جستجوی مقالات مرتبط با کلیدواژه « total soluble solid » در نشریات گروه « زیست شناسی »

Rana Valizadeh Kamran1, Lamia Vojodi Mehrabani2, Ali Aryan1 & Alireza Tarinejad11Corresponding author: Rana Valizadeh Kamran, [email protected]. Bioremediation is a promising strategy to reduce the concentration of heavy metals that their increase in the soil was the result of the development of industries and factories in the area, threatening the environment and human health. To investigate the effect of the heavy metal chromium and the reduction of its toxic effects by bacteria (at two levels of the absence of bacteria and the presence of bacteria in Hoagland's solution), a factorial experiment was conducted as a completely randomized design with three replications and the morphological, physiological traits and plant elements were measured in the applied treatments. The results showed that the experimental treatments did not affect plant yield traits, fresh weight, stem length, and leaf length. Leaf width, chlorophyll a, b, and plant phosphorus content decreased under chromium stress and increased with bacterial treatment. Hydrogen peroxide, malondialdehyde, ascorbate peroxidase, superoxide dismutase, catalase, proline, solid soluble substances, phenol, flavonoid, and anthocyanin, as well as the content of plant elements such as chromium, nitrogen, and potassium, increased due to the chromium treatment. Using bacteria in the culture medium containing chromium, significantly decreased the hydrogen peroxide and malondialdehyde, indicating a reduction in the oxidative stress. The non-enzymatic and enzymatic antioxidants of plats in the bacterial treatments increased, indicating bacteria's role in strengthening the plant's antioxidant system. The chromium content of the plant decreased after the use of bacteria. The results showed the positive effect of using chromium-purifying bacteria in the environment of plant cultivation in reducing the harmful effects of chromium heavy metal stress.

Citrus is one of the most important fruit crops known by human. They are mainly grown in humid and arid subtropical regions. Citrus fruit undergo physico-chemical changes such as shrinkage, weight loss, decay as well as decrease in vitamin C during storage, which directly affects on fruits quality. Pre-harvest foliar application of salicylic acid (SA) is an efficient and safe technique to maintain fruit quality during storage. This study was carried out to evaluate the pre-harvest spray of SA (0, 1, 3 and 5 mM) on improving the shelf life and fruit quality of mandarin (Citrus reticulata L. ‘Pearl Tangelo’). The fruits were stored for one month at common storage (12±2˚C) and refrigerator (4±1˚C) and factors included peel moisture (%), fruit peel, juice and pulp weight (%), pH, TSS, TA, TSS/TA and vitamin C evaluated every week. The results showed that salicylic acid played a major role in increasing of fruit storage life. The highest percentage of peel moisture in both temperature conditions was observed with 5 mM salicylic acid. Low concentration of SA significantly preserved vitamin C, as the highest amount of vitamin C (64 mg per 100 ml of juice) were belonged to 1 mM salicylic acid at both common and cold storages. The lowest TSS/TA (9.2) was obtained with untreated SA-fruits in the common storage. The peel moisture (%), vitamin C and TSS/TA decreased during storage. The pH of fruit juice increased slightly in the second to fourth week of storage compared to the first week. There is a negative correlation between fruit juice weight (%) with TSS and TSS/TA. Since salicylic acid treatments are easy to set up and inexpensive, pre-harvest foliar application of SA could be a useful strategy to maintain physico-chemical and sensory quality parameters of mandarin fruit and prolong the storability of fruits during storage.

In order to investigate the effect of plant growth regulator paclobutrazol and hydrogen peroxide on growth, yield and fruit quality of melon (cv. Khatooni), the experiment was set out in a randomized complete block design with three replications in the research farm of University of Zanjan. Treatments include pruning (control), thinning, three levels of hydrogen peroxide (2.5, 5 and 7.5 mM) and paclobutrazol at three levels (10, 20 and 30 mg.L˗1) in 4 -6 leaf and fruit set stages. The result showed that foliar application of hydrogen peroxide increased the total soluble solids content. Thinning treatment had no significant effect on growth and fruit quality but increased yield compared to the control plants. Foliar application of paclobutrazol reduced growth and increase yield fruit and total soluble solids content compared to the control plants. According to result, the highest fruit weight, fruit yield and total soluble solid and the lowest number of stem and plant length was obtained with application of paclobutrazol 10 mg.L˗1 at 4 to 6 leaf stage, so foliar application of paclobutrazol (10 mg.L˗1 at 4 to 6 leaf stage) can be proposed instead of plant thinning practice that require too much time and labor for the farmers. Also hydrogen peroxide 7.5 mM increased dramatically total soluble solids contents, sucrose and fructose that it is recommended to improve quality of melon fruit.