Marker- trait association analysis and population structure in core collection of Henna (Lawsonia inermis L.) germplasm

Abstract Context: Henna (Lawsonia inermis L.,) was recognized as an important medicinal plant, its therapeutic potentials, beneficial impact on health (such as antioxidant, anti-inflammatory and antimicrobial effects (and cosmetic. Aims: This study was done to determine relationships among marker loci with important traits in henna and define the most suitable population genetic structure. Methods: Association analysis was performed between 8 traits to 106 polymorphic loci generated by 9 ISSR primers in 140 ecotypes of Henna. The population structure analysis indicated three main subpopulations with significant genetic differences defined by AMOVA (analysis of molecular variance) results. Key results: The results of association analysis based mixed linear model (MLM) and general linear model (GLM) indicated that T(GA)9- 5 marker had a highly significant relationship (P < 0.0001) with leaf area trait. Also, T(GA)9- 5, (AG)8T- 1, (GTGC)4- 8 and T(GA)9- 1 markers showed a strong association with dry leaf weight. Four markers T(GA)9- 5, (AG)8T- 1, T(GA)9- 2 and T(GA)9- 1 had a strong relationship (P < 0.009) with dry stem weight. (GA)9T- 12, T(CA)8- 7 and T(CA)8- 12 markers indicated a significant relationship with plant height based on both MLM and GLM models. Conclusions: Defined markers could be suitable candidates to be used for marker-assisted breeding techniques in henna. Implications: In association between molecular markers and morphological traits, it is necessary to evaluated population structure to elude a false relationship between markers and morphological traits which was rarely done in henna as an important medicinal plant.