Molecular characterization of Indian pathotypes of Puccinia striiformis f. sp. tritici and multigene phylogenetic analysis to establish inter- and intraspecific relationships

Abstract

Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is one of the most devastating diseases of wheat (Triticum spp.) worldwide. Indian isolates were characterised based on their phenotypic reaction on differential hosts carrying different Yr genes. Based on virulence/avirulence structure, isolates were characterised into ten different pathotypes viz. 70S0-2, 67S64, 70S4, 66S0, 70S64, 66S64-1, 38S102, 47S102, 46S119, and 78S84. These Indian pathotypes of P. striiformis f. sp. tritici and 38 pathotypes of other rust species (P. graminis tritici and P. triticina) were used in this study to analyze their molecular phylogenetic relationship. The nucleotides of rDNA-ITS, partial β-tubulin and ketopantoate reductase genes of all the pathotypes were sequenced directly after PCR. Based on sequence data of rDNA-ITS and β-tubulin, three phylogenetic groups corresponding to three different species of Puccinia were obtained. Asian isolates formed a distinct evolutionary lineage than from those derived from USA. The sequence similarity of Indian pathotypes with other Asian (China and Iran) isolates indicated the same origin of pathotypes. The results will allow rapid identification of Indian P.striiformis f. sp. tritici pathotypes causing stripe rust in wheat, assist in making predictions regarding potential rust pathotypes, and identifying sources of resistance to the disease in advance.

Spatial and Temporal Genetic Diversity and Population Structure of Hemileia vastatrix from Peruvian Coffee Plantations

“…Hence, the appearance of new H. vastatrix races capable of overcoming the resistance of new coffee cultivars in the field is likely. Studies carried out in other rusts showed a correlation between virulence phenotypes and the genetic differentiation assessed by simple sequence repeat markers ( Kolmer and Ordoñez, 2007 ); likewise, Aggarwal et al (2018) highlighted the importance of rDNA-ITS markers to differentiate Indian pathotypes from Puccinia striiformis f. sp. tritici.…”

Application of Genomics Tools in Wheat Breeding to Attain Durable Rust Resistance

“…Restriction on the cultivation of a mega wheat variety of this region namely PBW343 was imposed due to acquired virulence of Yr9 during 2008-09. The disease pressure was recorded up to 80%, which necessitated the cultivation of stripe rust-resistant wheat varieties (Aggarwal et al, 2018;Bhardwaj et al, 2019).…”

Phylogenetic analysis shows that New Zealand isolates of Neonectria ditissima are similar to European isolates

“…Although sequencing the β-tubulin and ITS gene regions was able to show several clades for Colletotrichum truncatum infecting Capsicum (Rampersad et al 2016), these may be related to Trinidad being the origin, and showing greater genetic diversity than the sub-populations exported with Capsicum over the past 189-500 years. Other studies showing separate clades by sequencing these gene regions considered separation events of thousands of years (Banke et al 2004;Aggarwal et al 2018;Maya et al 2020;Andrew et al 2021).…”