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Chinese endemic wheat landraces possess unique morphological features and desirable traits, useful for wheat breeding. It is important to clarify the relationship among these landraces. In this study, 21 accessions of the four Chinese endemic wheat landrace species were investigated using single-copy genes encoding plastid Acetyl-CoA carboxylase (Acc-1) and 3-phosphoglycerate kinase (Pgk-1) in order to estimate their phylogenetic relationship. Phylogenetic trees were constructed using maximum parsimony (MP), maximum likelihood (ML) and Bayesian, and TCS network and gene flow values. The A and B genome sequences from the Pgk-1 loci indicated that three accessions of Triticum petropavlovskyi were clustered into the same subclade, and the T. aestivum ssp. tibetanum and the Sichuan white wheat accessions were grouped into a separate subclade. Based on the Acc-1 gene, T. aestivum ssp. tibetanum and T. aestivum ssp. yunnanense were grouped into one subclade in the A genome; the B genome from T. petropavlovskyi and T. aestivum ssp. tibetanum, and the Sichuan white wheat complex and T. aestivum ssp. tibetanum were grouped in the same clades. The D genome of T. aestivum ssp. yunnanense clustered with T. petropavlovskyi. Our findings suggested that (1) T. petropavlovskyi is distantly related to the Sichuan white wheat complex; (2) T. petropavlovskyi, T. aestivum ssp. tibetanum and T. aestivum ssp. yunnanense are closely related; (3) T. aestivum ssp. tibetanum is closely related to T. aestivum ssp. yunnanense and the Sichuan white wheat complex; and (4) T. aestivum ssp. tibetanum may be an ancestor of Chinese endemic wheat landraces.

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The aphid Sitobion avenae F. is one of the most harmful pests of wheat growth in the world. A primary field screening test was carried out to evaluate the S. avenae resistance of 527 wheat landraces from Shaanxi. The results indicated that 25 accessions (4.74%) were resistant to S. avenae in the three consecutive seasons, of which accession S849 was highly resistant, and seven accessions were moderately resistant. The majority of S. avenae resistant accessions come from Qinling Mountains. Then, the genetic variability of a set of 33 accessions (25 S. avenae resistant and 8 S. avenae susceptible) originating from Qinling Mountains have been assessed by 20 morphological traits and 99 simple sequence repeat markers (SSRs). Morphological traits and SSRs displayed a high level of genetic diversity within 33 accessions. The clustering of the accessions based on morphological traits and SSR markers showed significant discrepancy according to the geographical distribution, resistance to S. avenae and species of accessions. The highly and moderately resistant landrace accessions were collected from the middle and the east part of Qinling Mountains with similar morphology characters, for example slender leaves with wax, lower leaf area, and high ear density. These S. avenae resistant landraces can be used in wheat aphid resistance breeding as valuable resources.

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The genetic diversity of 116 spring bread wheat cultivars released in Kazakhstan from 1929-2004 was studied by means of a genealogical analysis. The tendency of genetic diversity to change over time was traced by analysing a series of n ´ m matrices, where n is the number of released cultivars and m is the number of landrace ancestors. The pool of landrace ancestors of spring wheat cultivars in 1929-2004 contained a total of 114 landraces and old varieties, including 19 from Kazakhstan and Central Asia and 23 from neighbouring regions of Russia. The original ancestors differ significantly in frequency of presence and hence in their importance in the genepool of spring wheats cultivated in Kazakhstan. Significant differences in the contributions of dominant ancestors to cultivars for various regions have been revealed, showing that those ancestors were specifically adapted to different growing conditions. During the past 75 years, genetic diversity has increased due to the wide use of foreign materials in breeding programmes. A more detailed study has shown that during the period analysed, 15 landraces from Kazakhstan and neighbouring regions of Central Asia and Russia (35% of local germplasm) were lost from the pedigrees. The cluster structure of modern cultivars included in the Kazakhstan Official List (2002) was established. By analysing coefficients of parentage, significant differences in the genetic diversity of cultivars from various growing regions were revealed.

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The present investigation was carried out to study the distinct salt tolerance mechanism in two sets of material, Gly II transgenics and Kharchia landraces. The Gly II transgenics were developed for glyoxalase II (osglyII) gene (GenBank accession no. AY054407) from Oryza sativa through Agrobacterium mediated method in the background of wheat cultivar PBW 621. Kharchia 65 is a salt tolerant landrace derivative developed from Kharchia local which is native to saline soils of Rajasthan. The six wheat genotypes, viz. Kharchia local, Kharchia 65, PBW 621, G-2-2, G-3-4 and G-1-13 were evaluated for growth parameters, antioxidant enzymes and contents of glutathione, ascorbic acid, malondialdehyde (MDA), H2O2, sugars, chlorophyll, carotenoid, electrolyte leakage (EL) and Na+, K+ under control and two salt treatments (150 mM and 250 mM NaCl). The activities of antioxidant enzymes, glutathione, sugar content increased in both GlyII and Kharchia genotypes as compared to PBW 621. The GlyII activity increased (77–84%) in GlyII genotypes alongwith content of reduced glutathione (GSH) to maintain redox homeostasis. Apparently, GlyII and Kharchia genotypes exhibited minimum oxidative stress due to low content of MDA, H2O2, diminished EL and thereby causing less growth reduction and maintaining high chlorophyll and carotenoid level as compared to PBW 621. In addition, Gly II transgenic material and Kharchia lines showed less Na+ accumulation, greater seedling biomass and sugar content due to its salt tolerance mechanism. We infer that GlyII activity enhances GSH which play significant role in detoxifying ROS to establish stress homeostasis. The route for generation of GSH is via ascorbate-glutathione pathway mediated by glutathione reductase. Hence, GlyII transgenics and Kharchia genotypes can diminish salt stress following above mechanism.

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A large number of sorghum landraces possessing superior grain quality but poor yield potential are cultivated in South Africa, where sorghum is of regional importance as a main staple food. Agronomic traits of landraces and newly developed breeding lines from Southern Africa were evaluated under low-input and optimal conditions. Molecular evaluation was carried out on the basis of AFLPs and SSRs. The accessions clustered into two groups. Mean genetic similarity was estimated at 0.85 using AFLPs and 0.31 using SSRs. Genetic diversity was calculated at H=0.136 and DI=0.597 for landraces and H=0.140 and DI=0.580 for breeding varieties. The most promising accessions concerning yielding ability and grain quality were selected and introduced to a breeding programme.

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The High Molecular Weight Glutenin Subunits (HMW GS) in bread wheat landraces were studied using the SDS-PAGE technique. Out of the 32 landraces, 23 were homogeneous while nine showed heterogeneity with respect to the HMW glutenin subunits. Novel variants were observed in HMW GS in four of the landraces. One novel subunit coded by the Glu-B1x locus and two novel subunit pairs at the Glu-D1 locus were identified. A modified system of nomenclature over that of Payne and Lawrence (1983) is suggested for numbering the new subunits. Accordingly, the novel subunits are numbered as 7 1 ( Glu-B1x ) and 2+12 2 ; 5 1 +12 2 ; 5 2 +12 3 and 5 3 +12 3 ( Glu-D1x + y ) and the allelic designations are given as Glu-B1 bh for 7 1 +9; Glu-D1bp for 2+12 2 . Glu-D1bq for 5 1 +12; Glu-D1br for 5 1 +12 2 ; GluD1br for 5 2 +12 3 and GluD1bt for 5 3 +12 3 .

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Genotypes with various Vp-1B alleles perform different levels of pre-harvest sprouting (PHS) tolerance. In this study, 217 white-grained wheat cultivars, including 75 landraces, 39 historical cultivars, and 103 modern cultivars from five major regions of China, were examined to characterize the diversity of the Viviparous-1B ( Vp-1B ) locus associated with PHS tolerance. Four Vp-1B alleles were identified, three ( Vp-1Ba , Vp-1Bb and Vp-1Bc ) of which were previously reported in Chinese wheat cultivars. A new allele, Vp-1Be , was identified in the PHS tolerant landrace Hongheshangtou. Sequence analysis showed that Vp-1Be had an insertion of a 4-bp fragment, two SNPs, and a deletion of an 83-bp fragment compared with the nucleotide sequence of Vp-1Ba (AJ400713), all located in the third intron. Vp-1Be shared 97.80% similarity with the nucleotide sequence of AJ400713. The frequencies of Vp-1Ba , Vp-1Bb , and Vp-1Bc were 36.0%, 5.3%, and 57.3% in landraces; 23.1%, 7.7%, and 69.2% in historical cultivars; and 52.4%, 0%, and 47.6% in current cultivars, respectively.

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The objective of this study is the analysis of polymorphism in seed endosperm proteins (gliadins and glutenins) of Turkish cultivated einkorn wheat [Triticum monococcum ssp. monococcum] landraces. The genetic diversity of high-molecular-weight (HMW) glutenin subunits and the gliadin proteins in 10 landrace populations of cultivated einkorn wheat, originating from Turkey, was investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and ammonium lactic acid polyacrylamide gel electrophoresis (A-PAGE), respectively. For glutenins, the mean number of alleles, the mean number of effective alleles, the mean value of genetic diversity and the mean value of average genetic diversity were detected as 3.50, 2.98, 0.65 and 0.28, respectively. The genetic differentiation was 0.57, while gene flow was 0.19 between populations. For gliadins, the mean number of alleles, the mean number of effective alleles, the mean value of total genetic diversity and the genetic diversity within population were detected as 2.00, 1.21, 0.17 and 0.15, respectively. The genetic differentiation was 0.08, whereas gene flow was 6.15 between populations. STRUCTURE is a software package program for population genetic analysis, was used to infer population structures of landraces populations. The optimum value for K was obtained as 10. Considering the high number of proteins and genetic variation, and increased interest in organic products, the farming of einkorn wheat should be supported and conservation of germplasm in landraces should be maintained as important genetic resources. The landraces germplasm should be conserved for future crop improvement processes.

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The present study was conducted to determine the reactions of 88 bread wheat pure lines selected from landraces collected in Central Anatolian Region of Turkey against leaf rust (Puccinia triticina) under field conditions in 7 locations. GGE biplot analysis was used to determine the reactions of landrace genotypes against the disease. The GGE biplot explained 73.89% of total variation. Among the experimental locations, 6 (except for E3) were placed close to each other over the biplot graph, indicating two apparent mega-environments. The GGE biplot visually displayed the resistance and stability of the pure lines to leaf rust. The landrace genotypes L18, L19, L45, and L2 were identified as the most resistant/stable genotypes in all environments and L31 and L56 were the most susceptible/stable genotypes.

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In many world regions, osmotic and salt stresses are becoming the primary environmental conditions limiting successful establishment of crops. The old durum wheat landraces may provide a source of genes useful to enhance crop resilience to the abiotic stresses of dryland areas or foreseen as a result of climate change. With this in mind, in order to determine the effects of salt and osmotic stresses on durum wheat germination, an old Sicilian durum wheat landrace “Timilia” and a relatively recent cultivar “Mongibello” were investigated at various iso-osmotic solutions of NaCl and mannitol at osmotic potentials of: 0 – control, –0.125, –0.250, –0.500 and –0.750 MPa.

Under stress conditions, different germination and early growth behavior was observed in the two durum wheat genotypes. Timilia presented almost stable germination even at the highest osmotic stresses (96.7% and 88.3% seed germination at 0 and –0.750 MPa, respectively) showing a higher capacity of seed imbibition than Mongibello. The latter thus showed a higher sensitivity than the old landrace to the studied stresses. The variability ascertained in the response to salinity stress indicate that Timilia could be a source of interesting genes for breeding programs.

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