Genetic variability in agro-morphological and quality traits of Mediterranean durum wheat landraces

Durum wheat landraces are still cultivated to take advantage of their excellent grain and straw quality, adaptation to abiotic stresses, and extremely wide variety of uses. The safeguarding and rehabilitation of genetic inheritance requires genetic characterization and evaluation. In this study, forty durum wheat landraces originating from Mediterranean countries were evaluated according to agro-morphological and technological properties. We show that the germplasm was highly variable. The mean yellow pigment and protein content was higher in landraces (15.58%; 7.32 ppm) than in the Moroccan cultivars used as controls (14.6%; 5.48 ppm). In addition, principal component analysis identified five groups showing variable agronomic and qualitative characteristics that might be useful in the rational design of breeding programs

Development of an efficient regeneration system for bombarded calli from immature embryos of Moroccan durum wheat varieties

ArticleOne of the biggest obstacles limiting genetic transformation of durum wheat is the lack of an efficient regeneration system for bombarded tissues. Our study aims to optimize culture conditions for regenerating bombarded calli from immature embryos of four durum wheat varieties ‘Amria’, ‘Chaoui’, ‘Isly’ and ‘Marouane’, through comparing the effects of phytohormones (IAA, zeatin and their interaction) and nitrogen amount and sources on callus induction and plant regeneration. Both tested induction media induced approximately the same rate of induced calli for all the tested varieties. However, the interaction of the induction and the regeneration media showed a highly significant effect on plantlet regeneration for all tested varieties. After bombardment, IM1/RM2 combination proved to be the favourable medium with up to 200% and 120% plantlets regenerated for ‘Chaoui’ and ‘Isly’ varieties respectively. Encouraging results obtained in this study will help to promote the research in genetic transformation and its improvement

Vegetative Propagation of Argania spinosa (L.) Skeels Cuttings: Effects of Nutrient Solution

The effects of the mineral composition of nutrient solution (Hoagland and Arnon (HA), Quoirin and Lepoivre (QL), Murashige and Skoog (MS), and Woody Plant Medium (WPM)), cutting type (softwood, semi-hardwood and hardwood) and cutting position (basal, medial, and apical) on sprouting and rooting performance of Argania spinosa cuttings were investigated. According to the results, the nutrient solution, cutting type and cutting position had an effect on the sprouting and adventitious rooting ability of A. spinosa cuttings. The leafy semi-hardwood cuttings taking from the basal positions and irrigated with Hoagland solution performed best and produced the highest number of roots (44.63), root length (28.86 cm), and had the highest rooting and survival percentage (63.81% and 96.09%, respectively). The nutrient solution applications caused a notable increase in sprouting and rooting potential of the argan tree. The highest values were recorded for HA and QL, while the MS and WPM gave the poorest result and the greatest mortality rate of cuttings. The cuttings type had also a pronounced effect on vegetative propagation of A. spinosa. The leafy semi-hardwood cuttings performed better than the leafy softwood cuttings, whereas leafless hardwood cuttings were completely unable to sprout and root even when treated with nutrient solutions. Thus, vegetative propagation of A. spinosa can best be achieved using basal leafy semi-hardwood cuttings irrigated with Hoagland nutrient solution

Genetic gain of grain yield and quality in bread wheat cultivars representing 40 years of breeding in Morocco

Background. Knowledge about the genetic gain for fundamental traits over time is essential for a critical assessment and improvement of breeding programs, especially regarding staple crops like bread wheat.Materials and methods. To estimate the genetic gain in bread wheat breeding in Morocco, grain yield (GY) and grain protein content (GPC) data were collected from 12 multi-environment field trials for 20 bread wheat cultivars released between 1980 and 2022.Results and discussion. Analysis of variance highlighted a high significant variability between environments (E), cultivars (G), and a significant G × E interaction (P < 0.001). Based on stability analysis, the modern cultivars released during the two last decades (2002–2012 and 2013–2022) showed the highest performances and wider stability than old ones, especially in low-yielding environments. Genetic gain (GG) for GY was 21.4 kg ha−1 yr−1 (0.75% yr–1) over 4 decades of breeding. This progress was declining when advancing in decades and ranged from 11% (from 1980–1990 to 1991–2001) to less than 7% (from 2002–2012 to 2013–2022). The GG in low and intermediate yielding environments were the most important (17.34% and 6.88% yr–1 respectively), while GG was nonsignificant in high-yielding environments (4.62% yr–1). Within the same period, GPC showed a nonsignificant negative trend of –0.007% (–0.002% yr–1), while derivative parameters from GY and GPC indicated high positive genetic progress. More efforts should be deployed to implement a good balance between yield performance and quality in the new released cultivars despite the negative correlation between these two traits (r = –0.36; P < 0.001).Conclusion. Adopting advanced technologies, like genomic selection, adequate agronomic practices, and more efficient selection criteria are essential steps to further increase simultaneously grain yield and quality traits

Genotype x Environment interaction for quality traits in durum wheat cultivars adapted to different environments

The quality traits of durum wheat are important for the utilization by the industries. These traits may be influenced by genotype and interaction of genotype and environment (GxE). To evaluate the effects of genotype, environment and genotype x environment interaction on quality traits such as vitreousness, SDS sedimentation test, yellow pigment index, protein content and test weight, twelve Moroccan durum wheat cultivars representing a range of agronomic adaptation were tested in five locations representing a range of environments in three growing seasons. The results indicated significant effects of genotype, environment and GxE for all the quality traits. The extent of these effects differed; for SDSsedimentation volumes, yellow pigment and test weight, the component of variation due to genotype was larger than due to the environment, indicating the greater influence of genotypes on these traits. However, for vitreousness and protein content, the effect of environment was higher than the effect due to genotypes. Thus, these traits are controlled greatly by environmental effects than genetics. The variation due to GxE was higher than that of genotype for vitreousness and test weight, indicating high GxE interaction effect and less genotypic stability for these traits. For protein content, where the environmental effect was greater than that of genotype and GxE effect, multiple environmental trials are necessary in order to determine protein content of a cultivar. For other traits,  preliminary evaluations can be done in one environment and good performing ones can be selected for multiple environmental trials

Etude des dégâts qualitatifs et quantitatifs dus aux Bruches sur les légumineuses au Maroc

Les pertes qualitatives et quantitatives des légumineuses en post-récoltes demeurent un important souci des agriculteurs au Maroc. Les ravageurs de stockage sont l’un des facteurs les plus destructifs des stocks de légumineuses. Pour ce fait, le présent travail porte sur l’identification des différentes espèces d’insectes attaquant les légumineuses stockées au Maroc, et l’évaluation de leurs effets nuisibles sur les pertes en qualité, quantité et faculté germinative des grains. Les résultats mettent en évidence la dominance des coléoptères de la famille Bruchidae, qui attaquent plus de la moitié des quantités stockées surtout pour les cultures de fève et féverole. Les pertes pondérales et le pouvoir germinatif ont aussi été  étudiés. Les résultats ont montré une perte en poids des grains bruchés pouvant aller jusqu’à 34%. Le pouvoir germinatif a été négativement affecté; il a oscillé entre 75 et 85% selon le nombre d’opercule par grain.    

Domestication of <i>Avena magna</i> Murphy et Terrell: a wild tetraploid oat species endemic of Morocco

Avena magna Murphy et Terrell (2n = 4x = 28), a tetraploid oat species endemic of Morocco, has a high groat protein content (more than 20%), good resistance to diseases and good adaptability to the Mediterranean edaphic and climate conditions. Moreover, this taxon is morphologically similar to the hexaploid oat species A. sativa and promising for interspecific crosses with A. sativa in order to transfer the domestication syndrome into it. Four hybridization cycles employing four accessions of A. magna and five Moroccan hexaploid oat cultivars of A. sativa were accomplished to domesticate A. magna. Morphological characterization and cytogenetic analysis of derivative hybrid seeds were made to determine their ploidy level and select the seeds with 2n = 28. The overall combinations yielded 81 hybrid plants with 2n varying from 28 to 29, with 58% having 2n = 28, and pollen fertility over 85%. However, 27 hybrids yielded a seed set ranging from 20 to 80%. Selected hybrid plants were subjected to pedigree selection in the field until they reached the 8th generation and assessed for agronomic performance. Three domesticated lines of tetraploid oat A. magna were selected for their good disease resistance. Analysis of groat protein content in the selected hybrids using the Kjeldahl method showed that it was 2 to 3% higher than in their parents

Détermination de la diversité génétique d’une population de Septoria tritici sur blé tendre via une caractérisation culturale et pathogénique

The study of the genetic diversity of a population of Septoria tritici (Rob. ex Desm.) on bread wheat was carried out by morphologic and pathogenic characterization of isolates secured from the major wheat growing areas in Morocco. Morphologic characterization of 38 isolates showed a very marked difference between theses isolates and between/within regions. Indeed, the fungus presented 2 forms, aspect of yeast and aspect of stromatic pads. Concerning the color, 6 colors were noted: pink, orange, white, green olives, brown and black. We underlined the predominance (77 %) of the pink, orange and white color. Also, the classification of the 26 isolates studied on the basis of percentage of the leaf area necrosed with detached leaves technique gave resulting in three groups (Avirulent- Moderately virulent- Virulent). Moreover, the hierarchical classification of 14 isolates gave place to 9 pathotypes. Our results suggested that there were significant differences within isolates indicating a high genetic diversity of the pathogen in Morocco.L’étude de la diversité génétique d’une population de Septoria tritici (Rob. ex Desm.) sur blé tendre a été réalisée par la caractérisation culturale et pathogénique d’isolats collectés dans différentes régions céréalières du Maroc. La caractérisation culturale de 38 isolats in vitro a montré une différence très marquée entre les isolats étudiés et entre/intra régions. En effet, le champignon a présenté 2 formes, l’aspect de levure et l’aspect de bourrelets stromatiques. Concernant la couleur: 6 couleurs ont été notées. Elle varie entre rose, orange, blanche, vert olivâtre, marron, et noir. On a noté la dominance de la couleur rose, orange et blanche avec 77% du total des cultures. Aussi, la classification des 26 isolats étudiés sur la base du pourcentage de la surface foliaire nécrosée moyennant la technique des feuilles détachées a donné lieu à trois groupes (Avirulent- Moyennement virulent- Virulent). De plus, la classification hiérarchique de 14 isolats a donné lieu à 9 pathotypes. Cette différence nette entre les isolats montre qu’il y’a une grande diversité au sein de cette population

Sélection de nouvelles lignées de blé tendre hautement productives et résistantes à la cécidomyie, Mayetiola destructor (Say), au Maroc

Le blé (Triticum sp.) constitue l’alimentation de base de la population Marocaine. Toutefois, cette culture est attaquée par plusieurs maladies et ravageurs, dont la mouche de Hesse. Cet insecte est le ravageur le plus redoutable du blé, causant des pertes annuelles en rendement de plus de 30%. Dans le but de sélectionner un germoplasme qui combine la résistance à la cécidomyie, Mayetiola destructor (Say), et un haut potentiel de rendement, une pépinière de blé tendre HF_SBWYT_MOR_ON de 160 lignées provenant de l’ICARDA (International Center for Agricultural Research in the Dry Areas) a été évaluée pour la résistance à la cécidomyie de blé et pour le potentiel de rendement sous serre, et dans quatre environnements (sites) du Maroc: Chaouia, Abda, Doukkala et Tadla, représentés par les domaines expérimentaux de Sidi El Aidi, Jemaa Shaim, Khemis Zemamra et Deroua. L'analyse de la variance a montré des effets hautement significatifs (P<0,0001) des paramètres site, génotype et l’interaction site x génotype, pour les tests de résistance à la cécidomyie ou de rendement grain. L’évaluation sous serre a révéléque 87,5% des lignées de la pépinière sont résistantes, 9,4 % hétérogènes et 3,1 sensibles. Les lignées sont dérivées de parents résistants et expriment l’antibiosis comme mécanisme de résistance. Les meilleurs rendements en grain ont été obtenus dans la station expérimentale de Deroua conduite sous régime irrigué : 23,7 à 86 qx/ha dépassant largement la moyenne nationale (18 qx/ha). Les plus faibles rendements ont été obtenus à Khemis Zemamra: 7,7 à 41,3 qx/ha.

Agrobacterium-mediated transformation of mature embryo tissues of bread wheat (Triticum aestivum L.) genotypes

Although significant progress has been made on Agrobacterium-mediated wheat transformation, current methodologies using immature embryos as recipient tissues are labor intensive, time consuming and expensive. The use of mature embryos as explants is increasingly being recognized as an optimal method for developing regenerable cell lines during wheat transformation. Therefore, we have developed an Agrobacterium-based transformation protocol using mature embryos while adjusting several factors that influence genetic transformation efficiency. In this study, we focussed on acetosyringone concentrations, genotypes and different types of mature embryos (intact or longitudinally halved-embryos or fragmented into four latitudinal pieces) used as a source of explants for the genetic transformation. A. tumefaciens strain EHA101 harboring the plasmid vector pTF101.1 carrying the barley HVA1 gene and bar-selectable marker gene were used. Mature intact-embryos and longitudinally halved-embryos yielded the highest number of putative transgenic plantlets on the selection medium. However, no plantlets were obtained from latitudinal fragmented mature embryos. ‘Amal’ and ‘Rajae’ genotypes regenerated the highest number of putative transgenic plants and 200 μM acetosyringone was found to be the optimal concentration for their transformation. A total of 47 transgenic plants were selected with 11 plantlets showing resistance to leaf painting. Molecular analysis revealed that 1% and 0.66% of T0 regenerated plantlets were successfully transformed and carried the HVA1 gene for the ‘Amal’ and ‘Rajae’ genotypes, respectively. Additional analysis shows the transgene is stably inherited in the T1 generation. Based on the results, we conclude that among the influencing factors tested, genotypes, mature embryo explant types and acetosyringone concentration contribute significantly to the success of bread wheat transformation