Genetic Diversity of Grapevine Virus Explored in Algerian ‍Vineyards

ALGIERS (AP) —‍ A recent study has​ shed ‌light‍ on teh genetic ​variability of grapevine Rupestris Stem Pitting-Associated‌ Virus (GRSPaV) within Algerian⁤ vineyards. ⁢GRSPaV, a widespread virus affecting grapevines ⁤across ⁢numerous‍ wine-producing⁣ regions, exhibits important genetic diversity, ​prompting researchers to investigate ​its prevalence and variations within Algeria.

The research, published in Phytopathologia Mediterranea The International Journal of the Mediterranean Phytopathological ‌Union, focused on analyzing the complete capsid protein (CP) gene sequences of GRSPaV isolates collected ‍from Algerian vineyards. The analysis ⁢revealed sequence similarities ranging from 76% to 99% among the isolates.

Key Findings on GRSPaV ⁤Genetic Structure

High-speed sequencing and bioinformatic analyses⁤ were used ‌to determine the complete coding gene sequence (8,646 nt) of the Algerian GRSPaV isolate, alg99.⁣ The study categorized the Algerian ⁢GRSPaV isolates into four ​distinct groups,⁣ with the majority of sequences falling into groups III and IV.

According to ‌the study, GRSPaV is the predominant grapevine virus‌ reported in Algeria, with ⁤an infection rate⁤ of 57.92%, as noted by Bachir et⁤ al. in 2019.

Global Context‌ of ​GRSPaV Prevalence

The prevalence of⁤ GRSPaV in Algerian vineyards aligns with ⁣its widespread presence in many wine-producing​ countries, as⁤ documented in studies by Martelli (1993), Digiaro et al. (1999), Meng⁢ and Gonsalves (2007), Fiore⁣ et al. ⁤(2016), Selmi⁣ et al. (2017), and Morelli ​et al. (2011). The ‌virus’s high incidence in vineyards is primarily attributed to its dissemination through the propagation of infected vine material.

While the natural transmission methods of GRSPaV remain‌ largely⁣ undescribed, the virus is frequently reported in ⁣both ⁤cultivated and wild grapevines throughout⁤ the Mediterranean basin,‍ according to Pacifico et al.⁣ (2016) and Selmi et⁤ al.(2020).

Detailed ‌Genetic Analysis of‌ Algerian⁢ GRSPaV Strains

Examination of nucleotide relations between grspav ⁢isolates‌ for CP genes showed​ that similarities​ ranged from ⁤76 to 99 %.⁤ The Algerian strain of GRSPAV-N18 has shown the greatest similarity (99 %) with the CG1 strain.

The analysis revealed that certain strains are‍ closely related. Such as, the DZGRSPAV-N09, DZ-GRSPAVN10, DZ-GRSPAV-N14 and DZ-GRSPAV-N15⁢ strains presented a great nucleotide similarity but were ⁢different from the strains of GRSPAV-N11, DZGRSPAV-N13​ and⁤ DZ-GRSPAVN17, which had a⁢ similarity of 92 to 97 %. The two strains DZGRSPAV-N16​ and DZ-GRSPAVN18 had a low similarity between them and with the other Algerian‍ strains.

Comparative ‌Genetic​ Variability

These findings⁤ are consistent with other research. Selmi et al. (2020) reported significant‍ variability in ‌the CP gene ⁤of ⁣Tunisian strains, with nucleotide similarity⁣ ranging from 71% to 100%. Similarly, hu et al. ⁤(2015) observed considerable variability in⁣ Chinese strains, with nucleotide similarity‍ ranging ‍from 82% to​ 98%. Alabi et al. (2010)​ also documented significant⁢ genetic variability in⁣ GRSPaV CP and RDRP genes in the United States, with nucleotide similarities ranging‌ from ​79% to 100%.

A phylogenetic tree, constructed‍ using sequenced samples ​and strains from Genbank, confirmed the results of nucleotide⁢ comparisons of Algerian strains and identified nine distinct ⁢groups.‍ the Algerian sequences of GRSPaV were grouped into four categories (I, II, III, and IV), with the ‌majority (eight) falling into groups III ⁤and⁤ IV.

Phylogenetic analysis by Selmi et ⁢al. (2020) showed that Tunisian GRSPaV sequences also clustered into four main​ groups (I, II, ‍III, and IV), with group III primarily ​containing strains from commercial vines. However, Selmi⁣ et al.(2020)⁣ identified two new ⁤groups composed of ⁤Tunisian strains from spontaneous and cultivated Aboriginal vines, suggesting that confined natural habitats could serve as‌ sources of viral diversity.

Distribution of GRSPaV Variants

Several studies ‌have examined the distribution of grspav ⁢variants.Meng et al.(2006) ⁣reported ‌that phylogenetic analyses ⁣based ‍on the CP gene for table ⁣and ⁢wine grapes in the⁢ United States,Canada,and Italy ⁢were distributed in groups I,II,III,and IV. They found⁤ that 68% of GRSPaV⁤ variants belonged to groups ⁤I and II, ⁤24%⁢ to group ⁤III, and only 8% to group ⁤IV. Hooker (2017) also‍ reported that more than 50% of⁣ variants in ⁣the united States clustered in group IV, and 23%⁣ in⁤ group I.

The⁢ variations in ⁤viral strains ⁣might potentially be attributed​ to‌ the​ widespread marketing of⁣ Vitis plant material infected with these variants.

Future Research directions

Further research on the infection rates of⁤ indigenous and wild vine‌ varieties⁤ is recommended to enhance‌ understanding of the distribution‌ and evolution of​ GRSPaV ‌in different regions of algeria.