Genetic Analysis and Trait Association in Multi-parent Advanced Generation Inter-Cross (MAGIC) F2 Population of Tobacco (Nicotiana tabacum L.)

Abstract

Genetic variability studies offers basic information related to genetic properties of the population based on which breeding methods could be formulated for further improvement of the crop. The estimates of heritability, coefficients of variability and genetic advance was calculated in a multi-parent advanced generation inter-cross (MAGIC) F₂ segregating populations for 10 traits including nicotine percentage, total soluble sugars and yield contributing traits during 2015 seasons at Northern Light Soils (NLS). The estimates of phenotypic coefficients of variation (PCV) were high and moderate for plant height (18.16%), number of leaves (15.96%), leaf area index (27.35%), internodal length (21.01%), stem diameter (16.73%), grade index (13.86%), nicotine percentage (19.87%), total soluble sugars (39.81%), chlorides (23.35%) and leaf yield (13.27%) in MAGIC-F₂ segregating populations at NLS 2015 season. High heritability coupled with high and moderate genetic advance was observed for all the traits studied. Correlation studies revealed that total soluble sugars was positively and significantly correlated with leaf area index, stem diameter, grade index and leaf yield. However total soluble sugars was negatively correlated with nicotine as total nicotine alkaloid and with chlorides percentage. Path coefficient analysis revealed that total percentage of sugars could be improved through selection of grade index, stem diameter, leaf area index and cured leaf yield which were positively correlated with total soluble sugar percentage. The current study also revealed that the MAGIC F₂ population could be used for development high sugar lines with moderate or low levels of nicotine and chlorides in tobacco.