Ionic relations and osmotic adjustment in durum and bread wheat under saline conditions

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.

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 31 (11) ◽  
pp. 1105 ◽  
Author(s):  
Megan P. Lindsay ◽  
Evans S. Lagudah ◽  
Ray A. Hare ◽  
Rana Munns

Salinity affects durum wheat [Triticum turgidum L. ssp. durum (Desf.)] more than it affects bread wheat (Triticum aestivum L.), and results in lower yield for durum wheat cultivars grown on salt-affected soils. A novel source of salt tolerance in the form of a sodium exclusion trait, identified previously in a screen of tetraploid wheat germplasm, was mapped using a QTL approach. The trait, measured as low Na+ concentration in the leaf blade, was mapped on a population derived from a cross between the low Na+ landrace and the cultivar Tamaroi. The use of AFLP, RFLP and microsatellite markers identified a locus, named Nax1 (Na exclusion), on chromosome 2AL, which accounted for approximately 38% of the phenotypic variation in the mapping population. Markers linked to the Nax1 locus also associated closely with low Na+ progeny in a genetically unrelated population. A microsatellite marker closely linked to the Nax1 locus was validated in genetically diverse backgrounds, and proven to be useful for marker-assisted selection in a durum wheat breeding program.


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.


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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ghader Mirzaghaderi ◽  
Zinat Abdolmalaki ◽  
Rahman Ebrahimzadegan ◽  
Farshid Bahmani ◽  
Fatemeh Orooji ◽  
...  

AbstractDue to the accumulation of various useful traits over evolutionary time, emmer wheat (Triticum turgidum subsp. dicoccum and dicoccoides, 2n = 4x = 28; AABB), durum wheat (T. turgidum subsp. durum, 2n = 4x = 28; AABB), T. timopheevii (2n = 4x = 28; AAGG) and D genome containing Aegilops species offer excellent sources of novel variation for the improvement of bread wheat (T. aestivum L., AABBDD). Here, we made 192 different cross combinations between diverse genotypes of wheat and Aegilops species including emmer wheat × Ae. tauschii (2n = DD or DDDD), durum wheat × Ae. tauschii, T. timopheevii × Ae. tauschii, Ae. crassa × durum wheat, Ae. cylindrica × durum wheat and Ae. ventricosa × durum wheat in the field over three successive years. We successfully recovered 56 different synthetic hexaploid and octaploid F2 lines with AABBDD, AABBDDDD, AAGGDD, D1D1XcrXcrAABB, DcDcCcCcAABB and DvDvNvNvAABB genomes via in vitro rescue of F1 embryos and spontaneous production of F2 seeds on the Fl plants. Cytogenetic analysis of F2 lines showed that the produced synthetic wheat lines were generally promising stable amphiploids. Contribution of D genome bearing Aegilops and the less-investigated emmer wheat genotypes as parents in the crosses resulted in synthetic amphiploids which are a valuable resource for bread wheat breeding.


2000 ◽  
Vol 51 (1) ◽  
pp. 69 ◽  
Author(s):  
R. Munns ◽  
R. A. Hare ◽  
R. A. James ◽  
G. J. Rebetzke

Durum wheat (AB genomes) is more salt-sensitive than bread wheat (ABD genomes), a feature that restricts its expansion into areas with sodic or saline soils. Salt tolerance in bread wheat is linked with a locus on the D genome that results in low Na+ uptake and enhanced K+/Na+ discrimination. In order to introduce salt tolerance into current durum wheats from sources other than the D genome, a search for genetic variation in salt tolerance was made across a wide range of tetraploids representing 5 Triticum turgidum sub-species (durum, carthlicum, turgidum, turanicum, polonicum). Selections were screened for low Na+ uptake and enhanced K+/Na+ discrimination. This was assessed in seedlings grown in 150 mМ NaCl with supplemental Ca2+, by measuring the Na+ and K+ accumulated in the blade of a given leaf over 10 days. Large and repeatable genetic variation was found. Low Na+ accumulation and high K+/Na+ discrimination of similar magnitude to that of bread wheat was found in the sub-species durum. These selections have the potential for improving salt tolerance in durum wheat breeding programs.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1482
Author(s):  
Silvia Pampana ◽  
Alessandro Rossi ◽  
Iduna Arduini

Winter cereals are excellent candidates for biosolid application because their nitrogen (N) requirement is high, they are broadly cultivated, and their deep root system efficiently takes up mineral N. However, potential N leaching from BS application can occur in Mediterranean soils. A two-year study was conducted to determine how biosolids affect biomass and grain yield as well as N uptake and N leaching in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L. var. durum), and oat (Avena byzantina C. Koch). Cereals were fertilized at rates of 5, 10, and 15 Mg ha−1 dry weight (called B5, B10, and B15, respectively) of biosolids (BS). Mineral-fertilized (MF) and unfertilized (C) controls were included. Overall, results highlight that BS are valuable fertilizers for winter cereals as these showed higher yields with BS as compared to control. Nevertheless, whether 5 Mg ha−1 of biosolids could replace mineral fertilization still depended on the particular cereal due to the different yield physiology of the crops. Moreover, nitrate leaching from B5 was comparable to MF, and B15 increased the risk by less than 30 N-NO3 kg ha−1. We therefore concluded that with specific rate settings, biosolid application can sustain yields of winter cereals without significant additional N leaching as compared to MF.


2015 ◽  
Vol 102 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Gordana Branković ◽  
Vesna Dragičević ◽  
Dejan Dodig ◽  
Desimir Knežević ◽  
Borislav Kobiljski ◽  
...  

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