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Showing 6 results for Najafi
Reza Mir Drikvand, Goodarz Najafian, Mohammad Reza Bihamta, Asa Ebrahimi,
Volume 1, Issue 2 (2-2015)
Abstract
This study was conducted to identify markers associated with some kernel traits in bread wheat in two separate experiments under field and laboratory. One hundred wheat genotypes were evaluated in an alpha lattice experimental design with two replications. Grain hardness, seed length, seed width and thousand kernel weights were measured. Association mapping was performed based on 96 unlinked and 22 SSR QTL linked markers, using structure and Tassel software. Correction for population structure was performed using genome wide SSR markers so that genotypes were divided into six sub-populations. Totally, 35 SSR markers linked to traits were detected eight of them being QTL linked markers and other markers that were linked to traits, were used to investigate population structure. The QTLs linked markers were as follows: Chromosomes 5B, 5D and 6D had three QTL for grain hardness. Nine QTLs were detected on chromosomes 1A, 1B, 2A, 2B, 2D, 5B, 5D, 6D and 7B for kernel length, kernel width and thousand kernel weights. The results of this study demonstrate that association mapping is a useful approach to complement and enhance previous QTL information for marker-assisted selection in wheat.
Reza Nikooseresh, Goodarz Najafian,
Volume 3, Issue 1 (9-2016)
Abstract
In order to study genetic diversity, heritability and relation of some important traits with grain yield in bread wheat, 20 bread wheat irrigated lines evaluated using a randomized complete block design with three replications during two cropping cycles/years. Based on combined analysis results, there were a significant difference between genotypes. Also, in all traits, coefficient of phenotypic variation was greater than coefficient of genetical variation, indicating the effect of environment on investigated traits. The significant correlation between grain yield and number of days to maturity, spikes per m2 and the grains per spike. number of days to heading and number of days to maturity had highest heritability among traits, with 87 and 69%, respectively. Results of this showed that selection of early heading or shorter no. of days to heading and early maturing or shorter number of days to maturity is recommended to breeders for selection materials favorable for terminal warm condition and water shortage, preventing grain yield reduction. Results of cluster analysis showed that genotypes are divided in six groups. Totally, six superior genotypes from the fourth cluster were selected as superior lines. Based on bi-plot analysis, genotypes 14 and 5 showed the lowest genotype × trait interaction, but genotypes 16 and 8 showed the highest genotype × trait interaction.
Mohammad Reza Salavati Meybodi, Gholam Ali Ranjbar, Seyed Kamal Kazemitabar, Hamid Najafi Zarrini,
Volume 4, Issue 1 (9-2017)
Abstract
Water stress is one of the most common environmental stresses that limited tobacco production in IRAN. Identification of genetic diversity in tobacco germplasm and genetic relationships between traits help to improve tolerant varieties. In this study, the genetic diversity of 100 flue–cured tobacco (Nicotiana tabacum L.) cultivars was analyzed using 15 morpho-physiological traits and 25 ISSR primers. The cultivars were cultured in a simple lattice design (10×10) with two replications (with and without water stress) in Tirtash Tobacco Institute, Iran. Results showed relative water content (RWC) and cell membrane stability (CMS) in normal condition were significantly higher than stress condition. The estimated broadsense heritability was low for RWC and CMS that represents large environmental effects on these two traits. The results of genotypes clustering by UPGMA method with ISSR markers and by WARD method with morph-physiological traits did not match. Primer UBC814: (CT) 8A with 16 polymorphic bands of the 17 bands, had higher resolution than other primers and seems appropriate for molecular diversity studies in tobacco. The K394 genotype was identified as well as drought tolerant varieties. We can use results of this study for selecting genotypes with great genetic differences and chose the desirable traits and use in breeding programs for producing high heterosis hybrid with tolerance to drought stress in tobacco.
Shaghayegh Mehravi, Gholam Ali Ranjbar, Hamid Najafi-Zarrini, Ghader Mirzaghaderi,
Volume 7, Issue 1 (9-2020)
Abstract
Anise is an annual plant belonging to Apiaceae family and fruit essential oil of this herb is used in various pharmaceutical, cosmetic and beverage industries. Drought stress is one of the most critical limiting factors for anise production in worldwide. In this research, to finding interrelationships among different traits and performance, some anise genotypes were evaluated using the biplot method. In this study, 18 anise genotypes were evaluated in normal irrigation regime and drought stress conditions according to a randomized complete block design with three replications at the field of the Western Australia University (UWA), Australia. Fifteen phonological, morphological and physiological traits were measured. Results indicated the positive and significant correlations between yield and fruit number and fruit thousand weight in both conditions. Due to the negative correlation between phonological features with fruit yield in two different irrigation conditions, it could be concluded that to have genotypes with high fruit yield, selection for early ripening genotypes should be done in anise. In this study, a significant correlation was observed between fruit yield and relative water content in the stress condition. Therefore, this trait can be used as a physiological index to evaluate drought tolerance in anise. According to cluster analysis based on the measured traits, genotypes were divided into 3 groups in both non-stress and stress conditions. According to the results of the comparison of the means of the groups in non-stress and drought stress conditions, genotypes No. 1, 5, 6, 11, 12, 14, 15 and 16 were identified as the most drought-tolerant genotypes. These genotypes could be utilized in breeding programs for further improvement of drought tolerance in anise germplasm.
Seyede Sharare Arianezhad, Hamid Hamid Najafi Zarini, Mehdi Ghaffari, Gholamali Ranjbar,
Volume 9, Issue 1 (9-2022)
Abstract
This research was carried out to estimate the genetic variance components for sunflower fatty acids in two separate optimum and drought stressed conditions in Karaj during 2020 and 2021 growing seasons. The plant materials consisted of 12 hybrids derived from crossing of four restorer lines by three cytoplasmic male sterile lines (Testers) that were evaluated in two separate experiments as randomized complete block design with three replications. Drought stress made a reduction in oil yield (34 percent), oil content (six percent), stearic acid (4.7 percent) and oleic acid (10.6 percent) and an increase in palmitic acid (12 percent) and linoleic acid (2.8 percent). Line × tester interaction effect had a major role in explanation of the variance of the hybrids in terms of fatty acid content in both conditions, indicating the critical role of non-additive effects in genetic control of these traits. Under optimum irrigation, oil yield, oil content and stearic acid content were under control of both additive and dominant gene action and palmitic, oleic and linoleic acids were under control of dominant gene action. Under drought stress, except oil content which was under control of additive effects, all the other traits were under control of dominant gene action. According to the results of this study, fatty acid composition of sunflower was under control of non-additive genetic effects and the crossing-based methods and hybrid breeding could be used for improvement of sunflower in terms of fatty acid composition.
Saeid Navabpour, Horeyeh Najafi,
Volume 9, Issue 2 (3-2023)
Abstract
Environmental stress is one of the main factors that reduce the growth and performance of crops and threatening human food security. This study was conducted in order to investigate the effect of drought stress on the changes in biochemical traits and the level of expression of a MYB transcription factor gene in two wheat cultivars (Tajan and Zagros), under drought stress. The experiment was conducted as a factorial based on a completely randomized design with 3 replications. Drought treatments were applied at three levels of 40, 70 and 100% of field capacity 4 weeks after germination. Twenty days after the application of stress, leaves and roots were sampled in order to investigate the expression of MYB genes and measuring some biochemical traits. The results of examining the chlorophyll content under stress showed that the content of chlorophyll a and b decreased with increasing of stress intensity in different genotypes. The rate of reduction of chlorophyll a and b in Tajan genotype under severe stress was higher than Zagros genotype. Also, TBARM content under severe drought stress was significantly higher than moderate stress condition and this increase was seen in Tajen genotype more than Zagros genotype. qRT-PCR analysis showed that the MYB genes showed an increase in expression under drought stress. Furthermore, Zagros genotype, which is considered as a tolerant cultivar to drought stress, had a higher MYB expression level than Tajan cultivar for both genes, suggesting this cultivar for future breeding programs, also considering the importance MYB family genes during drought stress, the results can be used in molecular breeding and pyramiding breeding projects.
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