Genetic diversity and population structure analyses of Morinda tomentosa Heyne, with neutral and gene based markers

Abstract

Morinda tomentosa Heyne (Rubiaceae) an evergreen small tree also known as Aal or Indian Mulberry or Nunaa has broad range of therapeutic and nutritional value and is broadly used for making morindone dye for the dyeing of silk, cotton and wool. This is the first report wherein twenty genotypes of M. tomentosa, an underutilized fruit plant collected from Madhya Pradesh, India were studied for genetic diversity analyses using 131 Start Codon Targeted Markers (SCoT) (gene based) and 97 Random Amplified Polymorphic DNA (RAPD) and 70 Inter Simple Sequence Repeat (ISSR) (neutral) markers. SCoT markers showed the highest level of polymorphism, Shannon’s Information Index and Polymorphism Information Content (70.23 %; 0.31 ± 0.27; 0.189 ± 0.103), while the total number of bands per primer (7.0) was highest for ISSR markers. Nei’s gene diversity (0.20) was found similar for both ISSR and SCoT markers. And geographical clustering was most pronounced with ISSR followed by SCoT and RAPD markers. Cumulative marker data revealed best clustering of genotypes based on their areas of the collection. And individually, our results showed the efficacy of both SCoT and ISSR (co-phenetic correlation values of 0.79 and 0.76 respectively) over RAPD (co-phenetic correlation value of 0.69) markers for genetic diversity and geographical patterning studies of M. tomentosa. Additionally, structure analysis grouped the twenty M. tomentosa genotypes into two sub-populations, this structuring and the identified markers can be utilized for making further strategies for collection and conservation of M. tomentosa from Madhya Pradesh and other states of India as well as for global collections.