جستجوی مقالات مرتبط با کلیدواژه « biochemical » در نشریات گروه « زراعت »

Drought is one of the most important stresses that inhibit growth of plants and due to mainly disturbance of the balance between the production of reactive oxygen species and antioxidant defense, causes oxidative stress and different biochemical and physiological responses in plants. So, the evaluation of plants for drought tolerance to cultivate in dry regions is very important.In this way, the present study aimed to investigate and compare two native barley cultivars of Sistan region (Nimroz and Nomar) based on measurement of some defense mechanisms and physiological properties including Antioxidant enzymes activity (Catalase (CAT), Ascorbate Peroxidase (APX), Polyphenol oxidase (PPO)) photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids), protein content, relative leaf water content (RWC) and some Osmotic regulators (proline and carbohydrate) were under drought stress. This experiment was performed as a factorial in a completely randomized design with three replications, conducted at the Institute for Biotechnological Research in the University of Zabol. Experimental treatments included drought stress (50%, 75% and 100% of the field capacity (control)) and two cultivars native to Sistan region (Nimroz and Nomar). Analysis of variance showed that the effect of cultivar, drought stress and interaction of cultivar and drought stress were significant at 1% probability levels, on all studied traits. Results indicated that with increasing drought stress levels compared to normal levels, the amount of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids), protein content and relative leaf water content (RWC) decreased. However, proline and carbohydrate concentration, carotenoid content, the activity of antioxidant enzymes CAT, PPO and APX were increased. Based on the results of the interaction, it was identified that Nimroz cultivar had a better reaction than Nomar cultivar in terms of protein, relative leaf water content, carotenoids, osmotic regulators and antioxidant enzymes (catalase and ascorbate peroxidase) during drought stress. While the Nomar cultivar was the highest average in terms of chlorophyll a, chlorophyll b, total chlorophyll, protein and enzyme polyphenol oxidase compared to the Nimroz cultivar during drought stress.

Drought is the abiotic stress to decrease yield potential. To screen and identify drought tolerant genotypes of bread wheat landraces, was studied in a randomized complete block design with three replications with two levels of stress (stress and non-stress environments) and 25 bread wheat genotypes, at the Razi University of Kermanshah in 2017-2018. Results of analysis of variance and mean comparison of morphological, physiological and biochemical traits showed that effect of genotype was significant for most of the traits under stress. Correlation coefficients showed a positive and significant result between yield with thousand seed weight and biological yield in both stress and non-stress conditions. Analysis of variance and mean comparisons showed that genotype No. 10 was superior under both stress and non-stress conditions. The results of correlation between drought stress indices showed that STI, MRP and biological yield were positively and significantly correlated with grain yield under both stress and non-stress conditions. Ranking of genotypes, based on sum of ranks, mean ranks and standard deviation of ranks, showed that genotypes 10, 15 and 18 were best rank and recognized as superior drought resistant genotypes, while genotypes 4, 16, and 22 were identified susceptible. Factor analysis in stress environment explained 80.55% of the variance by four main factors. Ward's cluster analysis under stress condition divided the genotypes into four groups. Grouping of genotypes were somewhat different due to different responses of bread wheat genotypes to water deficit stress and their differences in susceptibilies or relative resistancese.

In order to investigate the effect of zinc and silicon spraying on some of the quantitative and qualitative traits of Lallemantia iberica (Urmia Landrace), a split plot experiment based on randomized complete block design with three replications was conducted at Research Farm of Urmia University in 2016-2017. The two rainfed and supplementary irrigation systems were considered as the main plots, and the spraying of zinc, silicon and untreated control as the sub-plots. The main effects of environment, spraying and their interaction were significant on the most of the studied traits. The highest amounts of chlorophyll, carotenoids, potassium and zinc were obtained from zinc application. The highest amount of soluble carbohydrates, phosphorus, and silicon was observed in silicon spraying. There were no significant differences, in term of leaf relative water content, between Zn or Si treatments in both stress conditions. The highest percentage of seed mucilage belonged to Si spraying of rainfed plants. The highest seed oil content were occurred at Zn spraying (23.7%), and however obtained from rainfed (23.9%) plants. The amounts of grain yield of Lallemantia iberica (Urmia Landrace) either in rainfed conditions or supplemental irrigation was for zinc application (613.3 and 688.3 kg ha-1, respectively) and silicon spraying (657.3 and 668.7 kg ha-1, respectively) more than untreated control plants

Citrus often were encountered with periodic droughts. For this reason, drought effect on six-month-old seedlings of Poncirus (PT) (Poncirus trifoliata Raf.),Troyer citrange (TC) (Citrus sinensis Osbec. × Poncirus trifoliata Raf.),Citrumello (CR) (Citrus paradisi M. × Citrus sinensis Osbec.),Sour orange (SO) (Citrus aurantium L.),andCleopatra mandarin (CM) (Citrus reshni L.) were tested on 2014 in Ramsar Citrus Research Institute. This research was conducted as factorial experiment based on completely randomized design with three replications. The factors included commercial Citrus rootstocks and two level of irrigation. The results showed that maximum quantities of proline, total soluble sugars, malondialdehyde and carotenoid and minimum quantities of total, b and a chlorophyll were observed in drought stress. Maximum accumulation of proline (ordered 306.41 and 281.65 µmol/gdw) and total soluble sugars (ordered 233.79 and 137.9 mg/gdw) and minimum accumulation of malondialdehyde (ordered 179.21 and 204.1 µmol/gdw) were observed in SO and CM rootstocks under drought stress. Decreasing amount of total and chlorophyll a in CM and chl b in SO rootstock was more than other rootstocks and decreasing amount of total and b, a chlorophyll in CR was least. Furthermore, increasing amount of carotenoid in SO and CM was most and the least amounts in PT was observed. On the basis of the study, trifoliate rootstocks as Poncirus, Troyer citrange and Citrumello tolerate as much as drought.

This study was done to evaluate the effects of harvest time on some factor of ‘Ahmadaqaie’ pistachio nuts in Rafsanjan. In three consecutive years (2009-2012) during three stages of friut ripening (40، 70 and 100 percent of hulling)، fruit was harvested and physiological and biochemical parameters were measured. The experiments were conducted as randomized complete block design with compound analysis in three replications. Most of the traits were influenced by harvest time more than latitude and length of piistachio. The highest amount of protein (20. 5%)، chlorophyll content (6 mg) and inflorecence bud retention (61%) was in immature nuts (40 percent). Pistachios harvested in stage two (70%) had the best quality and quantity despite of green kernal and good taste of immature pistachio nuts. Although third harvest (100%) increased the dry weight and percent of nut splitting، but have some problems including increasing early splitting، endocarp yellowing، nut drop under the trees، and finally difficult to harvest operations which will increase fungal infections and reduce the nutritional value. In the best time of harvesting in normal condition، the nutritional value، splitting and dry matter were high that roughly coincides with the 70 to 80 percent ripening stage.

The propose of this research was to evaluate the physical and biochemical characteristics of fruits in selected mango trees. Twenty six mango genotypes were studied in Minab, Hormozgan Province, Iran. A completely randomized design with 26 treatments and 4 replications was adopted. Each treatment was represented by one genotype. Several parameters related to fruit quantity and quality, such as width, length, weight of fruit and pit, pulp percentage, total soluble solids (TSS), titratable acidity (TA) and Vitamin C content, were evaluated. The results were submitted to variance analyses, the Duncan test and cluster analysis. Results showed that the mango genotypes studied in Minab presented statistical differences, in relation to fruit quantitative parameters. Also, mango genotypes presented high variation in TSS, TA, Vitamin C content and total sugars. In spite of fruit and pit weight and size, biochemical characteristics of fruit in genotypes were found to have potential for using in breeding programs.