Research Paper
Germplasm genetic diversity & plant breeding
Shahrbanoo Abbasi; amin Baghizadeh; Ghasem Mohammadi-nejad
Abstract
In order to study the genetic conditions of some agronomic traits in wheat, a cross was made between Gaspard and Kharchia varieties. F2, F3 and F4 progenies with parents were evaluated under drought conditions. Three-parameter model [m d h] considered as the best fit for number of fertile tiller and ...
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In order to study the genetic conditions of some agronomic traits in wheat, a cross was made between Gaspard and Kharchia varieties. F2, F3 and F4 progenies with parents were evaluated under drought conditions. Three-parameter model [m d h] considered as the best fit for number of fertile tiller and flag leaf length using generations mean analysis method. For number of grain per spike and main spike grain weight three-parameter model [m d i] was used. For number of spikelet per spike, grain yield and plant height four-parameter model [m d h i] was used. The heritability values ranged from 56% for flag leaf length to 81% for grain yield. The F3 generation with 100 individuals was used to construct a genetic linkage map. Using the method of composite interval mapping 3, 1, 5, 2, 2 and 1 QTLs were detected for plant height, grain yield, number of spikelet per spike, flag leaf length, main spike grain weight and number of fertile tiller respectively.
Research Paper
Plant breeding for abiotic & biotic stresses
Ehsan Mohsenifard; Mehdi Ghabooli; Nastaran Mehri; Behnam Bakhshi
Abstract
Drought stress is one of the most determinative factors of agriculture and plays a major role in limiting crop productivity. This limitation is going to rising through climate changes. However, plants have their own defense systems to moderate the adverse effects of climatic conditions. MicroRNA-mediated ...
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Drought stress is one of the most determinative factors of agriculture and plays a major role in limiting crop productivity. This limitation is going to rising through climate changes. However, plants have their own defense systems to moderate the adverse effects of climatic conditions. MicroRNA-mediated post-transcriptional gene regulation is one of these defense mechanisms. The root endophytic fungus Piriformospora indica enhances plant tolerance to environmental stress based on general and non-specific plant species mechanisms. In this work, we investigated the effects of drought and P. indica inoculation on the expression of two important miRNAs, miR159 and miR396, in rice plants. To this end, leaf samples were harvested at control (F.C.) and severe drought stress (25% F.C.) in P. indica-colonized and non-inoculated rice plants 4 weeks after fungal inoculation. We have observed contrary expression patterns of miR396 (down-regulated) and miR159 (up-regulated) under drought stress condition. However, both miRNAs showed up-regulation by P. indica inoculation. We have observed significant up-regulation of miR396 and miR159 by treatment of P. indica under drought stress condition. Regulation of growth, hyposensitivity response and bio-water saving pathways directly affected by MYB and GRF transcriptional factor. So, remarkable change of miR156 and miR396 could lead plant to be tolerable under drought stress by the fine regulation of MYB and GRF, respectively.
Research Paper
Plant breeding for abiotic & biotic stresses
Hamid Reza Ghorbani; Habibollah Samizadeh Lahiji; Ghorban-Ali Nematzadeh
Abstract
Salinity is one of the most important abiotic stresses that decrease crop production. Transcription factors (TFs) are prominent regulators in plant responses to abiotic stress. In the present study, the expression pattern of four salt-induced genes encoding transcription factors, namely, MYB, RF2, GTF, ...
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Salinity is one of the most important abiotic stresses that decrease crop production. Transcription factors (TFs) are prominent regulators in plant responses to abiotic stress. In the present study, the expression pattern of four salt-induced genes encoding transcription factors, namely, MYB, RF2, GTF, and ARID was studied in response to salt stress (sodium chloride) and recovery conditions. The results of quantitative real-time PCR (qPCR) showed that expression of genes was influenced by salt stress in A. littoralis. The expression level of all genes increased after 6 hours treatment by salt and after that, it drastically decreased with promoting of stress duration in both roots and shoots tissues but in a different manner. The expression of MYB gene in root (68.44) was the higher than shoot (38.57) after 6 hours of salt treatment, while the expression of other studied genes in the shoot was higher than root. At the recovery stage, the up-regulated expression of genes in different tissues gradually decreased and finally gets a stable value. The result showed that the studied transcription factors play an important role in tolerance of A. littoralis to salinity and could be used as an informative resource in the future breeding programs aimed to develop salt tolerant plants. Also, the response of A. littoralis to salt stress depends on the tissue type and duration of plant exposure to salt.
Research Paper
Molecular markers & plant breeding
Mohsen Mahmoodnia Meimand; Fatemeh Farzad Amirebrahimi; Hamid Reza Karimi; Khalil Malekzadeh; Ali Tajabadipour
Abstract
Genetic study of pistachio, especially male genotypes due to the effects of pollen on nut quality and quantity and next generation characterizations, help to improve its management and breeding programs. We studied the genetic diversity among 20 male and 36 female pistachio genotypes using ISSR marker. ...
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Genetic study of pistachio, especially male genotypes due to the effects of pollen on nut quality and quantity and next generation characterizations, help to improve its management and breeding programs. We studied the genetic diversity among 20 male and 36 female pistachio genotypes using ISSR marker. In total 178 DNA frgments were proliferated using 12 primers that 169 fragments were polymorphism. The average polymorphism information content (PIC) for the used primers were variable from 16 to up to 35%. Pistachio genotypes classified as five main categories by using cluster analysis. The most genetic similarity was between the ‘Poostkhormayee’and ‘Momtaz’ cultivars with 78% similarity and the lowest genetic similarity was between ‘Ravar3’ cultivar with ‘Ghazvini’cultivar and K40 genotype with 25% similarity. K38 male genotype had the lowest genetic similarity with female cultivars. Thus, it can be introduced as appropriate pollinizer for other studied cultivars. The results of analysis of molecular variance analysis showed that variability between male and female populations (8%) was lower than the variation within the populations (92%). Based on present results, ISSR marker was as a powerful tool to study the genetic variation among male and female pistachio genotypes.
Research Paper
Plant breeding for abiotic & biotic stresses
Behrouz Barzegargolchini; Ali Movafeghi; Ali Dehestani; Pooyan Mehrabanjoubani
Abstract
Salinity is one of the most important agricultural issues causing considerable yield reduction in agricultural crops. The main adverse effects of salinity are due to excess amount of sodium ions that is toxic to plant cells. Most halophytes are equipped with defense mechanisms enabling them to tolerate ...
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Salinity is one of the most important agricultural issues causing considerable yield reduction in agricultural crops. The main adverse effects of salinity are due to excess amount of sodium ions that is toxic to plant cells. Most halophytes are equipped with defense mechanisms enabling them to tolerate the salty habitats. Among grass plants, Aeluropus littoralis is a known monocots halophyte that can tolerate harsh saline conditions. In this study, salt treatment was applied in three levels of 0, 200 and 400 mM NaCl after 45 days and biological samples were collected at 7, 14 and 21 days after treatment (DAT). For microscopic analysis, the tissues were cross-sectioned and stained using methylene blue for lignified tissues and Congo red for cellulosic tissues. The amounts of Na+ and K+ were measured by flame photometer and the content of lignin was measured by polymeric thioglycolic acid derivatives method. The results showed that the amount of Na+ increased 13-fold, while the stem length, stem diameter, vascular bundle number, metaxylem diameter, phloem diameter, K+, fresh weight and dry weight decreased significantly by 35%, 48%, 59%, 19%, 25%, 45%, 64% and 55% under salt treatment, respectively. The amount of lignin in stem did not significantly change under salinity. According to these results, A. littoralis can tolerate saline habitats by different adaptation strategies like the limitation of minerals transition and reduction of plant biomass. Furthermore, the concentration of lignin in metaxylem tissues and stele parenchyma led to increased resistance of halophytes in excess amounts of Na+.
Research Paper
Molecular markers & plant breeding
Farideh Nik khoy; Mohammadreza Shiri
Abstract
Comparing different methods of estimating the genetic diversity could define their usefulness in plant breeding programs. In this study, a total of 18 morphological traits and 20 simple sequence repeat (SSR) loci were used to study the morphological and genetic diversity among 20 maize hybrids selected ...
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Comparing different methods of estimating the genetic diversity could define their usefulness in plant breeding programs. In this study, a total of 18 morphological traits and 20 simple sequence repeat (SSR) loci were used to study the morphological and genetic diversity among 20 maize hybrids selected from different countries, and to classify the hybrids into groups based on molecular profiles and morphological traits. To collect morphological data, a field experiment was carried out using an RBCD design with three replications in Moghan, Ardabil, Iran. The highest estimates for genetic coefficients of variation were observed in anthesis-silking interval, followed by grain yields, leaf chlorophyll rates, kernel row numbers, and ear heights. The total number of PCR-amplified products was 84 bands, all of which were polymorphic. Among the studied primers,NC009,BNLG1108,BNLG1194,PHI026 and PHI057 showed the maximum polymorphism information content(PIC) and the greatest diversity. To determine the genetic relationship among maize hybrids, the cluster analysis was performed based on both morphological traits(using the Ward method) and SSR markers (using the CLINK method). The cluster analysis of morphological traits divided the maize hybrids into five groups. Furthermore, Maize hybrids were divided into seven main groups based on SSR markers. Principal coordinate analysis (PCoA) of a similarity matrix of hybrids for SSR data showed that the first 15 coordinates explained 97.21% of the total variance, whereas the first two coordinates explained only 33.14% of the total variance. Generally, results indicated that SSR markers were able to classify closely related maize hybrids more efficiently than morphological traits.