Exploiting the mango genome: molecular markers V. Pérez and J. I. Hormaza, Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM La Mayora – CSIC – UMA), Spain

1 Introduction

2 Biochemical markers

3 DNA markers

4 Other molecular markers

5 Next-generation sequencing technologies

6 Genetic linkage maps

7 Other ‘omics’

8 Future trends and conclusion

9 Where to look for further information

10 Acknowledgements

11 References

Mango (Mangifera indica L., Anacardiaceae) is a woody perennial fruit crop with 40 chromosomes, and a total genome size of 439 Mb (Arumuganathan and Earle, 1991), about three times the size of the model plant Arabidopsis thaliana (L.) Heynh., and has been described as allotetraploid (Mukherjee, 1950). Mango belongs to the Mangifera genus that includes approximately 69 species, from tropical Asia, in two subgenuses, Limus and Mangifera (Kostermans and Bompard, 1993). Taxonomic and molecular evidence supports an origin of mango within a large geographical area that includes northwestern Myanmar, Bangladesh and Northeastern India (Bompard, 2009; Mukherjee, 1972; Mukherjee and Litz, 2009). Mango domestication of monoembryonic varieties probably originated in India where over 1,000 varieties are recognized, most of them selections from naturally occurring open-pollinated seedlings (Iyer and Degani, 1997). Mango cultivation spread outside its centre of origin and domestication throughout many tropical and subtropical regions of the world along trading routes, resulting in selections of genotypes adapted to particular edaphoclimatic conditions (Bompard, 2009; López-Valenzuela et al., 1997;

Mukherjee and Litz, 2009). Because of the crosses performed during the twentieth century in the frame of a breeding programme, Florida is often considered as a second centre of diversity of mango that has resulted in the development of important commercial mango varieties that are cultivated in new growing areas worldwide (Mukherjee, 1997). This long period of mango cultivation in different regions has resulted in a high number of varieties, traditionally identified with morphological markers. In order to standardize this phenotypic characterization, descriptors that include phenological and morphological traits of flowers, leaves, fruits and seeds have been developed for mango (IPGRI, 2006). Morphological characterization is necessary for adequate cultivar identification and, especially, good phenotyping (Rajwana et al., 2011), which is ultimately needed to efficiently link molecular markers with traits of interest and accelerate breeding programmes. However, it is also inaccurate due to the influence of the environment and the phenological status of the plants and the limiting number of discriminating traits (Khan et al., 2015). Thus, molecular markers provide a highly reliable complement to morphological markers, especially for cultivar fingerprinting and diversity studies.