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Updated: Sep 8, 2025
Establishment of a Chilli Thrips (Scirtothrips dorsalis Hood) Rearing System for Virulence Screening of Entomopathogenic Fungi
Published on: July 18, 2025
Genetic diversity and marker trait association for phytophthora resistance in chilli
Tazien Bukhari1, Rashid Mehmood Rana2, Mahmood Ul Hassan1
1Department of Plant Breeding and Genetics, PMAS-Arid Agriculture University, Rawalpindi, 46300, Pakistan.
Background:
Chilli is an important commercial crop with positive returns tendency. Phytophthora root rot causes drastic damage to chilli plant. Dearth of detecting marker trait associations is a major hinderance in practicing marker assisted selection in chilli breeding.
Methods And Results:
Herein, 110 chilli accessions were assessed for 15 agronomic traits under control and disease infected conditions for two crop seasons (2018-2019). The SSR genotyping revealed high values of major allele frequency (MAF = 0.70), genetic diversity (GD = 0.39) and Polymorphic Information Content (PIC = 0.31). Principal coordinate analysis and population structure analysis showed distribution of diverse genotypes in all groups by dividing 110 genotypes in three populations and nine sub-populations. The UPGMA based Archaeopteryx tree was in concordance with population structure analysis. Linkage disequilibrium analysis evaluated that LD decays within 3-10 bp. Marker trait association (MTA) revealed the associations of 35 SSRs with 14 morphological traits. The significant MTA for marker CAeMS073 with relative leaf damage (RLD, 0.183 R2) under control and treated conditions was consistently observed in both models. The markers, CAMS173 and CAMS194 were found to be strongly associated with RLD and Disease Index (DI), respectively. The absence of MTA was detected for height of first branch.
Conclusion:
The MTAs reported in this study can facilitate marker assisted breeding for developing chilli germplasm resistant against Phytophthora capsici.
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