Iranian Landraces Research Articles

Variability for Glutenins, Gluten Quality, Iron, Zinc and Phytic Acid in a Set of One Hundred and Fifty-Eight Common Wheat Landraces from Iran

Bread wheat can be used to make different products thanks to the presence of gluten, a protein network that confers unique visco-elastic properties to wheat doughs. Gluten is composed by gliadins and glutenins. The glutenins can be further divided into high and low-molecular-weight glutenins (HMWGs and LMWGs, respectively) and are encoded by Glu-1 and Glu-3 loci. The variability of these genes is associated with differences in quality. Because of this, the identification of novel glutenin alleles is still an important target. In this study, 57 haplotypes or glutenin combinations were registered among a set of 158 Iranian landraces and five novel HMWGs alleles were identified. The landraces were also characterized for several quality traits, including gluten quality, which allowed to associate the different glutenin alleles with low or high quality. Other quality traits examined were iron, zinc, and phytate contents, which are intimately related with the nutritional quality. Important variation for these components was found as well as for the phytate:iron/zinc molar ratios (related to the potential bioavailability of these important micronutrients). The landraces identified in the present study (some of them combining high gluten quality with low phytate:zinc values) could be a useful resource for breeders who aim to improve the wheat end-use quality and especially the content of zinc and its relative bioavailability.

The influence of breeding history, origin and growth type on population structure of barley as revealed by SSR markers

Natural and mass selection during domestication and cultivation favored particular traits of interest in barley. In the present study, population structure, and genetic relationships among 144 accessions of barley landraces and breeding materials from various countries were studied using a set of 77 and 72 EST-SSR and gSSR markers, respectively distributed on seven chromosomes of barley. In total, 262 and 429 alleles were amplified in 77 EST-SSRs and 72 gSSR loci, respectively. Out of which, 185 private/group-specific alleles were identified in the landraces compared with 14 in "cultivar and advanced breeding lines", indicating the possibility to introgress favorite alleles from landraces into breeding materials. Comparative analysis of genetic variation among breeding materials, Iranian landraces, and exotic landraces revealed higher genetic diversity in Iranian landraces compared with others. A total of 37, 15, and 14 private/group-specific alleles were identified in Iranian landraces, exotic landraces, and breeding materials, respectively. The most likely groups for 144 barley genotypes were three as inferred using model- and distance-based clustering as well as principal coordinate analysis which assigned the landraces and breeding materials into separate groups. The distribution of alleles was found to be correlated with population structure, domestication history and eco-geographical factors. The high allelic richness in the studied set of barley genotype provides insights into the available diversity and allows the construction of core groups based on maximizing allelic diversity for use in barley breeding programs.

Genome diversity and population structure analysis of Iranian landrace and improved barley (Hordeum vulgare L.) genotypes using arbitrary functional gene-based molecular markers

Barley (Hordeum vulgare L. subsp. vulgare) is one of the earliest domesticated crop plants, which originated in Fertile Crescent. Genetic diversity analysis in primary gene pool and landraces is an effective strategy for germplasm conservation and utilization in breeding programs. In this study, Eighty-two barley genotypes comprised 22 Iranian improved cultivars and 60 landrace accessions collected from different zones of Iran were assumed for genetic diversity analysis using three gene targeted markers, start codon targeted (SCoT) polymorphism, conserved DNA-derived polymorphism (CDDP) and CAAT box-derived polymorphism (CBDP) in comparison with sequence-related amplified polymorphism (SRAP) markers. A total of 40 primers (10 primers from each marker) detected genetic polymorphism among barley genotypes. Four different marker types showed high level of polymorphism and SRAP markers produced higher number of polymorphic bands (67) in comparisons with SCoT, CDDP and CBDP. Average PIC values for SCoT, CDDP, CBDP and SRAP were 0.33, 0.37, 0.37 and 0.31, respectively. Marker index (MI) in SRAP and CBDP markers was higher than SCoT and CDDP markers. Cluster analysis using CDDP, CBDP and SRAP markers grouped barley genotypes in three distinct groups, while SCoT markers divided genotypes in four clusters. There were positive correlations between similarity matrixes obtained by each marker types. The results from cluster analysis and STRUCTURE analysis using combined data grouped barley genotypes in three clusters and the grouping of genotypes was strongly in agreement with their origins. Results showed that genotypes from west and north-west of Iran grouped in distinct clusters from those originated from north-east and center of Iran. To our knowledge, this is the first detailed report of using gene targeted molecular marker for genetic diversity analysis in barley. Our results showed the efficiency of these markers for genetic diversity analysis in barley and their potential for genome diversity and germplasm conservation.

Leaf Area, Relative Water Content and Stay-green Habit of Iranian Landraces (Triticum aestivum L.) under Water Stress in Field Conditions

Water stress is one of the major and challenging abiotic stress that affects the plant mostly at all stages like tillering, booting, anthesis, grain formation and grain filling. The aim of the present study is to investigate the effect of water stress on relative water content, leaf area and stay green habit of Iranian landraces along with commercial relevant checks under irrigated, restricted irrigation and rain-fed conditions. Iranian landraces were selected based on minimum reduction in vigor index as compared to control lines during preliminary screening experiment in the lab in which water stress is induced by Polyethylene glycol (PEG 6000). A field experiment was carried out at the experimental area of the Department of Plant Breeding & Genetics, Punjab Agricultural University, Ludhiana, Punjab during 2016-2017. The relative water content of Iranian landraces was calculated at the bolting stage according to the turgid weight by applying the equation of relative water content. Leaf area was recorded by leaf area meter and stay-green habit based on a 1-4 visual scale. Analysis of variance revealed interaction among treatment and genotypes was significant (P≤ 0.05) for the leaf area, relative water content, stay green habit at anthesis and 30 days after anthesis. Leaf area, relative water content and stay green habit of Iranian landraces along with commercial checks reduced under water stress conditions. Based on the performance of Iranian landraces under stress conditions, 5 lines IWA 8600397, IWA 8600567, 8606739, IWA 8606786 and IWA 8600753 were considered as water stress tolerant.

Assessment of biochemical and physiological parameters of durum wheat genotypes at the seedling stage during polyethylene glycol-induced water stress

Wild and landrace progenitors of wheat are an important source of resistance to various types of environmental stress, which can be explored in wheat breeding. With the aim of providing genetic materials for breeding to generate drought-resistant varieties, 50 durum wheat landraces, breeding lines and local cultivars were evaluated at the seedling stage for biomass, physiological parameters (e.g. photosynthetic pigment and relative water contents) and activities of key enzymatic antioxidants [e.g. ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD)] under optimal and polyethylene glycol (PEG)-triggered water stress. We observed significant differences in the measured parameters among the durum wheat genotypes in response to PEG-induced water stress. Biomass and physiological traits showed a decreasing trend, whereas the antioxidant enzyme activities displayed an increasing trend in the investigated durum wheats under PEG-induced water stress. PEG-induced water stress decreased the average means of total soluble protein, chlorophyll a and total chlorophyll contents of the 50 investigated genotypes by 51.42, 36.77 and 26.15%, respectively, while the mean values of POD and SOD activities increased by 173.33 and 92.26%, respectively, relative to the control. A principal component analysis (PCA)-based biplot demonstrated that the stress tolerance index (STI) positively correlated with the root and shoot dry weights as well as CAT, SOD and APX activities. In conclusion, several breeding lines (e.g. G10, G19 and G20), Iranian landraces (e.g. G42 and G47) and local cultivar (G49) showed a better adaptive response to PEG-induced water stress than other tested genotypes, suggesting that these genotypes could be explored in various breeding programs to create new wheat cultivars with beneficial water stress-adaptive traits.

Identification of wheat germplasm resistant to major Russian wheat aphid biotypes in the United States

AbstractRussian wheat aphid (Diuraphis noxia Kurdjumov [RWA]) is one of the most invasive and detrimental pests, and host plant resistance is the most efficient approach to manage RWA. Wheat (Triticum aestivum L.) accessions resistant to RWA biotype 1 (RWA1) and biotype 2 (RWA2) were previously identified by screening wheat accessions available at the USDA‐ARS National Small Grains Collection. However, RWA biotypic variation necessitates a continuous search for sources of resistance to new RWA biotypes. The objective of this study was to identify wheat accessions resistant to all major RWA biotypes in the United States. A set of 172 RWA‐resistant wheat accessions, mainly Iranian landraces, were evaluated for responses to five predominant U.S. biotypes—RWA1, RWA2, RWA3, RWA6, and RWA8—in controlled environments. Of these, 137 accessions showed homogeneous or heterogeneous resistance to at least one biotype, and 14 of them were resistant or highly resistant to all five biotypes. Another set of 19 accessions were resistant or highly resistant to two to four biotypes. These RWA‐resistant accessions are valuable sources for RWA resistance improvement, and further purification of some accessions and characterization of the underlying RWA resistance genes are imperative for their utilization in wheat breeding.

Variation of seed oil content, oil yield, and fatty acids profile in Iranian Nigella sativa L. landraces

Since there are several diverse landraces across Iran, screening the landraces with high production may lead to finding superior genotype(s) for the future conventional breeding programs. Thus, the aims of this study was to investigate the variation of oil content, yield, and profile of fatty acids in Iranian landraces of Nigella sativa L. Seed yield, oil content and oil yield significantly differed among landraces. The highest seed and oil yields were obtained from Semirom (1250 and 332 kg ha−1). Twelve different fatty acids were detected. Linoleic acid (18:2) had the highest concentration in oil of N. sativa landraces with a range of 48–55 %. After linoleic acid, oleic (18:2) and palmitic (16:0) acids, with an average of 22 and 13 %, accounted for the highest percentage of seed oil compared with the other fatty acids. Saturated fatty acids (∑SFA) was significantly different among the landraces and included 19–22 % and 21–24 % of total fatty acids. Double bond index (DBI) was significantly different among landraces and ranged between 136.5–145.3 in 2018 and 127.5–134.5 in 2019. The Gardmiran landrace had the highest Iodine value (IV) (111.7, an average of two years) and Khaf landrace had the lowest IV (105.7, in average of two years) compared with the other landraces. Cluster analysis indicated that the landraces can be divided into three groups; (1) high yield (>1000 kg ha-1 seeds and >250 kg ha−1 oil), (2) medium yield (700–1000 kg ha−1 seeds and 190–250 kg ha−1 oil), and low yield (<700 kg ha−1 seeds and <190 kg ha−1 oil) landraces. Iranian landraces were similar in fatty acid compositions and conventional breeding methods may not be a good choice to improve a special fatty acid. However, a large variations existed in seed and oil yield among the landraces for the future conventional breeding programs.

Puroindoline (Pina-D1 and Pinb-D1) and waxy (Wx-1) genes in Iranian bread wheat (Triticum aestivum L.) landraces

Grain hardness and starch are two of the most important factors that determine the end-use quality of bread wheat (Triticum aestivum L.) grain. The grain hardness and amylose content are controlled by the puroindolines (Pina-D1 and Pinb-D1) genes, located on chromosomes 5D, and waxy (Wx-A1, -B1 and -D1) genes, located on chromosomes 7A, 4A and 7D. A total of 160 Iranian landraces from the Germplasm Bank of the International Maize and Wheat Improvement Center were evaluated for grain hardness using near infrared spectroscopy to predict the particle size index (PSI). In addition, molecular markers were used to evaluate the states of the corresponding genes. Eight accessions were found to have a hard texture (predicted PSI < 45%); however, only two could be explained by null alleles either in Pina-D1 or Pinb-D1. Additionally, 152 accessions had semi-hard textures (predicted PSI range of 45% to 55%). For the Wx gene, only one accession (CWI 67665) showed the null Wx-D1b allele, while two accessions (CWI 67747 and CWI 57684) were null for Wx-B1b. Single nucleotide polymorphism and sequence tag site marker techniques were used. Our findings further indicate the importance of using these landraces for grain quality improvement in breeding programs.

Whole Genome Diversity, Population Structure, and Linkage Disequilibrium Analysis of Chickpea (Cicer arietinum L.) Genotypes Using Genome-Wide DArTseq-Based SNP Markers.

Characterization of genetic diversity, population structure, and linkage disequilibrium is a prerequisite for proper management of breeding programs and conservation of genetic resources. In this study, 186 chickpea genotypes, including advanced “Kabuli” breeding lines and Iranian landrace “Desi” chickpea genotypes, were genotyped using DArTseq-Based single nucleotide polymorphism (SNP) markers. Out of 3339 SNPs, 1152 markers with known chromosomal position were selected for genome diversity analysis. The number of mapped SNP markers varied from 52 (LG8) to 378 (LG4), with an average of 144 SNPs per linkage group. The chromosome size that was covered by SNPs varied from 16,236.36 kbp (LG8) to 67,923.99 kbp (LG5), while LG4 showed a higher number of SNPs, with an average of 6.56 SNPs per Mbp. Polymorphism information content (PIC) value of SNP markers ranged from 0.05 to 0.50, with an average of 0.32, while the markers on LG4, LG6, and LG8 showed higher mean PIC value than average. Unweighted neighbor joining cluster analysis and Bayesian-based model population structure grouped chickpea genotypes into four distinct clusters. Principal component analysis (PCoA) and discriminant analysis of principal component (DAPC) results were consistent with that of the cluster and population structure analysis. Linkage disequilibrium (LD) was extensive and LD decay in chickpea germplasm was relatively low. A few markers showed r2 ≥ 0.8, while 2961 pairs of markers showed complete LD (r2 = 1), and a huge LD block was observed on LG4. High genetic diversity and low kinship value between pairs of genotypes suggest the presence of a high genetic diversity among the studied chickpea genotypes. This study also demonstrates the efficiency of DArTseq-based SNP genotyping for large-scale genome analysis in chickpea. The genotypic markers provided in this study are useful for various association mapping studies when combined with phenotypic data of different traits, such as seed yield, abiotic, and biotic stresses, and therefore can be efficiently used in breeding programs to improve chickpea.

Chemical Compositions and Antioxidant Activity of Essential Oils from Inflorescences of Two Landraces of Hyssop [Hyssopus officinalis L. subsp. angustifolius (Bieb.)] Cultivated in Southwestern, Iran

Hyssop [Hyssopus officinalis L. subsp. angustifolius (Bieb.)] belonging to the family Lamiaceae, is an important medicinal and aromatic plant in Iranian folk medicine. The herb grows wildly in the alpine regions from northwestern to southwestern of Iran. A GC-FID and GC/MS analysis of essential oils isolated from the inflorescences of two Iranian landraces of this herb including white and purple flowers identified 25, and 22 constituents, respectively (accounting for 98 % of the total oils). The essential oil yields were 0.40 and 0.45 ml/100 g based on the dry weight of plant material for white and purple flowers, respectively. The major constituents of the essential oil from purple landrace were cis-pinocamphone (55.14 %), β-pinene (17.06 %), and trans-pinocamphone (3.50 %). However, camphor (31.85 %), cis-pinocamphone (30.11%), β-pinene (12.26 %), and trans-pinocamphone (6.09 %) were the main compositions of the essential oil from white landrace of hyssop. Antioxidant activity of the essential oils was determined by DPPH assay and the essential oils of both landraces showed moderate antioxidant activity. This potential applicability can be used as antioxidant agents for food and pharmaceutical industries. The essential oils of the two studied hyssop landraces sourced in the alpine region of southwestern Iran were rich in oxygenated monoterpenes. Generally, the herb proved to be relatively good sources of chemical products and medicinal compounds such as camphor, pinocamphone and β-pinene that are widely used in food and drug industries.

Preliminary characterization for grain quality traits and high and low molecular weight glutenins subunits composition of durum wheat landraces from Iran and Mexico

Durum wheat landraces from Iran and Mexico were evaluated for important grain traits, gluten quality characteristics and ultimate baking performance. It was also characterized by SDS-PAGE for high and low molecular weight glutenins composition. Substantial phenotypic variation was observed for most traits, with promisingly useful variability identified for attributes that typically limit durum wheat from being used in industrial bread-making processes, such as gluten extensibility and actual baking performance. Promising genotypes with atypically enhanced extensibility and/or baking performance, independently, from high protein content were identified and can be considered as valuable parental stocks to be exploited in durum breeding programs targeting the widening of the end-uses of this grain. A significant number of novel glutenins subunit and/or subunit combinations were described. The Iranian group was found to be more diverse than the Mexican group, which is consistent with their respective evolution histories: The Mexican Creoles wheats represents a small sample of the variability that was present in the Iberian Peninsula when they were moved to Mexico while the Iranian landraces evolved very close to the center of Origin of durum wheat, maintained most of the variability that was developed in the region from the early days of durum wheat evolution.

Genomic Regions From an Iranian Landrace Increase Kernel Size in Durum Wheat.

Kernel size and shape are important parameters determining the wheat profitability, being main determinants of yield and its technological quality. In this study, a segregating population of 118 recombinant inbred lines, derived from a cross between the Iranian durum landrace accession “Iran_249” and the Iranian durum cultivar “Zardak”, was used to investigate durum wheat kernel morphology factors and their relationships with kernel weight, and to map the corresponding QTLs. A high density genetic map, based on wheat 90k iSelect Infinium SNP assay, comprising 6,195 markers, was developed and used to perform the QTL analysis for kernel length and width, traits related to kernel shape and weight, and heading date, using phenotypic data from three environments. Overall, a total of 31 different QTLs and 9 QTL interactions for kernel size, and 21 different QTLs and 5 QTL interactions for kernel shape were identified. The landrace Iran_249 contributed the allele with positive effect for most of the QTLs related to kernel length and kernel weight suggesting that the landrace might have considerable potential toward enhancing the existing gene pool for grain shape and size traits and for further yield improvement in wheat. The correlation among traits and co-localization of corresponding QTLs permitted to define 11 clusters suggesting causal relationships between simplest kernel size trait, like kernel length and width, and more complex secondary trait, like kernel shape and weight related traits. Lastly, the recent release of the T. durum reference genome sequence allowed to define the physical interval of our QTL/clusters and to hypothesize novel candidate genes inspecting the gene content of the genomic regions associated to target traits.

Bulked segregant RNA-sequencing (BSR-seq) identified a novel rare allele of eIF4E effective against multiple isolates of BaYMV/BaMMV.

A novel rare allele of the barley host factor gene eIF4E for BaMMV/BaYMV infection was identified in an Iranian landrace that showed broad resistance to barley yellow mosaic virus disease, and molecular markers facilitating efficient selection were developed. The soil-borne yellow mosaic virus disease caused by different strains of barley yellow mosaic virus (BaYMV) and barley mild mosaic virus (BaMMV) is a major threat to winter barley (Hordeum vulgare) production in Europe and East Asia. However, the exploration of resistant germplasm or casual genes for barley breeding is rather limited in relation to the rapid diversification of viral strains. Here, we identified an Iranian barley landrace 'HOR3298,' which represented complete resistance to BaYMV and BaMMV. In contrastto rym4 and rym5, which act as the predominant source in Europe and East Asia for breeding resistant cultivars over decades and which have been overcome by several virulent isolates, this landrace showed broad-spectrum resistance to multiple isolates of BaYMV/BaMMV in the fields of Germany and China. By employment of bulked segregant RNA sequencing, test for allelism, and haplotype analysis, a recessive resistance gene in 'HOR3298' was genetically mapped coincident with the host factor eukaryotic translation initiation factor 4E (eIF4E, causal gene of rym4 and rym5). The eIF4EHOR3298 allele encoded for a novel haplotype that contained an exclusive nucleotide mutation (G565A) in the coding sequence. The easily handled markers were developed based on the exclusively rare variation, providing precise selection of this allele. Thus, this work provided a novel reliable resistance source and the feasible marker-assisted selection assays that can be used in breeding for barley yellow mosaic virus disease resistance in cultivated barley.

Selection of basil (Ocimum basilicum L.) full-sib families from diverse landraces

Basil (Ocimum basilicum L.) is one of the most important culinary and aromatic plants in Iran. Surprisingly, no commercial cultivar is available across the country and farmers are cultivating landraces. The main purpose of the present study was to describe the diversity among and within landraces of sweet basil as well as developing new genotypes for cultivar development. Twenty two genotypes of basil including Iranian landraces and international cultivars were evaluated in a randomized complete block design with three replications in 2017. Three Iranian landraces, ‘Isfahan3’, ‘Birjand’ and ‘Malayer’ were recognized as superior landraces. Dry herb for them was recorded as 3309, 3191 and 3175 kg ha−1, respectively. Also, the content of essential oil in ‘Isfahan3’, ‘Birjand’ and ‘Malayer’ was obtained as 1.43, 1.85, and 1.79% (w/w on dry weight basis), respectively. Due to existence of high diversity among landraces, broad-sense heritability estimates were over 98% for all of the evaluated traits. Among these landraces, 14 full-sib families were produced via controlled pollination. In another experiment the full-sib families were compared. For all measured traits, there were highly significant differences among full-sib families. The best family in each landrace was selected for cultivar development in future breeding programs.

Characterization of Pm63, a powdery mildew resistance gene in Iranian landrace PI 628024.

A new powdery mildew resistance gene conferring a wide spectrum of resistance to Bgt isolates in the USA, Pm63 , was identified in Iranian wheat landrace PI 628024 and mapped to the terminal region of the long arm of chromosome 2B. Powdery mildew is a globally important wheat disease causing severe yield losses, and host resistance is the preferred strategy for managing this disease. The objective of this study was to characterize a powdery mildew resistance gene in Iranian landrace PI 628024, which exhibited a wide spectrum of resistance to representative Blumeria graminis f. sp. tritici (Bgt) isolates collected from different regions of the USA. An F2 population and F2:3 lines derived from the cross PI 628024 × CItr 11349 were used in this study, and genetic analysis indicated that a single dominant gene, designated Pm63, conferred resistance to Bgt isolate OKS(14)-B-3-1. Linkage analysis located Pm63 to an interval of about 13.1Mb on the long arm of chromosome 2B, spanning 710.3-723.4Mb in the Chinese Spring reference sequence. Bin mapping assigned Pm63 to the terminal bin 2BL6-0.89-1.0, 1.1cM proximal to STS marker Xbcd135-2 and 0.6cM distal to SSR marker Xstars419. Allelism tests indicated that Pm63 is a new powdery mildew resistance gene, which differs from other genes in the terminal bin by origin, genomic location, and responses to a set of 16 representative US Bgt isolates. Pm63 can be widely used to enhance powdery mildew resistance in the Great Plains, western, and southeastern regions of the USA.

Chemotypes and morpho-physiological characters affecting essential oil yield in Iranian cumin landraces

The cumin essential oil is used in the food and pharmaceutical industry. Despite the large commercial production of cumin in Iran, there is no comprehensive study on quality and quantity of its essential oil. This experiment was conducted to study morpho-phenological and physiological characters affecting essential oil yield and to identify possible chemotypes in Iranian cumin landraces. Eyvanekey landrace with the highest essential oil content and yield had the highest carotenoids and total chlorophyll contents and oil body number in the cell. The results of the GC-MS chromatography showed that the identified components were classified into four organic compounds including monoterpenes, oxygenated monoterpenes, sesquiterpenes and others. According to essential oil compositions, cumin landraces were clustered in two chemotypes including low cuminal / high monoterpenes and high cuminal / low monoterpenes chemotypes, indicating a significant difference in essential oil quality. Khansar landrace with the highest cuminal content was introduced as the best Iranian landrace in terms of essential oil quality. Neronine alkaloid was identified in cumin essential oil for the first time, and Jat landrace is a novel plant source of neronine alkaloid. Essential oil yield had the positive regression and correlation coefficients with SWM (seed weight per m2) and days to maturity which indicate that these characters are suitable selection indexes to improve cumin essential oil yield. A negative relationship between the cuminal content and limonene synthase gene expression (r = -0.55*) was observed. So, it was concluded that landraces having low limonene synthase gene expression are favorable for marketing.

Chemical Variation in the Essential Oil of Iranian Rosa damascena Landraces under Semi-arid and Cool Conditions

In present study, essential oil content and compositions of 49 Iranian landraces of Damask rose (Rosa damascena Mill.) was investigated. Essential oils were isolated with distillation method and component composition was determined with gas chromatography–mass spectrometry (GC/MS). Twenty main compounds were identified in the essential oil representing about 90% of the total oil. The major components were found to be n-nonadecane (with seasonal range of 32.4-36.1%), n-heneicosane (20.3-22.1%), citronellol (6.6-10.3%), n-hexadecanol (6.4-6.7%) and n-tricosane (5.9-7.0%). The percentages of citronellol and geraniol as the two important compounds of the rose oil quality in 2008 were more than their percentages in 2007. Therefore, it can be inferred that dry conditions increased the aliphatic compounds percentages and reduced alcoholic compounds in the rose oil. Despite the differences in origin sites, climates and ecological conditions among landraces, the results of cluster analysis (CA) revealed that all of the landraces of Damask rose with exception of KB1 and AK1 showed more than 90% similarity in their major oil composition. The result of principal component analysis (PCA) revealed that the landraces with the highest percentage of citronellol and geraniol components usually show extreme values (positive or negative) of PC1 and PC2.

Dn10, a New Gene Conferring Resistance to Russian Wheat Aphid Biotype 2 in Iranian Wheat Landrace PI 682675

Russian wheat aphid [RWA, Diuraphis noxia (Mordvilko)] is a serious pest of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) that causes heavy yield losses in many countries, and RWA biotype 2 (RWA2) is virulent to most RWA resistance genes. The objective of this study was to characterize a gene for resistance to RWA2 in Iranian landrace PI 682675, a single‐plant selection from PI 624151. F2:3 and F3:4 families derived from cross PI 682675 × Zhengyou 6 were used to map the resistance gene. PI 682675 carries a dominant resistance gene, Dn10, flanked by simple sequence repeat markers Xgwm437 and Xwmc488 on chromosome 7DL. Physical mapping indicated that Dn10 resides in bin 7DL 0.1 to 0.77, whereas Dn2401 and Dn626580 that also confer resistance to RWA2 were physically mapped to 7DS. Allelism tests showed that Dn10 was located ∼17.4 cM from Dn2401 and 22.2 cM from Dn626580. Dn10 is a new resistance gene that should be used widely in wheat breeding.

Expression patterns of the genes encoding fructan active enzymes (FAZYs) alongside fructan constituent profiles in chicory (Cichorium intybus L.): effects of tissue and genotype variations

Dynamic transcriptional variations of genes encoding fructan active enzymes (FAZYs; 1-SST, 1-FFT, 1-FEHI, 1-FEHII) alongside their potential contributions regarding production/degradation of various carbohydrates (i.e., fructose, glucose, sucrose, 1-kestose, and inulin) were scrutinized in the two distinct genotypes of chicory (Cichorium intybus L.) namely “Germany variety” and “Iranian landrace”, at flowering stage. Germany variety accumulated overall more amounts of fructose, sucrose, and inulin, while Iranian landrace contained the highest proportion of 1-kestose, and glucose. Furthermore, both 1-SST and 1-FFT genes were dramatically up-regulated in the root-harvested samples of both genotypes, though maximum transcripts of 1-SST and 1-FFT were respectively detected in landrace and Germany variety, suggesting a cultivar- and tissue-dependent phenomenon. Instead, in both genotypes, maximum transcript levels of 1-FEHI were detected in stem, while root, flower and leaf tissues possessed inferior magnitudes. Considering 1-FEHII, both genotypes exhibited a down-regulated behavior in four tissues (excluding landrace stem). Meanwhile, the chicory MYB transcription factor (CiMYB17) transcriptionally fluctuated among four tissues of both chicory genotypes, and exhibited significant correlation only with 1-FEHI in Germany, a moderate correlation with 1-FEHI in landrace, and lower associations with 1-SST, 1-FFT, and 1-FEHII, indicating its trivial regulatory roles in the complex regulation of FAZY gene expression, and subsequently biosynthesis/degradation of fructans under normal circumstances. Regarding landrace, both 1-SST and 1-FFT correlated only with glucose, while for Germany variety, 1-SST had a strong association with inulin, 1-ketose, alongside glucose, and 1-FFT had a strong correlation only with glucose. However, both 1-FEHI and 1-FEHII exhibited no considerable associations with all the carbohydrates studied. Notably, 1-FEHII negatively correlated with inulin content, indicating an “antagonistic” effect between inulin accumulation/production and 1-FEHII activity. The results, overall, demonstrated that variations in genotypes and/or tissues under study can synergistically/antagonistically influence expression patterns of FAZY genes alongside production/degradation of the corresponding fructans.

Applicability of CAAT Box-derived Polymorphism (CBDP) Markers for Analysis of Genetic Diversity in Durum Wheat

Progress in plant molecular tools has been resulted in the development of gene-targeted and functional marker systems. CAAT box region is a different pattern of nucleotides with a consensus sequence, GGCCAATCT, which situated upstream of the start codon of eukaryote genes and plays an important role during transcription. In the present study, several CAAT box-derived polymorphism (CBDP) primers were used for fingerprinting in mini-core collection of durum wheat (including internationally developed breeding lines and Iranian landraces). Twelve selected primers amplified 98 loci, of which all were polymorphic. The average values of the polymorphism information content (PIC) and resolving power (Rp) were 0.31 and 9.16, respectively, indicating a high level of variability among studied genotypes. Analysis of molecular variance (AMOVA) indicated that 92% of the total variation resided among populations. The values of the percentage polymorphic bands (PPL), the observed (Na) and effective (Ne) number of alleles, Nei’s gene diversity (He) and Shannon’s information index (I) for Iranian landraces were higher than the breeding lines. The Fandendrogram obtained by cluster analysis grouped all individuals into three main clusters. Our results showed a remarkable level of genetic diversity among studied durum wheat, especially among Iranian landraces, which can be interest for future breeding programs. More importantly, the present study also revealed that CBDP technique was efficient and powerful tool to assess genetic diversity in wheat germplasm. Hence, this technique could be employed individually or in combination with other molecular markers to evaluate genetic diversity and relations among different species.