Molecular characterization of Kinnow mandarin clones and mutants using cross genera SSR markers

Abstract

Kinnow mandarin is a highly priced commercial citrus fruit for domestic as well as overseas markets. Excessive numbers of seeds in the fruit makes it less preferred mandarin for dessert as well as processing purposes. Attempts were made in the past to collect superior less seeded clones of Kinnow. Besides, efforts were also made to induce variation in Kinnow using physical (γ-ray) and chemical (ethyl methanesulphonate) mutagens. The non-availability of SSR makers in Kinnow made us look into cross genera marker polymorphism and characterization of these clones. The present study demonstrated the cross-genera transferability of simple sequence repeat (SSR) markers developed in citrus and chickpea to Kinnow mandarin clones and mutants. Out of 87 primers tested (67 from chick pea and 20 from citrus), 11 primers (8 citrus and 3 chickpea) showed polymorphism and amplified 14 alleles. Of 67 SSR loci (chick pea), 3 (4.47 %) gave cross-amplification. The polymorphic information content (PIC) value ranged 0.14 to 0.99, while Jaccard’s similarity coefficients ranged 0 to 0.9. Clustering pattern showed that all the mutants and clones distinctly grouped and were different from the parent. It showed that mutants and clones had distinct molecular changes in them. In principle coordinate analysis,the first three coordinate axes accounted for 67.86% of the variation observed. Further, analysis of molecular variance (AMOVA showed 80%genetic variation within the population and 20% among the population.