Molecular markers & plant breeding
Faramarz Hoshyardel; Reza Darvishzadeh; Hamid Hatami Maleki; Marjan Jannatdoust
Abstract
Chloride is considered as the most important micronutrient in tobacco production. But excessive amounts of chloride accumulation in leaves of tobacco have many adverse effects on the tobacco quality, such as burning capacity. Identification of quantitative trait loci (QTL) involved in chloride accumulation ...
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Chloride is considered as the most important micronutrient in tobacco production. But excessive amounts of chloride accumulation in leaves of tobacco have many adverse effects on the tobacco quality, such as burning capacity. Identification of quantitative trait loci (QTL) involved in chloride accumulation would be beneficial for the improvement of tobacco quality. The objective of this study was to identify genomic regions associated with chloride accumulation by using a mapping population consists of 225 F2:3 families derived from hybridization between ‘Basma Seres 31’ and ‘SPT 406’ lines. Linkage map was constructed with 23 microsatellite (SSR) and 29 inter simple sequence repeat (ISSR) polymorphic markers which covered 570.8 cM of the tobacco genome. Thirty-four of these polymorphic markers were mapped to 7 linkage groups. Distance between two adjacent markers was 17.3 cM. Composite interval mapping (CIM) was used to identify QTLs controlling chloride accumulation. One QTL for chloride accumulation was identified on linkage group 3. The percentage of phenotypic variance (R2) explained by this QTL was 12.7%. A significant association was not found between ISSR markers and chloride accumulation. The outcome of present effort can be a basis for marker aided selection (MAS) in tobacco breeding programs.
Plant breeding for abiotic & biotic stresses
Fariba Morsali Aghajari; Reza Darvishzadeh; Mitra Razi
Abstract
Salinity is one of the most important non-biological stresses that affect plant growth and development. Effect of different levels of NaCl (0, 2, 4, 6 and 8 dS/m) were investigated on enzymatic and non-enzymatic activities in C64 and C68 oilseed sunflower genotypes at two times; 3 and 12 days after salinity ...
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Salinity is one of the most important non-biological stresses that affect plant growth and development. Effect of different levels of NaCl (0, 2, 4, 6 and 8 dS/m) were investigated on enzymatic and non-enzymatic activities in C64 and C68 oilseed sunflower genotypes at two times; 3 and 12 days after salinity stress application. Net photosynthesis rate, chlorophyll content and soluble proteins amount decreased by increasing salinity level but proline and malondialdehyde (MDA) contents increased. However, the changes in net photosynthesis in the two studied genotypes was different across time and do not follow statistically the same trend line. In genotype C86, the reduction of photosynthesis rate at all studied salinity levels was very high compared to normal condition (0 dS/m) after 3 days; especially at salinity levels of 2, 4 and 6 dS/m, while 12 days later, the decrease of photosynthesis rate was moderate at salinity levels of 2 and 4 dS/m but severe at 6 and 8 dS/m salinity levels. The highest amount of proline (31.36%) related to tolerant genotype and the lowest amount (7.72%) related to susceptible one was measured 12 days after 2 dS/m salt stress treatment. Considerable MDA was observed in both tolerant and sensitive genotypes 12 days post salt stress application; the highest amount (83%) was observed at 8 dS/m treatment. Catalase and ascorbate peroxidase activity increased with increasing salt intensity. The rate of increase in guaiacol peroxidase activity was higher in C86 genotype than C64. Chlorophyll a and total chlorophyll contents decreased in both sunflower genotypes under salinity stress. The lowest amount of total chlorophyll (8.6%) was observed in the salinity level of 8 dS/m in the sensitive line (C64). Results revealed the C64 and C68 selected genotypes from two our identified sunflower heterotic groups have different physiological response to salinity stress and C68 is more tolerant to salt stress than C64. So, they can be potentially used as parents in sunflower breeding programs to produce salt stress tolerant hybrids.
Germplasm genetic diversity & plant breeding
Farnaz Goodarzi; Reza Darvishzadeh; Abbas Hassani
Abstract
Castor (Ricinus communis L.) is one of the most ancient medicinal oil crops in the world. It has been vastly distributed in different parts of Iran. In the present study, the inter simple sequence repeat (ISSR) markers were used to evaluate the molecular genetic diversity among and within 12 castor accessions ...
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Castor (Ricinus communis L.) is one of the most ancient medicinal oil crops in the world. It has been vastly distributed in different parts of Iran. In the present study, the inter simple sequence repeat (ISSR) markers were used to evaluate the molecular genetic diversity among and within 12 castor accessions collected from 7 regions of Iran. Totally, 16 ISSR primers amplified 166 loci, of which 116 loci (69.89 %) were polymorph, indicating high genetic variability in castor germplasm. An accession-specific ISSR band was detected in ‘80-29’accession. Genetic distance among accessions ranged from 0.2 to 0.056. Analysis of molecular variance revealed a higher level of genetic variation within (80%) than between (20%) accessions. A model-based Bayesian approach subdivided 60 genotypes from 12 accessions into 6 subgroups. UPGMA dendrogram based on Nei’s genetic distance classified 12 accessions into 4 groups. The result indicates that there was no association between geographical origin and ISSR patterns. The results suggest that ISSR technique is a useful tool for studying genetic diversity in castor germplasm.
Molecular markers & plant breeding
Nader Eyvaznejad; Reza Darvishzadeh
Abstract
Many agriculturally important traits are complex, affected by many genes and the environment. Quantitative trait loci (QTL) mapping is a key tool for studying the genetic structure of complex traits in plants. In the present study QTLs associated with yield and agronomical traits such as leaf number, ...
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Many agriculturally important traits are complex, affected by many genes and the environment. Quantitative trait loci (QTL) mapping is a key tool for studying the genetic structure of complex traits in plants. In the present study QTLs associated with yield and agronomical traits such as leaf number, leaf length, leaf width, plant height, stem and head diameter were identified by using 70 recombinant inbred lines (RILs) from the cross (♀) PAC2 × RHA266(♂). RILs and their parents were evaluated in a rectangular 8´9 lattice design with two replications. High genetic variability and transgressive segregation were observed in all studied traits. Genetic gain representing the difference between 10% of selected RILs and their parents was significant for most of the studied traits. Positive and significant genotypic and phenotypic correlations were observed among the studied traits. QTL analysis was performed using a recently developed SSR and SNP sunflower linkage map. The map consists of 210 SSRs and 11 SNP markers placed in 17 linkage groups (LGs). The total map length is 1,653.1 cM with a mean density of 1 marker per 7.44 cM. Composite interval mapping (CIM) procedure detected 21 QTLs involved in genetic control of studied traits. The phenotypic variance explained by the identified QTLs varied from 1.13 to 73.70%. QTLs such as HMBPP associated with the expression of more than one trait could increase the efficiency of marker-assisted selection (MAS) and genetic progress in sunflower.