Exploring the phenotypic diversity of a Moroccan barley collection conserved ex-situ in the INRA Genebank

Cette étude a pour objectif d'analyser l'étendue de la diversité phénotypique d’une collection constituée de 200 populations locales marocaines d’orge, conservée ex-situ dans la banque de gènes de l’INRA, sur la base de 12 caractères agro-morphologiques en utilisant les indices de diversité et les analyses multi variées. L’indice de Shannon-Weaver (H’) a montré une forte variation pour l’ensemble des caractères étudiés. Le H’ moyen obtenu pour l’ensemble de la collection est de 0,63. Par ailleurs, l’analyse en composantes multiples (ACM) ont permis de structurer la diversité observée en deux grands groupes selon l’origine et la proximité géographique de chaque accession. Le premier groupe est constitué principalement des accessions d’orge issues des montagnes de l’Atlas et du Rif et l’autre groupe est composé des accessions originaires des autres régions agroécologiques du Maroc. Cette diversité pourrait être valorisée pour le développement de variétés à usages multiples. Mots clés : Diversité phénotypique, populations locales, conservation ex-situ, valorisation, banque de gènes, orge.This study was conducted to analyze the extent of phenotypic diversity of a collection consisting of 200 Moroccan barley landraces, conserved ex-situ in the INRA Genebank, on the basis of 12 morphological characters using diversity indices and multivariate analysis. The Shannon-Weaver index (H’) showed a strong variation for all the studied traits. The H’ mean for the entire collection was 0.63. In addition, the multiple component analysis (MCA) structured the observed diversity into two large groups according to the origin and geographic proximity of each accession. The first group consists mainly of barley accessions from the Atlas and Rif mountains and the other group is composed of accessions from other agro-ecological regions of Morocco. This diversity could be exploited for the development of varieties with multiple uses. Keywords: Phenotypic diversity, landraces, ex-situ conservation, valorization, genebank, barley

Assessment of the Glutenin Subunits Diversity in a Durum Wheat (T. turgidum ssp. durum) Collection from Morocco

Landraces and old wheat cultivars display great genetic variation and constitute a valuable resource for the improvement of modern varieties, especially in terms of quality. Gluten quality is one of the major determinants of wheat quality, and it is greatly influenced by variation in the high molecular weight and low molecular weight glutenin subunits (HMW-GS and LMW-GS). Identification of novel allelic variants for either of the two groups of the gluten-forming proteins could greatly assist in the improvement of wheat gluten quality. In the present study, the allelic composition of the HMW- and LMW-GS of ninety-five durum wheat accessions was evaluated. These accessions included Moroccan cultivars and landraces and North American cultivars and were all conserved in the National Gene Bank from Morocco. In total, 20 cataloged alleles and 12 novel alleles were detected. For the HMW-GS, two alleles were found at the Glu-A1 locus, and seven different allelic variants were identified at the Glu-B1 locus. Among them, two alleles were new (alleles Glu-B1cp and co). Additionally, two of the analyzed accessions exhibited the Glu-D1d allele, suggesting the presence of the Glu-D1 locus introgression. For the LWM-GS, eight, ten and two alleles were identified at the Glu-A3, Glu-B3 and Glu-B2 loci, respectively. Among them, two new allelic variants were identified at the Glu-A3 locus, and seven new allelic variants were identified at the Glu-B3 locus. Overall, the Moroccan landraces exhibited a greater genetic diversity and a greater number of glutenin alleles compared to the Moroccan and North American durum wheat cultivars. The novel germplasm and glutenin alleles detected in this study could contribute to the improvement of durum wheat quality and the expansion of modern durum wheat genetic diversity

Agro-morphological variability in durum wheat landraces of Morocco

Abstract The knowledge about the extent of variability, the distribution and the relationship between descriptors within local germplasm collection are a high value for the improvement and the efficient genetic diversity maintenance and utilization of plant species. The objective of this study was to evaluate the agro-morphological variability in a set of Moroccan durum wheat germplasm collection maintained in the National Gene Bank of Morocco (INRA, Settat). 467 durum wheat (Triticum turgidum L. var. durum) accessions comprising 444 landraces and 23 improved varieties were planted under field condition and their agro-morphological characters such as days to emergence, days to tillering, days to booting, days to head emergence, days to flowering, days to physiological maturity, plant height, thousands kernel weight, spike shape, and spike density were recorded. Univariate and multivariate analysis of data indicated that thousands kernel weight and plant height presented the highest coefficient of variation with 15.72% and 15.15% respectively. The two-dimensional principal coordinates analysis (2D PCOA) explained 52% of the total variance in the collection and separated the accessions into three main groups, namely, the early maturing and shorter (81 accessions), the moderately late and taller (154 accessions), and the late maturing and taller (232 accessions). The frequency distribution of spike characters showed the prevalence of the pyramidal and the dense spike with 54% and 42% respectively. The results of this study will support efforts of conservation and utilization of landraces in durum wheat breeding programmes

Short-term residual effects of occasional tillage on crop performance, soil water, and water-use efficiency in a 10-year no-till system under a dry Mediterranean climate

Conservation Agriculture is a farming system based on no mechanical soil disturbance, permanent soil cover, and crop diversification. A study was carried out in an on-farm field trial set up in Meknes (Morocco) under a long-term no-till (NT) system to evaluate the residual effect of one-time occasional tillage (OT) on crop performance, soil water, and water-use efficiency (WUE) one and two years after OT implementation. Shallow and deep options of OT were compared with common NT practices (with crop residue retention and with crop residue removal) for two consecutive seasons of 2021–2022 (year 1) and 2022–2023 (year 2). The four tillage practices were implemented in November 2020. Three crops were studied each year: durum wheat (Triticum durum), faba bean (Vicia faba minor), and chickpea (Cicer arietinum) all grown under NT in both the years and arranged in four crop rotations. Our findings show that grain yield of wheat and chickpea was negatively affected by OT for all years considered. In wheat, there was a grain yield loss of 18 and 20% for shallow and deep OT, respectively compared to NT with crop residue retention. In chickpea, the grain yield loss was as high as 47 and 49% for shallow and deep OT, respectively. Average soil water storage measured at 0–60 cm at sowing was also lower in deep OT (133 mm) compared to NT with crop residue retention (151 mm) for all years and rotations considered. Yet, in wheat year 1, deep OT slightly improved soil water content at 30 cm depth compared to NT treatments. The comparison of WUE between treatments showed that, under NT with crop residue retention, the crops produced more grain and aboveground biomass per mm of water. Wheat/faba bean rotation had a greater grain yield and WUE (all years considered) and overall greater soil water content (year 1), compared to the wheat/chickpea rotation. The results suggest that the effects of OT on crop performance and water productivity in the short term can be adverse. On the other hand, grain yield of wheat can be improved by a judicious choice of legume to be used as a preceding crop

Diversité phénotypique et structure des populations de lentilles conservées à la banque de gènes de l'INRA

The phenotypic diversity of two hundred accessions of lentils, originated from different countries and conserved ex-situ at the INRA Genebank, was studied using 12 morphological traits. The accessions were grouped into five geographic regions, and their frequencies were examined. The twelve morphological traits showed significant variation among geographical origins of the lentil accessions. Moreover, the Shannon-Weaver index (H') showed a strong variation for all the studied traits. The average H' for the entire collection was 0.6. Furthermore, a multiple correspondence analysis (MCA) was conducted and structured the observed diversity into three groups according to the origin and geographic proximity of each accession. These results will guide future collection missions, ensuring better conservation and utilization of the collection in breeding and germplasm enhancement programs, and the promotion of genetic resources in Morocco.La diversité phénotypique de 200 accessions de lentilles, originaires de différents pays et conservées ex-situ dans la Banque de gènes de l'INRA, a été étudiée en utilisant 12 traits morphologiques. Les accessions ont été regroupées en cinq régions géographiques, et leurs fréquences ont été examinées. Les traits morphologiques ont montré une variation significative selon les origines géographiques des accessions de lentille. De plus, l'indice de Shannon-Weaver (H') a montré une forte variation pour tous les traits étudiés. La valeur moyenne de H' pour l'ensemble de la collection était de 0,6. Par ailleurs, une analyse de correspondance multiple (ACM) a été réalisée et a structuré la diversité observée en trois groupes en fonction de l'origine et de la proximité géographique de chaque accession. Ces résultats guideront les futures missions de collecte afin d’assurer une meilleure conservation et utilisation de la collection dans les programmes d'amélioration génétique, d’enrichissement du germoplasme et de promotion des ressources génétiques au Maroc

Diversité phénotypique et structure des populations de lentilles conservées à la banque de gènes de l'INRA

La diversité phénotypique de 200 accessions de lentilles, originaires de différents pays et conservées ex-situ dans la Banque de gènes de l'INRA, a été étudiée en utilisant 12 traits morphologiques. Les accessions ont été regroupées en cinq régions géographiques, et leurs fréquences ont été examinées. Les traits morphologiques ont montré une variation significative selon les origines géographiques des accessions de lentille. De plus, l'indice de Shannon-Weaver (H') a montré une forte variation pour tous les traits étudiés. La valeur moyenne de H' pour l'ensemble de la collection était de 0,6. Par ailleurs, une analyse de correspondance multiple (ACM) a été réalisée et a structuré la diversité observée en trois groupes en fonction de l'origine et de la proximité géographique de chaque accession. Ces résultats guideront les futures missions de collecte afin d’assurer une meilleure conservation et utilisation de la collection dans les programmes d'amélioration génétique, d’enrichissement du germoplasme et de promotion des ressources génétiques au Maroc

Genetic diversity and structure of a barley collection predominatly from North African region

The cultivated barley ranks fourth cereal crop in the world. The demand for higher-yielding, nutritious, and better-adapted crop varieties has increased the need to exploit genebanks diversity. Thus, assessing the genetic diversity of barley is essential to determine the genetic relationship between lines and deploy novel alleles in breeding programs. Here, we used 14 polymorphic Simple Sequence Repeat (SSR) markers to assess genetic diversity, genetic relationship, and population structure of 113 barley lines originated from 14 countries, and the majority from Africa. The average alleles per locus of 5.36, Polymorphism Information Content (PIC) of 0.57, and genetic diversity of 0.61 indicate a high degree of genetic variation in this collection. The Analysis of Molecular Variance AMOVA showed genetic variation within countries to be higher (74%) than among countries (26%). The STRUCTURE analysis was consistent with neighbor-joining clustering and principal components analysis, which identified three main subpopulations clustered primarily according to their geographic origin. Growing environments, migration between and within countries might have caused a considerable genetic diversity observed in the North African barley germplasm. The results of this study contribute to the conservation and utilization of these barley germplasm

Distribution of alleles related to grain weight and quality in Moroccan and North American wheat landraces and cultivars

Combining improved grain yield and end-product quality in durum wheat has become an essential priority for Moroccan breeding programs due to their significant effect on the country's agricultural economy and social system. Landraces and cultivars of distinct germplasm pools constitute an untapped source of genetic variation for durum wheat improvement. To this end, a mixture of genotypes consisting of 35 landraces (LAN), 20 North American cultivars (NAC) and 10 Moroccan cultivars (MC), was evaluated using grain weight and grain size parameters, quality characteristics, and 21 functional molecular markers. Significant genetic variability was revealed between the genotypes. According to observed means across traits, MC showed the best grain characteristics, followed by NAC, and LAN. However, NAC showed overall better physiochemical characteristics. Genetic diversity applying quality trait-based markers increased from LAN to advanced cultivars. Favorable alleles Lpx-B1.1b (Lpx-B1.1), Hap-4A-T (TaCwi-4A), TaGS5-A1b (TaGS5-A1) were predominant in NAC. Unfavorable alleles, namely Psy1-B1a (Psy1-B1), Psy-B1a or b (Psy-B1), Lox-B1a (Lox-B1), Hap- 4A-C (TaCwi-4A), TaGS5-A1a (TaGS5-A1), TaTGW6-b (TGW6-4A), Hap-L (TaSus2), and TaTGW6-A1b (TGW6), were most frequent or even omniprevalent in all genotypes. This work can up open new avenues for the development of new varieties allying yield and grain quality by introducing suitable genotypes and favorable alleles into Moroccan national breeding programs

A Genome-Wide Association Study Identifying Single-Nucleotide Polymorphisms for Iron and Zinc Biofortification in a Worldwide Barley Collection

Micronutrient deficiency affects half of the world’s population, mostly in developing countries. Severe health issues such as anemia and inadequate growth in children below five years of age and pregnant women have been linked to mineral deficiencies (mostly zinc and iron). Improving the mineral content in staple crops, also known as mineral biofortification, remains the best approach to address mineral malnutrition. Barley is a staple crop in some parts of the world and is a healthy choice since it contains β-glucan, a high dietary protein. Barley mineral biofortification, especially with zinc and iron, can be beneficial since barley easily adapts to marginalized areas and requires less input than other frequently consumed cereals. In this study, we analyzed zinc and iron content in 496 barley samples. The samples were genotyped with an Illumina 50 K SNP chip. Genome-wide association studies (GWAS) identified 62 SNPs and 68 SNPs (p p < 0.005), there were 12 SNPs (single-nucleotide polymorphism) associated with Zn and 6 for iron. SNP annotations revealed proteins involved in membrane transport, Zn and Fe binding, linked to nutrient remobilization in grains. These results can be used to develop biofortified barley via marker-assisted selection (MAS), which could alleviate mineral malnutrition

Genetic diversity reduction in improved durum wheat cultivars of Morocco as revealed by microsatellite markers

ABSTRACT It has been argued that genetic diversity in crop varieties has been on the decline in recent times due to plant breeding. This can have serious consequences for both the genetic vulnerability of crops and their plasticity when responding to changes in production environments. It is, therefore, vital for plant breeding programs to maintain sufficient diversity in the cultivars deployed for multi-period cultivation. In this study, to understand the temporal genetic diversity in durum wheat, 21 improved durum wheat cultivars released in Morocco, since 1956 and five exotic cultivars currently used in crossing programs were analyzed using 13 microsatellite markers. The analysis revealed a total of 44 alleles and average genetic diversity of 0.485 with genetic distances ranging from 0.077 to 0.846 at 13 microsatellite loci in Moroccan durum wheat cultivars. All the durum cultivars of Morocco could be distinguished using the 13 microsatellite markers. The total number of alleles and unique alleles were highest in cultivars developed before 1990, decreasing in cultivars developed during the 1990s and 2000s, indicating that recent durum breeding efforts have reduced allelic richness in recent cultivars. Thus, deployment of exotic durum wheat lines in breeding programs could enhance genetic diversity in durum wheat cultivars