The Bo1-specific PCR marker AWW5L7 is predictive of boron tolerance status in a range of exotic durum and bread wheats

Genome ◽  
2008 ◽  
Vol 51 (12) ◽  
pp. 963-971 ◽  
Author(s):  
Thorsten Schnurbusch ◽  
Peter Langridge ◽  
Tim Sutton

High soil boron (B) constitutes a major soil problem in many parts of the world, particularly in low-rainfall areas and land under irrigation. Low accumulation of B in the shoot or grain of cereal crops is correlated with the maintenance of biomass production and grain yield under high B conditions, suggesting that this trait is an important component of field tolerance. A novel screening protocol to measure B accumulation in aerated and supported hydroponics was validated using a set of known and exotic bread wheat ( Triticum aestivum L.) and durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husn.) accessions. Furthermore, B accumulation in two Triticum urartu Tumanian ex Gandilyan and 54 Triticum monococcum L. accessions was measured and showed considerable phenotypic variation. However, B accumulation in these lines was higher than that observed in the most tolerant durum or bread wheats. Mapping of high B tolerance in the durum population AUS14010/Yallaroi revealed a locus possibly allelic to Bo1, a major source of B toxicity tolerance previously identified in bread wheat. Here, we show that the Bo1-specific codominant PCR marker AWW5L7 is predictive of B tolerance status among exotic durum and bread wheat accessions. All tolerant durum accessions assayed carried very similar AWW5L7 marker fragments, indicating wide distribution of this allele among tolerant durum wheats. Three bread wheat accessions had tolerance that was independent of Bo1 and is probably located on chromosome 4A. These lines represent a valuable genetic resource for B toxicity tolerance breeding in wheat.

2005 ◽  
Vol 56 (12) ◽  
pp. 1355 ◽  
Author(s):  
Anna Mantzavinou ◽  
Penelope J. Bebeli ◽  
Pantouses J. Kaltsikes

Using the random amplified polymorphic DNA (RAPD) method, the genetic diversity of 19 Greek landraces and 9 cultivars of durum wheat [Triticum turgidum L. var. durum (Desf.)] was studied. Two commercial bread wheat (Triticum aestivum L.) cultivars and one genotype of Triticum monococcum L. were also included in the study. Eighty-seven arbitrary primers (10-mer) were evaluated in a preliminary experiment and 15 of them were selected for the main experiments based on the quality and reliability of their amplification and the polymorphism they revealed. A total of 150 DNA bands were obtained, 125 (83.3%) of which were polymorphic. On average, 10 DNA bands were amplified per primer, 8.3 of which were polymorphic. The genetic similarity between all pairs of genotypes was evaluated using the Jaccard’s or Nei and Li’s coefficients; the values of the former ranged from 0.153 to 0.973 while those of the latter were slightly higher (0.265–0.986). Cluster analysis was conducted by the UPGMA and the Njoin methods. Both methods broadly placed 26 durum genotypes into 1 branch while the other branch consisted of 2 subgroups: 1 included the 2 bread wheat cultivars; the other 1 consisted of 2 durum landraces, ‘Kontopouli’ and ‘Mavrotheri-Chios’, which showed an intruiging behaviour sharing bands with the bread wheat cultivars. The T. monococcum cultivar stood apart from all other genotypes.


2004 ◽  
Vol 55 (3) ◽  
pp. 321 ◽  
Author(s):  
J. A. Kirkegaard ◽  
S. Simpfendorfer ◽  
J. Holland ◽  
R. Bambach ◽  
K. J. Moore ◽  
...  

The effect of previous crops (oilseed, legume, and cereal) on the incidence and severity of crown rot (Fusarium pseudograminearum, Fp) and yield of wheat was investigated in 3 field studies in northern New South Wales. The experiments were designed to compare the effectiveness of the Brassica break crops canola (Brassica napus L.) and mustard (B. juncea L.) with chickpea (Cicer arietinum L.) on reduction of Fp in subsequent wheat crops. Responses to previous broadleaf and cereal crops were investigated in Fp-tolerant bread wheat (Triticum aestivum L.) and Fp-susceptible durum wheat [Triticum turgidum L. ssp. durum (Dest.)]. In all experiments, broadleaf break crops increased the yield of Fp-susceptible durum wheat compared with durum after cereals (by 0.24–0.89 t/ha). The same response was observed for the Fp-tolerant wheat at 2 of the 3 sites (0.71 and 0.78 t/ha), with a lower yield (0.13 t/ha) after break crops than after cereals at one site during a drought. The yield of the Fp-susceptible durum wheat was generally higher after brassicas than after chickpea (yield advantage 0.27–0.58�t/ha), whereas there was no such difference in the tolerant wheat variety. In most cases, these yield responses to the previous crops were closely related to the severity of Fp infection. Overall yield of susceptible durum wheat was reduced by 1% for each 1% increase in Fp severity at harvest. Residual water and nitrogen (N) did not explain responses to previous crops, although common root rot (Bipolaris sorokiniana) may have contributed to some of the responses at the sites. There was little evidence that the lower disease and higher yield following brassicas compared with chickpea was related to suppression of Fp by biofumigation. More plausible explanations are that residual cereal residues decomposed more rapidly under dense Brassica canopies thus reducing Fp inoculum, that Fp severity was increased following chickpea due to higher soil N status, or that brassicas resulted in soil/residue biology that was less conducive to Fp inoculum survival. Evidence for the latter was provided by consistently higher levels of Trichoderma spp. isolated from wheat following brassicas compared with chickpea or cereals. Irrespective of the mechanisms involved, the results demonstrate that Brassica oilseeds provide an effective break crop for crown rot in northern NSW. Furthermore, brassicas may provide an excellent alternative rotation crop to chickpea for high value durum wheat due to an apparent capacity to more effectively reduce the severity of crown rot infection in subsequent crops.


2021 ◽  
Vol 8 (1) ◽  
pp. 3-13
Author(s):  
I. Balashova ◽  
V. Fait

Aim. To identify and evaluate allele frequencies of Ppd-D1a, Ppd-B1a, Ppd-B1c and Ppd-1 of the genotypes of spring bread wheat varieties from various climatic zones. Methods. DNA isolation, allele-specific PCR, electrophoresis in agarose and polyacrylamide gel, statistical analysis. Results. 137 varieties of spring bread wheat of various origin were detected to identify Ppd-1 genotypes of Ppd-D1a, Ppd-B1a and Ppd-B1c allele carriers. The results for the total sampling of the varieties under investigation and the sampling of Asian varieties yielded six different Ppd-1 genotypes in each. As for samplings of other regions, there were from two (Mexico) to four (Europe, the USA, Canada, Ukraine) Ppd-1 genotypes. In the total sampling of varieties, there was a high incidence (20.5 %) of genotypes, dominant only in allele Ppd-D1a, varying from 0 (Russia) to 85.0 % (Mexico). The incidence of the genotypes with monogenically dominant Ppd-B1a (7.3 %) or Ppd-B1c (5.1 %) in the total sampling, was considerably lower. These genotypes were most common for the sampling of the varieties from the USA and Canada (25.0 and 16.7 % respectively). Digenically dominant Ppd-D1a Ppd-B1a genotypes were found in the total sampling with relatively low incidence (7.3 %), and were notable for the varieties from Asia (33.4 %), Mexico (15.0 %), Ukraine (13.1 %), and Europe (3.1 %). The di genically dominant genotype Ppd-D1a Ppd-B1с was found only in the Japanese variety Konosu-25. Gene Ppd-A1 was present in all the spring varieties under investigation in its recessive state. Conclusions. Out of three dominant alleles in the studied sampling, the highest incidence was noted for allele Ppd-D1a (28.5 %). All the varieties from Mexico, present in the set, carry this allele. At the same time, it was not found in any variety from Russia. Allele Ppd-B1a was detected in the varieties from all the regions with the incidence of 7.7 (Russia) – 44.4 % (Asia). Allele Ppd-B1c was sporadically present in the varieties from Russia, Ukraine, the USA, Japan, and Brazil, and its incidence in the total sampling was insignificant (5.8 %). The varieties, identified by the allelic status of Ppd-1 genes, may be used as donors for selection and determination of the influence of alleles for each gene by the development rate and related economically valuable traits of bread wheat.


Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 440
Author(s):  
Edossa Fikiru Wayima ◽  
Ayalew Ligaba-Osena ◽  
Kifle Dagne ◽  
Kassahun Tesfaye ◽  
Eunice Magoma Machuka ◽  
...  

Acid soils and associated Al3+ toxicity are prevalent in Ethiopia where normally Al3+-sensitive durum wheat (Triticum turgidum ssp durum Desf.) is an important crop. To identify a source of Al3+ tolerance, we screened diverse Ethiopian durum germplasm. As a center of diversity for durum wheat coupled with the strong selection pressure imposed by extensive acid soils, it was conceivable that Al3+ tolerance had evolved in Ethiopian germplasm. We used a rapid method on seedlings to rate Al3+ tolerance according to the length of seminal roots. From 595 accessions screened using the rapid method, we identified 21 tolerant, 180 intermediate, and 394 sensitive accessions. When assessed in the field the accessions had tolerance rankings consistent with the rapid screen. However, a molecular marker specific for the D-genome showed that all accessions rated as Al3+-tolerant or of intermediate tolerance were hexaploid wheat (Triticum aestivum L.) that had contaminated the durum grain stocks. The absence of Al3+ tolerance in durum has implications for how Al3+ tolerance evolved in bread wheat. There remains a need for a source of Al3+-tolerance genes for durum wheat and previous work that introgressed genes from bread wheat into durum wheat is discussed as a potential source for enhancing the Al3+ tolerance of durum germplasm.


2009 ◽  
Vol 36 (12) ◽  
pp. 1110 ◽  
Author(s):  
Tracey Ann Cuin ◽  
Yu Tian ◽  
Stewart A. Betts ◽  
Rémi Chalmandrier ◽  
Sergey Shabala

Wheat breeding for salinity tolerance has traditionally focussed on Na+ exclusion from the shoot, but its association with salinity tolerance remains tenuous. Accordingly, the physiological significance of shoot Na+ exclusion and maintenance of an optimal K+ : Na+ ratio was re-evaluated by studying NaCl-induced responses in 50 genotypes of bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. ssp. durum) treated with 150 mM NaCl. Overall, Na+ exclusion from the shoot correlated with salinity tolerance in both species and this exclusion was more efficient in bread compared with durum wheat. Interestingly, shoot sap K+ increased significantly in nearly all durum and bread wheat genotypes. Conversely, the total shoot K+ content declined. We argue that this increase in shoot sap K+ is needed to provide efficient osmotic adjustment under saline conditions. Durum wheat was able to completely adjust shoot sap osmolality using K+, Na+ and Cl–; it had intrinsically higher levels of these solutes. In bread wheat, organic osmolytes must contribute ~13% of the total shoot osmolality. In contrast to barley (Hordeum vulgare L.), NaCl-induced K+ efflux from seedling roots did not predict salinity tolerance in wheat, implying that shoot, not root K+ retention is important in this species.


Genome ◽  
2006 ◽  
Vol 49 (9) ◽  
pp. 1131-1139 ◽  
Author(s):  
Catherine Ravel ◽  
Sébastien Praud ◽  
Alain Murigneux ◽  
Aurélie Canaguier ◽  
Frédéric Sapet ◽  
...  

Information on single-nucleotide polymorphisms (SNPs) in hexaploid bread wheat is still scarce. The goal of this study was to detect SNPs in wheat and examine their frequency. Twenty-six bread wheat lines from different origins worldwide were used. Specific PCR-products were obtained from 21 genes and directly sequenced. SNPs were discovered from the alignment of these sequences. The overall sequence polymorphism observed in this sample appears to be low; 64 single-base polymorphisms were detected in ~21.5 kb (i.e., 1 SNP every 335 bp). The level of polymorphism is highly variable among the different genes studied. Fifty percent of the genes studied contained no sequence polymorphism, whereas most SNPs detected were located in only 2 genes. As expected, taking into account a synthetic line created with a wild Triticum tauschii parent increases the level of polymorphism (101 SNPs; 1 SNP every 212 bp). The detected SNPs are available at http://urgi.versailles.inra.fr/GnpSNP . Data on linkage disequilibrium (LD) are still preliminary. They showed a significant level of LD in the 2 most polymorphic genes. To conclude, the genome size of hexaploid wheat and its low level of polymorphism complicate SNP discovery in this species.


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