جستجوی مقالات مرتبط با کلیدواژه « آب دریا » در نشریات گروه « زراعت »

Quinoa, Chenopodiom quinoa Willd., is an annual plant native to South America and the Andes mountains. It is a plant from the spinach and sugar beet family and despite its high nutritional value it can be cultivated well and produces a suitable crop in conditions where lands have low or limited fertility. Due to the high tolerance of quinoa to salinity stress, this plant was selected for cultivation with unconventional water sources. Given the lack of conventional water in Iran, especially in the southern regions, the use of unconventional water and the identification of tolerant plants with the ability to grow in saline conditions are important. Accordingly, due to the limitation of non-saline water, the use of sea water in coastal areas and low-yield lands can lead to agricultural prosperity in these areas.

This investigation was conducted with the aim of evaluating the effect of different concentration of the diluted sea water on germination traits and some morphological parameters of three quinoa cultivars including Red-Carina, Q26, and Q29 as factorial arrangement in completely randomized design with six replications. The used different concentrations of salinity in this study were 1.5 (control), 3, 6, 9, 12, and 15 dsm-1. To evaluate the germination traits, seeds were sown in petri dishes and then 10 ml of different salinity levels were added and petri dishes were placed at 25 °C for one week and the number of germinated seeds was recorded daily. The radicle exit was the criterion for germination. At the end of the period, germination percentage, germination rate, mean daily germination, peak value, and germination value were recorded. To investigate the effect of salinity on the morphological characteristics of quinoa, seeds were sown in the pots containing field soil at a depth of 1.5 to 2 cm. After sowing the seeds in the pots, irrigation with tap water was done until the germination stage according to the plant's water requirement. After ensuring the establishment of the plants (in the 4-leaf stage), salinity treatments were applied. Then the different traits such as the plant height, the number of lateral branches, the number of leaves, the length and width and area of the leaves, the length of inflorescence and seed weight were measured. The obtained data were analyzed using SAS 9.1 software and the means were compared using PLSD at p<0.01.

Based on the results of analysis of variance, there was a significant difference between the studied cultivars (p<0.01) in terms of germination percentage, germination rate, mean daily germination, and germination value, but salinity had no significant effect on germination percentage. The results also showed that no significant interaction between salinity and cultivar was observed in the percentage and germination rate as well as the peak value. The results of analysis of variance showed that the effects of salinity and cultivar on different morphological properties measured at p<0.01 were statistically significant, but the interaction of cultivar and salinity was significant only on the leaf length, width and area. The results showed that with increasing salinity from 9 to 12 and 15 dsm-1, a non-significant decrease was observed in germination rate compared to the control. With increasing salinity up to 15 dsm-1, the plant height, number of lateral branches, number of leaves, leaf length, and leaf area decreased and the highest yield was related to Q26 cultivar. Compared to the other two cultivars, the Q26 cultivar showed less sensitivity to salinity conditions in different traits such as leaf size and number, number of lateral branches, height before and after flowering.

In general, it can be said that salinity did not have an adverse effect on the germination rate of quinoa seeds and in some cases accelerated germination. However, at high salinity level, it affected some vegetative traits such as leaf and branch characteristics and inflorescence length. It seems that by performing a proper management in the field, the establishment and growth of this plant at levels of salinity can be guaranteed.

In regions with severe limitation of fresh water, salinity poses a serious threat to agriculture production due to its toxicity to most plants. Salinity tolerant plants that can survive and grow in high-salinity conditions are called halophytes. Halophyte cultivation has the potential to restore saline environments, provide for global food demands, produce medicine and biofuels, and conserve fresh water. Two approaches are presented to developing tolerant plants of seawater salinity; the first is increasing tolerance of conventional plants, and the second is choice from the large pool of halophytes, which already have the requisite salt tolerance. The difference between the upper limit of salt tolerance of conventional plants and required tolerance level to seawater salinity is huge. It has been shown that Salicornia spp. has the potential to tolerate salinity of seawater. Salicornia is a genus of succulent, halophyte flowering plants in the family Amaranthaceae that grow in salt marshes, on beaches, and among mangroves. Pickleweed (Salicornia bigelovii Torr.) is an obligate halophyte that has been considered as a promising plant due to the tolerance to hypersaline water and economic values such as forage production, oilseed production and fresh consumption. This study evaluated the response of Salicornia bigelovii to different water salinity treatments, determines its salt tolerance threshold and shows trend of the accumulation of Ca2+, Cl-, Na+ and K+ ions in the plant shoots.

This experiment was conducted as a completely randomized design with 4 replicates in the greenhouse of the National Salinity Research Center, Yazd, Iran. Saline water treatments included 2, 5, 8, 11, 14 and 17 dS m-1, which were prepared using dilution of Persian Gulf water. Salinity treatments were applied as irrigation of pickleweed (Salicornia bigelovii) plants with related saline water treatments. The 10 uniform seeds were sown in pots and were kept in a controlled environment with 26/18 °C (±3) day/night temperature regimes. The 84 days plants were harvested and were immediately transferred to the laboratory. Fresh and dry weight, dry matter, ash content and concentration of calcium (Ca2+), chloride (Cl-), sodium (Na+) and potassium (K+) were measured in shoots. Data were subjected to analysis of variance, and the means were compared using LSD at 5% probability level. Response cure was used to determine the threshold level of reduction after reaching the peak.

The results showed that salinity treatment was significant on all traits, except dry matter percent and potassium concentration. The results showed that increasing salinity up to 8 dS m-1 increased fresh and dry weight, however higher salinity levels were associated with reduction. The threshold level of reduction after reaching to the peak were 8.65 and 7.01 dS m-1 for fresh and dry weight, respectively. The amounts of reduction in fresh weight in 2, 5, 11, 14 and 17 dS m-1 treatments compared to 8 dS m-1 treatment were 26.9%, 9.5%, 12.0%, 20.0% and 35.8%, respectively. These reductions were 23.4%, 20.7%, 27.4%, 38.9% and 41.7%, respectively in dry weight. With increasing salinity of water, the ash content of shoots had an ascending and significant trend. The lowest and the highest shoot ash were related to 2 and 17 dS m-1 water salinity, by 24.8% and 41.3%, respectively. As salinity was increased, the concentration of chlorine and sodium in shoots were enhanced, while the concentration of calcium and potassium were reduced. Correlation and stepwise regression analyses revealed that concentration of calcium and potassium were the most important traits in salinity tolerance of salicornia. It seems that salinity tolerance in salicornia occurs by osmotic regulation as the accumulation of salts in its tissue.

According to the results of this study, it can be concluded that the capability of ions accumulation strengthens the phytoremediation ability of salicornia, however increasing in ash content could have a negative effect on the forage value of the plant. Therefore, determining the nutritional value of salicornia and feed analyzing in the presence of livestock require further evaluation.

Based on definition in this study, “halophytes are the plants adapted to saline conditions via one of the mechanisms of prevent salt entry to plant or reduced salt concentration in cytoplasm”. Therefore, the halophytes can be divided in two major classes: eu-halophytes and facultative halophytes. Literature review of the country revealed that considerable researches in halophytes has begun from the last half century and were remarkably increased from 2001 right now. The plants such as kochia (Kochia scoparia), purslane (Portulaca oleracea) and lambsquarter (Chenopodium album) have been well evaluated in terms of different growing aspects and it seems that some other plants such as quinoa (Chenopodium quinoa), salicornia (Salicornia spp.) and harmal seeds (Peganum harmala) have greater potential for attracting the researches. About 30%, 11%, 11%, 11%, 9%, 7% and 28% of these researches were conducted on growth aspects, physiological and biochemical traits, forage quality, implementation of strategies to improve production, plant nutrient and fertilization, oil status and others, respectively. The experiments in controlled conditions were more than twice as field experiments. In general, regard to more investigation on forage and oil quality of halophytes, the aspects of medical, sanitary and ornamental of halophytes should be evaluated in sustainable agriculture systems.