Variation of Medicago sativa varieties tolerance to Phoma medicaginis infection.

Abstract

Due to its very important agronomic value and nutritional quality, Medicago sativa L. is considered as the queen of fodder and the first cultivated forage crop in the world. In field conditions, M. sativa is exposed to several biotic and/or abiotic constraints that affect its quality. In this regard, research is still underway to improve M. sativa resistance to many biotic stresses and, in this context, we analyzed the responses of a core collection of 10 varieties of M. sativa to Phoma medicaginis infection. Results from ANOVA showed that most growth parameters exhibited significant differences between the studied varieties. Nevertheless, only the number of healthy leaves among infection parameters varied significantly between the varieties. The local variety Gabès2355 exhibited the highest biomass. Positive correlations were found between the measured parameters. PCA based on the traits showing significant differences among the studied lines showed that the Gabès variety formed a separate group. Cluster analysis revealed that the studied varieties are classified into three major groups. The first group is formed by Gabès2353, the second group is composed of the Californian and El Hamma varieties, and the third group is constituted of the seven remaining varieties. Gabès2355 was the most tolerant to the Pm8 strain of P. medicaginis while Magna601 variety was the most susceptible. These two varieties will be useful to analyze the physiological and genetic determinants for M. sativa tolerance to P. medicaginis infection.

Discovering new genes for alfalfa (Medicago sativa) growth and biomass resilience in combined salinity and Phoma medicaginis infection through GWAS

“…Badri et al (2023) tested the effect of P. medicaginis on the variation in agronomic traits of different Medicago species, reporting that most of the variation in the measured parameters was explained by the infection treatment. Zaidi et al (2021) demonstrated that the number of healthy leaves (recorded among the infection parameters of alfalfa genotypes) varied significantly among the genotypes infected by P. medicaginis, which is consistent with the current observations.…”

“…After 2 months of cultivation, plants at the flowering bud stage were subjected to a saline treatment of 150 mM NaCl (for 21 days) until the appearance of symptoms related to saline stress. At this stage, they were infected with the strain Pm8 of Phoma medicaginis (5*10 6 conidies µL -1 ) as described by Zaidi et al. (2021) .…”

“…After 2 months of cultivation, plants at the flowering bud stage were subjected to a saline treatment of 150 mM NaCl (for 21 days) until the appearance of symptoms related to saline stress. At this stage, they were infected with the strain Pm8 of Phoma medicaginis (5*10 6 conidies μL -1 ) as described by Zaidi et al (2021). Previous optimization studies by Badri et al (2021) and Jabri et al (2021) on alfalfa grown under a range of salt concentrations (NaCl) have revealed that 150 mM NaCl is the most appropriate for analyzing the behavior of accessions of this species under this constraint.…”

Biodiversity of the Genus Medicago from Africa

“…Furthermore, analysis of the responses of 10 varieties of M. sativa to infection by P. medicaginis revealed that the studied varieties are classified into three large groups [32]. The first group is formed by Gabès2353, the second group is constituted of the Californian and El Hamma varieties, and the third group is composed of the remaining seven varieties.…”

“…Finally, Medicago species showed a high level of variability in responses to abiotic and biotic stresses. Diversity within and among populations has been noted for water deficit [24], salinity [25][26][27], nutritional deficiencies [28], and resistance to pathogens [29][30][31][32].…”