Association Analysis for Morphological Traits in Cultivated Alfalfa using Molecular Markers

In the current investigation, 10 IRAP, 14 REMAP, 16 ISSR and 7 SSR primers and mixed linear model (MLM)-based association analysis were used to identify molecular markers associated with 13 morphological traits in cultivated alfalfa (Medicago sativa L.). Morphological traits studied, were height, chlorophyll content, total wet weight, total dry weight, wet leaf weight, dry leaf weight, wet stem weight, dry stem weight, number of leaves, number of stems, number of leaves/number of stems, dry leaf weight/dry stem weight and total dry weight/total wet weight. Analysis of genetic structure of the populations revealed 6 sub-populations (K=6). In general, MLM association analysis identified 95 markers associated with studied traits (P≤0.02). Fifty-four percentages of the associated markers were retrotransposon-based markers (IRAP and REMAP), while SSR and ISSR markers constituted 46 percentage of the associated markers. Marker ISSR14-4 was associated with 8 traits. The maximum number of markers (13) was associated with dry stem weight. Markers associated with dry stem weight and wet stem weight was also linked to the other studied traits.Results of the current study presented useful information about the genetic basis of the traits studied and can be used in alfalfa breeding programs to produce hybrids with high biomass.