مجله چغندر قند
سال سی و چهارم شماره 2 (پاییز و زمستان 1397)

In order to evaluate the physiological and biochemical aspects of water deficit stress on six sugar beet genotypes, a factorial experiment based on completely randomized design with eight replications was carried out under greenhouse condition at Sugar Beet Seed Institute, Karaj, Iran, in 2015. Irrigation included two levels (normal irrigation and water deficit stress). Irrigation was equally applied to the both levels from sowing up to plant establishment after which irrigation in the water stress condition was done on the basis of stress symptoms appearance. Results showed that water deficit stress significantly decreased relative water content, root dry weight and water use efficiency and increased specific leaf weight, electrolyte leakage, leaf chlorophyll content, proline and betaine content. Chlorophyll and proline contents, root dry weight and root dry weight and water use efficiency were significantly influenced by genotype. The genotype by water treatment interaction was significant only for proline content and root dry weight. Electrolyte leakage, as a measure of cell membrane stability, was increased from 5242.58 µs.m-1 in normal condition to 941.21 µs.m-1 in water stress condition. The leaf chlorophyll content was increased in water stress condition. The highest and lowest chlorophyll content was observed in genotypes 1 (drought tolerant check) and 5 (PB13-S2-52.HSF-977), respectively. The highest proline content in water stress condition was observed in genotype 6 (PB13-S2-52.HSF-987), whereas the lowest value was observed in genotypes 3 (PB13-S2-37.153.80.HSF–1007) and 1. It seems that root dry weight, water use efficiency, and chlorophyll and betaine contents could be considered to initially screen the sugar beet genotypes for tolerance to water deficit stress.

Transition from vegetative to reproductive stage is one of the important procedures in most crops such as sugar beet which is regulated by the complex network of proteins. So far, several regulatory pathways involved in flowering and bolting and related genes have been identified in the Arabidopsis as a model plant. Age-related pathway is one of the important pathways involved in transition from vegetative to reproductive stage that is influenced by miR156 and miR172. In order to identify the sequence of the above mentioned genes in sugar beet genome, their sequences were collected from several plants and were aligned with sugar beet Refseq-genomic sequence. Regions with a common sequence were identified and evaluated in detail. For miR156 coding gene, only 127 bp in chromosome 2, and for miR172 coding gene only 110 bp in chromosome 9 had the full-length of miR precursor sequence in the sugar beet genome. In order to isolate the miR156 coding gene from the sugar beet genome, specific primers were designed. The miR156 coding gene was amplified from genomic DNA of sugar beet by polymerase chain reaction technique using specific primers of MIRF and MIRR. As expected, the 127 bp gene was amplified and showed 99% similarity with the sequence of the miR156. Identifying and studying these effective genes in the flowering process will open the way for the ability to verify their exact performance in sugar beet flowering and bolting processes.

The main objective of this study was to determine the potential areas for autumn sugar beet planting in North- and South Khorasan as well as Khorasan-e Razavi provinces with respect to some of its effective variables. For this purpose, meteorological data was collected from the Meteorological Office of the provinces for the stations of the region during 2005-2015, and then, using ArcGIS software, descriptive information was added to the maps. According to the required climate of sugar beet crop based on a hierarchial decision making model, parameter weight  and importance of each layer were determined by EXPERT CHOICE software. Among the criteria for decision making, bolting was the most important factor. Finally, using gravity overlapping operation in GIS, zoning of suitable areas for autumn sugar beet planting was carried out. According to the final map of the zoning, 9.71% of these provinces were classified as first class. Following the zoning to evaluate the feasibility of autumn sugar beet planting in Mashhad as a test model, an experiment was conducted in a split-plot based on randomized complete block design with three replications in 2015. This study showed a significant effect of planting date and cultivar on bolting percentage. Due to the results of this study and the final zoning map evaluation, it was shown that this area belongs to the second degree zones, so it seems possible to plant autumn sugar beet using resistant cultivars and selecting suitable lanting date in susceptible (first degree) regions of the studied provinces.

Predicting the performance of the crops to estimate production and determine the amount of agricultural inputs needed is crucial in precision agriculture. In the present study, a fast, accurate, and inexpensive method for estimating sugar beet yield with and without leaves was presented. Images were captured from the crop in both conditions and then, six morphological features including area, perimeter, major axis length, minor axis length, equivalent diameter and centroid were extracted from the images. Pearson correlation coefficient analysis was used to select the best effective feature. Features with a correlation coefficient greater than 0.7 were considered as effective features. Accordingly, for the two conditions of with and without leaves, area and perimeter characteristics were selected, respectively. To check the accuracy of the linear weight estimation equations, equations were given to the online crop recognition system (in two modes) and the root weight of the sugar beet was estimated immediately by tractor movement. Results showed that there was a correlation coefficient of 0.84 and 0.95 between the actual- and estimated weight in both with and without leaves conditions, respectively. According to the results, image processing system can be used as an estimation system for online sugar beet yield prediction.

The effect of foliar application of titanium (Ti) nanoparticles on biochemical, technological, and yield traits of sugar beet was studied in a split-plot experiment based on a randomized complete block design with four replications at Motahari Research Station, Kamalabad, Karaj, Iran in 2014. Main plot was assigned to foliar application stage (including 12-14, 25-30, and 30-35 leaf stage) and the sub-plots to solution dosage (including four levels of distilled water (control) and foliar application of TiO2 at 100, 300, and 500 mg/L levels). Results showed that TiO2 rate influenced sugar content and white sugar content significantly (p < 0.01) so that the highest sugar content (15.5%) and white sugar content (11.3%) were obtained from 100 and 300 mg/L TiO2 application, showing an improvement of 0.5 and 0.8 units versus control. This effect was independent of foliar application stage. On the other hand, the effect of TiO2 application on root impurities caused a significant increase of 2.5 units in the extraction coefficient of sugar treated with 100 mg/L TiO2. The increase in the rate of TiO2 nanoparticles increased enzyme catalase, leaf soluble protein, and carotenoids and also decreased peroxidase and chlorophyll a and b. Overall, the TiO2 nanoparticles application at 100 mg/L during the growing season can improve the quality of sugar beet corp.

Sugar beet (Beta vulgaris L. sub sp. vulgaris) is an industrial crop which is mainly grown for sugar extraction from its root, and is also used directly and indirectly by human and livestock. This study was carried out during October to December 2016 to determine the residues rate of two highly consumed insecticides called Chloropyrifos and Cypermethrin, on sugar beet produced in Urmia, Khoy, Salmas, Bukan, Miandoab, Mahabad and Naghedeh and pulps from three sugar factory of Urmia, Miandoab and Naghadeh in West Azerbaijan province. High Performance Liquid Chromatography (HPLC) was used for this purpose. Results of the samples from Urmia, Khoy, Salmas, Bukan, Miandoab, Mahabad and Naghedeh showed that the chlorpyrifos insecticide in the city of Khoy had the highest residual rate, and followed by samples from Miandoab, Bukan, and Salmas, respectively. In the root samples collected from Mahabad, Naghdeh, and Urmia, and pulp samples from Miandoab, Urmia and Naghdah factories no insecticide residues were detected. In the case of Cypermethrin, the highest residuals were in Khoy followed by Bukan, Naghadeh, Miandoab and Urmia, respectively.. No cypromethrin insecticide residues were found in Mahabad and Salmas areas and in pulp obtained from Miandoab, Urumia and Naghadeh.

All living organisms have mechanisms to deal with the harmful effects of ultraviolet (UV) radiation. In this study, the effects of three UV-B doses on some physiological properties of sugar beet cultivar, BR1 was evaluated in a completely randomized design with three replications. All plants were kept in a growth chamber at 25/20 ºC (day/night) with a 16 hours light and 8hours dark photoperiod for 30days. Then, plants were divided into 4 groups including control and three experimental groups exposed to 3.042, 6.084 and 9.126 KJm-2d-1UV-B radiation, respectively for one week. Results indicated that the highest amount of UV-B (9.126 KJm-2d-1) induced an 11% reduction in soluble sugar content of the leaf tissue. Treatment with 3.042, 6.084 and 9.126 KJm-2d-1UV-B resulted in 80, 82, and 86% increase in flavonoids content, respectively. Moreover, the highest amount of UV-B caused a 24% increase in total phenolic compounds content. Furthermore, UV-B radiation caused a significant increase in amounts of betalains (betanin and betaxanthin). The antioxidant activity of leaf methanolic extract increased under UV-B radiation. Evaluation of betaninand betaxanthin antioxidant activity also revealed that these pigments cause α, α-diphenyl-β-picrylhydrazyl free radical inhibition and betaxanthinhasa higher antioxidant activity than betanin. Increase in UV irradiation intensity increased the secondary metabolites and, consequently, increased the antioxidant capacity of the crop.

Sugar beet is one of strategic products in the crop rotation of Qazvin plain which is endanger of natural, human, and intentional hazards. In this regard, the product yield insurance plan, as an efficient economic strategy in risk management, can protect beet farmers against incurred damages. Given the importance of this issue, in this study, the rate of Qazvin plain farmers participation in sugar beet yield insurance plan under premium rate policy was analyzed. For this purpose, an econometric modeling system based on the multi-period positive mathematical programming (MP-PMP) model and exogenous price elasticity (EPE) approach was used. The required data were from time series (1999-2017) and cross-sectional (2016-2017) that were collected through documentary data and questionnaires from 138 farmers. Results showed that with participation of small, medium, and large beneficiary groups in the yield insurance plan, an increase in sugar beet planting area by 56.9, 61.6, and 71.3% and the gross profit of cropping pattern of 10.3, 12.1 and 14.4% were recorded, respectively compared with non-participation condition. In addition, with 50-70% reduction in government support of premium rate only large beneficiary sample were interested to participate in sugar beet yield insurance plan. Under these conditions, sample beneficiary of small and medium groups will be excluded from the plan and may be skeptical of sugar beet production which in inconsistent with the objectives set out in government programs.