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Salinity induced inhibition in germination and early stages of cabbage (Brassica oleracea capitata L.) [two varieties (autumn cabbage and spring cabbage)] were measured in response to increasing NaCl concentration. The salinity (NaCl) concentrations in solution were 0 (control), 4.7, 9.4 and 14.1 dS m(-1). Different concentrations of salt stress had considerable effect on germination, germination rate (1/t50, where t50 is the time to 50% of germination), root and shoot lengths, root, shoot and plant fresh weight of cabbage. Final germination in cabbage (autumn cabbage and spring cabbage) showed significant inhibition with increasing salt stress up to 14.1 dS m(-1) NaCl. The required time for germination increased with increasing concentration of salt. The seedling growth was strongly inhibited by all salt levels, particularly at 14.1 dS m(-1). Furthermore Root growth was more affected then shoots growth by salt stress. Fresh weights of root, shoot and plant were also severely affected by different salinity treatments. Linear regression revealed a significant negative relationship between salinity and final germination, germination rate, root and shoot lengths and fresh weights of roots, shoots and plants.

Fifteen seed lots of Italian ryegrass cultivar RvP produced in 1976-1981 were stored at c. 5°C until 1999. Periodically samples were extracted and the final germination and germination rate were assessed. Controlled deterioration was used to assess vigour on a number of occasions. Most seed lots retained final germination above 50% even after 20 years storage. Germination rate generally declined with age but not at the same rate in all lots. There was initially no correlation of germination rate with final germination, but a significant positive relationship developed after about 10 years storage. Final germination after controlled deterioration (CD) was initially correlated with germination rate but when germination after CD was reduced to less than 50%, the germination rate was consistently low.

Knowledge of the extent and pattern of genetic diversity within and among populations is crucial to identify useful breeding materials and design appropriate collection and conservation strategies. Genetic diversity of 160 durum wheat (Triticum durum Desf) accessions was studied using 15 morpho-agronomic traits. The field studies for morphological characterization were undertaken at Adadi Maryam and Ginchi locations using randomized complete block design with two replications. The average linkage technique of clustering produced a more understandable portrayal of the 160 durum wheat accessions and released varieties by grouping them into seven clusters with inter-cluster D2 values ranged from 13.72 to 235. The highest genetic distances (253) was observed between cluster five (improved varieties) and cluster three accessions. The minimum genetic distance (13.72) was observed between cluster one and two both are landrace collections. Five of the 15 principal components accounted for more than 76.98% of the total variation in the Ethiopian durum wheat genotypes. The first principal components accounted for 32% of the total differences. In this study, there is a moderate genetic diversity between landraces collected from Tigray, Gonder, and Wello. Landraces from these areas can be used as a source of important pre-breeding material for future breeding programs. Key words: Landraces, durum wheat varieties, genetic distances, correlation, genetic diversity, morphological characters.

The rhizobacterial strain X33d was previously shown to suppress the growth of the weed great brome (Bromus diandrus Roth.). The aim of this work was to identify X33d, characterize its physiological activities, assess its specificity on different non-target crops, and its impact on the growth and the root architecture of great brome and durum wheat (Triticum durum Desf.) grown alone and together. Based on 16S rDNA sequencing, X33d was identified as Pseudomonas trivialis. The specificity assay, performed on a mixture of soil/sand/peat, highlighted the suppressive activity of P. trivialis X33d against great brome and the promoting effect on most of the considered crops, especially durum wheat. Although the growth of durum wheat on quartz sand was unaffected, P. trivialis X33d suppressed the growth and affected the root architecture of great brome, especially when co-seeded with durum wheat. Great brome plants inoculated with X33d and co-seeded with durum wheat showed low root biomass, short root systems and low surface area, volume and number of tips. Moreover, P. trivialis X33d synthesized indole-acetic acid (IAA) that could be involved both in great brome growth suppression and durum wheat growth promotion. Our results indicate that P. trivialis X33d could be exploited as a potential biocontrol agent against great brome without affecting the durum wheat growth. These results are discussed in relation to the competitive capability of great brome towards durum wheat.

The impact of salt stress under different salinity level (0, 50, 100, 150, 200 mMol of NaCl) on ten genotypes of durum wheat namely: Werd Bled, Hmira, Bidi, Arbi, INRAT 69, Agili, Derbassi and Bayatha, Karim and Maali was conducted. Germination rate were recorded daily using radicle extrusion as a criterion. Morphological studies root length, shoot length, fresh weight and dry weight of root and shoot were also measured. Analysis of variance (ANOVA) showed that germination rate of durum wheat genotypes was significantly affected by the salt stress. Results show a reduction of germination rate in response to the highest dose of NaCl for almost all the varieties except for Maali and Derbassi durum wheat cultivar in case150 and 200 mMol concentrations. After 6 days of germination, these lines showed germination percentage respectively of 70 and 60% against a rate of 0% for Bidi AP4 and Bayatha. For morphological traits, the effect of varieties was highly significant (P<0.01) on almost traits measured expect shoot dry weight, root fresh weight and root dry weight. Results show that all studied traits were significantly (P<0.001) reduced due to salt stress. The data showed that different level of salinity significantly affected the growth attributes by reducing root and shoot length for salinity below 50 mMol NaCl. Fresh weight and dry weight of root and shoot were reduced significantly with subsequent treatment. Key words: Durum wheat, germination, landraces, salt stress.

Global durum wheat consumption (Triticum durum Desf.) is ahead of its production. One reason for this is abiotic stress, e.g., drought. Breeding for resistance to drought is complicated by the lack of fast, reproducible screening techniques and the inability to routinely create defined and repeatable water stress conditions. Here, we report the first analysis of dissection of yield and yield-related traits in durum wheat in Pakistan, seeking to elucidate the genetic components of yield and agronomic traits. Analysis of several traits revealed a total of 221 (160 with logarithm of odds (LOD) > 2 ≤ 3 and 61 with LOD > 3) quantitative trait loci (QTLs) distributed on all fourteen durum wheat chromosomes, of which 109 (78 with LOD > 2 ≤ 3 and 31 with LOD > 3) were observed in 2016-17 (S1) and 112 (82 with LOD > 2 ≤ 3 and 30 with LOD > 3) were observed in 2017-18 (S2). Allelic profiles of yield QTLs on chromosome 2A and 7B indicate that allele A of Xgwm895 and allele B of Xbarc276 can enhance the Yd up to 6.16% in control and 5.27% under drought. Moreover, if combined, a yield gain of up to 11% would be possible.

Priming, a controlled-hydration treatment followed by redrying, improves the germination and emergence of seeds from many species. We compared osmotic and matric priming to determine which was the most effective treatment for improving broccoli seed germination and to gain a greater understanding of how seed vigor is enhanced by priming. Broccoli ( Brassica oleracea L. var. italica ) seeds were osmotically primed in polyethylene glycol (PEG 8000) at -1.1 MPa or matrically primed in a ratio of 1.0 g seed:0.8 g synthetic calcium silicate (Micro-Cel E):1.8 ml water at -1.2 MPa. In the laboratory, germination rates and root lengths were recorded from 5 to 42C and 10 to 35C, respectively. Broccoli seeds germinated poorly at &gt;35C. Root growth after germination was more sensitive to temperatures &gt;30C and &lt;15C than radicle emergence. Matric and osmotic priming increased germination rate in the laboratory, greenhouse, and field. However, matric priming had a greater effect on germination and root growth rates from 15 to 30C. Neither priming treatment affected minimum or maximum germination or root growth temperatures. Both priming treatments decreased the mean thermal time for germination by &gt;35%. The greater germination performance of matrically primed seeds was most likely the result of increased oxygen availability during priming, increased seed Ca content, or improved membrane integrity.

Durum wheat (Triticum durum Desf.) is an important crop in western Canada. In 2005, Arthrinium sacchari was frequently isolated from soil and durum wheat plants of the semi-arid fields of Swift Current, Saskatchewan, Canada (50°16'N, 107°44'W). The susceptibility of durum wheat to damping-off caused by this fungus was evaluated. To our knowledge, this is the first report of A. sacchari in North America (1) and the first mention of its association with durum wheat. DNA was extracted (MoBio Isolation Kit, Carlsbad, CA) from 2-week-old A. sacchari isolates (FBC.3, FBC.45, and FBC.143) grown on PDA. The internal transcribed spacer (ITS) of the rDNA was amplified from each isolate and sequenced (Plant Biotechnology Institute, Saskatoon, SK, Canada) and similarity analyses were performed using the BLAST search algorithm in GenBank. All three sequences (Accession Nos. EF076710, EF076711, and EF076712A) showed 99% similarity with A. sacchari (Accession No. AF393679). An in vitro assay was performed by placing 1-cm2 agar plugs containing mycelia of A. sacchari (FBC.3, FBC.45, and FBC.143) onto surface-sterilized durum. Surface-sterilized seeds inoculated in the same way with Fusarium graminearum or F. avenaceum were used as negative controls, and noninoculated surface-sterilized seeds were used as a positive control. A second in vitro assay involved inoculating the same isolates onto seeds placed in sterilized sandy soil. In both assays, 10 seeds per petri plate and three plates per treatment were used and plates were incubated at 21°C for 1 week in darkness. All experiments were performed twice. On PDA, preemergence damping-off was found in 60% of A. sacchari FBC.3, 55% of A. sacchari FBC.45 and FBC.143, 50% of F. avenaceum, and 58% of F. graminearum inoculated seeds. In sterilized soil, the incidence of preemergence damping-off ranged from 43 to 30%. Subsequent incubation over a period of 3 weeks resulted in 100% postemergence damping-off in A. sacchari FBC.45 and FBC.3 as well as in both Fusarium spp. inoculated controls, 60% postemergence damping-off in A. sacchari FBC.143, and no damping-off in the noninoculated control. Arthrinium and Fusarium spp. were reisolated only from symptomatic plants, satisfying Koch's postulates. In conclusion, durum wheat is highly susceptible to damping-off caused by A. sacchari, showing characteristic dark brown or violet lesions in infected tissues. A. sacchari was previously reported to be present in South America and eastern Asia. In China, it is considered an important mycotoxigenic species (2). Thus, infection of durum wheat crops with A. sacchari could pose a significant threat to North American wheat production.

A collection of 63 bread wheats (Triticum aestivum L.) and 21 durum wheats (Triticum durum Desf.) commonly grown in Portugal since 1982 were characterized for the composition of wheat storage proteins (WSP), high molecular weight glutenin subunits (HMW‐GS), low molecular weight glutenin subunits (LMW‐GS) and ω‐gliadins. The composition of HMW‐GS, LMW‐GS and &amp;‐gliadins, encoded at loci Glu‐1, Glu‐3 and Gli‐1, respectively, was revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. WSP allelic compositions of bread and durum wheat patterns were given. In the bread wheats, a total of 24, 24 and 18 patterns were observed for HMW‐GS, LMW‐GS and ω‐gliadins, respectively. Forty‐two different alleles were identified for the nine loci studied, Glu‐A1 (3), Glu‐B1 (7), Glu‐D1 (4), Glu‐A3 (5), Glu‐B1 (7), Glu‐D3 (2), Gli‐A1 (2), Gli‐B1 (8) and Gli‐D1 (4). In the case of durum wheats, 19 alleles were identified: one allele at Glu‐A1, two at Glu‐B3, Glu‐B2 and Gli‐A1, three at Glu‐B1, four at Glu‐A3 and five at Gli‐B1. For HMW‐GS, LMW‐GS and ω‐gliadins, three, six and six different patterns were revealed, respectively. This study represents the first attempt to discriminate the bread and durum wheat varieties commonly grown in Portugal by the allelic variation of storage proteins. The database is useful for varietal identification and for plant breeders who seek to devise effective programmes aimed at improving wheat quality.

Leaf rust (Puccinia triticina Eriks. & Henn.) is a major disease affecting durum wheat production. The Lr14a-resistant gene present in the durum wheat cv. Creso and its derivative cv. Colosseo is one of the best characterized leaf-rust resistance sources deployed in durum wheat breeding. Lr14a has been mapped close to the simple sequence repeat markers gwm146, gwm344 and wmc10 in the distal portion of the chromosome arm 7BL, a gene-dense region. The objectives of this study were: (1) to enrich the Lr14a region with single nucleotide polymorphisms (SNPs) and high-resolution melting (HRM)-based markers developed from conserved ortholog set (COS) genes and from sequenced Diversity Array Technology (DArT(®)) markers; (2) to further investigate the gene content and colinearity of this region with the Brachypodium and rice genomes. Ten new COS-SNP and five HRM markers were mapped within an 8.0cM interval spanning Lr14a. Two HRM markers pinpointed the locus in an interval of <1.0cM and eight COS-SNPs were mapped 2.1-4.1cM distal to Lr14a. Each marker was tested for its capacity to predict the state of Lr14a alleles (in particular, Lr14-Creso associated to resistance) in a panel of durum wheat elite germplasm including 164 accessions. Two of the most informative markers were converted into KASPar(®) markers. Single assay markers ubw14 and wPt-4038-HRM designed for agarose gel electrophoresis/KASPar(®) assays and high-resolution melting analysis, respectively, as well as the double-marker combinations ubw14/ubw18, ubw14/ubw35 and wPt-4038-HRM-ubw35 will be useful for germplasm haplotyping and for molecular-assisted breeding.

Genetic mapping in durum wheat (Triticum durum Desf.) is constrained by its large genome and allopolyploid nature. We developed a Diversity Arrays Technology (DArT) platform for durum wheat to enable efficient and cost-effective mapping and molecular breeding applications. Genomic representations from 56 durum accessions were used to assemble a DArT genotyping microarray. Microsatellite (SSR) and DArT markers were mapped on a durum wheat recombinant inbred population (176 lines). The integrated DArT-SSR map included 554 loci (162 SSRs and 392 DArT markers) and spanned 2022 cM (5 cM/marker on average). The DArT markers from durum wheat were positioned in respect to anchor SSRs and hexaploid wheat DArT markers. DArT markers compared favourably to SSRs to evaluate genetic relationships among the durum panel, with 1315 DArT polymorphisms found across the accessions. Combining DArT and SSR platforms provides an efficient and rapid method of generating linkage maps in durum wheat.

Many ecological regions of Turkey are suitable for the production of durum wheat, and therefore the yield and quality of this wheat should be improved. In this study, stability properties associated with the pasta quality of 25 durum wheat (Triticum durum Desf.) genotypes grown in 3 different locations (Tokat-Kazova, Diyarbakır, and Sivas-Ulaş) for 2 years (2005-2006, 2006-2007) were investigated. Durum wheat genotypes were composed of 12 registered varieties and 13 advanced experimental lines. Field trials were conducted in a randomized complete block design with 3 replications. Protein content, gluten index, sedimentation and specific sedimentation volumes, yellow pigment content, and lipoxygenase activity of the durum wheats were measured as major quality characteristics. The regression coefficient (b_i) and mean square of deviation from regression (S^2_d) were employed as the stability parameters. Genotypes, growing environments, and their interactions were found to be statistically significant (P < 0.01) for all investigated quality characteristics. No cultivars were determined to be simultaneously stable for all of the quality characteristics, yet some of the genotypes prevailed for certain quality characteristics. The genotypes with the same origin took part in the same group as judged by the cluster analysis. Of the advanced experimental durum wheat lines, Line - 1, Line - 7, Line - 20, and Gdem - 12, which displayed better quality characteristics than the overall means, can be used as breeding materials. Of the registered varieties, Aydın - 93, Çeşit - 1252, and Gidara were determined to be stable by both parameters in certain quality characteristics.

Relay intercropping is considered a valuable agroecological practice to increase and stabilize crop yields while ensuring the provision of several ecosystem services as well as sustainability and resilience to changing climatic conditions. However, farmers are still reluctant in the use of intercropping practices since there is a huge knowledge gap regarding the time of sowing, sowing ratio, crop stand density, and cultivar choice. In this study, we carried out a 3-year field experiment in Central Italy to assess the effect of relay intercropping on the agronomic performance and competitiveness of winter durum wheat (Triticum durum Desf. cv. Minosse) and spring lentil (Lens culinaris Medik. cv. Elsa) under a low-input management system, comparing different crop stand types (monocrop vs. intercrop) and target plant densities (350 plants m2—full dose vs. 116 plants m2—1/3 dose). The results revealed that intercropping increased grain yield compared to monocropping: significantly (p &lt; 0.0001) against both monocrops in 2021 and non-significantly against durum wheat in 2019 and 2020. Yield advantage in both intercropping systems ranged between 164 and 648%. Durum wheat competitiveness was stronger in 2019 and 2021, while lentil was the most competitive component in 2020. Intercropping favored P accumulation in durum wheat shoots. There was no difference in grain yield of both crops between the highly- and lowly-dense system in 2020 and 2021. Both intercropping strategies were as effective as mechanical hoeing in controlling weeds and proved beneficial in stabilizing lentil productivity. Further economic analysis capturing the additional costs incurred in intercropping and mechanical weeding would highlight the magnitude of profitability of these systems.

In order to investigate the germination characteristics and cardinal temperatures of Thymus transcaspicus, a laboratory experiment was conducted with two different cultivated and natural seedlots at constant temperatures including 2, 5, 10, 15, 20, 25, 30, 35, 40 and 45 °C in a completely randomized design with four replications. Two seedlots were monitored for variability in germination criteria based on three regression models namely: Five-parameters Beta (FPB), Intersected-lines (ISL) and Quadratic Polynomial (QPN) models. The effect of temperature on rate and percentage of seed germination in both seedlots was significant. For both seedlots the highest germination percentage (GP) was within the range of 10-30 °C while the highest germination rate (GR) occurred in 30 °C. Although means of GP and GR for the field seedlot were higher than the natural seedlot, variability of GP and GR in response to temperature was higher for natural seedlot. Best model fit over the entire temperature range was obtained by the FPB and ISL models for both seedlots. However, FPB model showed most suitable fitness particularly in the case of natural seedlot. Based on the regression between germination rate and temperature in both seedlots, the cardinal temperatures (Tbase, Topt and Tmax) were: (1.2-3.84), (29.1-25.8) and (45-47) °C for field seedlot and (1.0-3.3), (24.9-29) and (45-46) °C for natural seedlot, respectively.

Durum wheat (Triticum durum Desf.), among the herbaceous crops, is one of the most extensively grown in the Mediterranean area due to its fundamental role in supporting typical food productions like bread, pasta, and couscous. Among the environmental and technical aspects, nitrogen (N) fertilization is crucial to shaping plant development and that of kernels by also affecting their protein concentration. Today, new techniques for monitoring fields using uncrewed aerial vehicles (UAVs) can detect crop multispectral (MS) responses, while advanced machine learning (ML) models can enable accurate predictions. However, to date, there is still little research related to the prediction of the N nutritional status and its effects on the productivity of durum wheat grown in the Mediterranean environment through the application of these techniques. The present research aimed to monitor the MS responses of two different wheat varieties, one ancient (Timilia) and one modern (Ciclope), grown under three different N fertilization regimens (0, 60, and 120 kg N ha−1), and to estimate their quantitative and qualitative production (i.e., grain yield and protein concentration) through the Pearson’s correlations and five different ML approaches. The results showed the difficulty of obtaining good predictive results with Pearson’s correlation for both varieties of data merged together and for the Timilia variety. In contrast, for Ciclope, several vegetation indices (VIs) (i.e., CVI, GNDRE, and SRRE) performed well (r-value &gt; 0.7) in estimating both productive parameters. The implementation of ML approaches, particularly random forest (RF) regression, neural network (NN), and support vector machine (SVM), overcame the limitations of correlation in estimating the grain yield (R2 &gt; 0.6, RMSE = 0.56 t ha−1, MAE = 0.43 t ha−1) and protein (R2 &gt; 0.7, RMSE = 1.2%, MAE 0.47%) in Timilia, whereas for Ciclope, the RF approach outperformed the other predictive methods (R2 = 0.79, RMSE = 0.56 t ha−1, MAE = 0.44 t ha−1).