantly different. Its amount was not significant in different treatments. Maximum irrigation and rainfeed productivity and water use efficiency for the total dry matter were not significantly different between treatments. This oilseed has the potential to planting with a minimum of water consumption in the climatic conditions of the farm to an acceptable level. In general, based on the irrigation and rainfall water productivity index for the grain crop, if there is enough water available to the farmer, it is recommended to do full irrigation. Otherwise, dryland conditions are more suitable. Keywords Camelina, Deficit irrigation, Planting date, Seed yield, Water productivity

Germination plays a vital role in crop establishment and its yield. Most oilseeds are sensitive to salinity at germination, so cannot be irrigated with saline water. Although camelina is considered as a tolerant crop to water stress, but its tolerance to salinity must be investigated. To quantitatively evaluate camelina response to salinity at germination stage, an experiment with a completely randomized design was conducted including 17 water salinity levels of 0.85, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32 dS m-1, each with three replicates. Germination indicators were calculated using the SeedCalc package in R software and MATLAB. The optimization procedure was carried out with frequent changes in the model parameters based on reduced RMSE and minimizing least squares error. Then, parameters of salinity models including Maas-Hoffman, van Genuchten-Hoffman, Dirksen-Augustijn and Homaee et al. were derived and compared. The obtained threshold values of germination rate (GSI), seed vigor (SV), SeedCalc seed vigor (SV-S) were 2, 12 and 12 dS m-1, respectively; The corresponding reduction slope for these variables were 2.4, 7.7 and 1.7%, respectively. Based on the obtained EC* and the slope, it was concluded that camelina is very tolerant to salinity at this growth stage. So that, it can be established quickly and produce strong seedlings at very high salinity levels. Further analyses of model performance statistics indicated that the examined nonlinear models provide better performance. Best performance of fitted models was obtained by HVG and H models, respectively. Germination indices were decreased by increasing the salinity levels, a lower GSI was associated with decreased seeds water uptake. The higher the seed vigor, the higher the GSI and seedling growth, as well as the lower MGT. Overall, camelina can be considered as a suitable alternative for oilseed cultivation in semi-arid regions.