Faculty of Science: Mapping of Quantitative Trait Loci Affecting Stem Height in Oil Palm

23 August 2017 (Venue : BA05)

Name : Teh Chee Keng – School of Biosciences

Chairperson : Dr Eunice Ngai

Evaluator : Dr Eunice Ngai

Title : Mapping of Quantitative Trait Loci Affecting Stem Height in Oil Palm

Abstract :
Sime Darby R&D Plantation is developing short oil palms from the Gunung Melayu dura (GM) x dumpy AVROS pisifera (DAV) origin to improve fresh fruit bunch harvestability. The aim is to increase realized crop yields when palms reach the peak productive age, which is from 9 – 18 years old. However, breeding progress is extremely slow due to long selection cycles. Marker-assisted selection is known as a potential solution to accelerate genetic gains over generations. A total of 11,653 SSRs were mined from the reference genome. Two related populations derived from GM x GM with a mean stem height of 142.4 cm (± 25.46) and GM x DAV with a mean of 206.4 cm (±35.87) are significantly shorter than their respective DxP control. This suggests that dumpiness is highly heritable in GM x DAV population. To date, a preliminary linkage map for GM x GM population with a 6.5 cM average mapping interval was constructed using 67 linked SSRs. Interval mapping for QTL is not feasible due to insufficient marker density and genome coverage, so only Kruskal-Wallis tests were applied. Five significant stem height-linked SSRs on three linkage groups were detected at p-value < 0.05. The map will be further improved for a better genome coverage by including more informative SSRs and SNPs. The same analysis will be extended to GM x DAV population to understand QTL inheritance for dumpiness traits in both origins. In conclusion, this study provides a good starting point to understand the QTL underlying stem height in oil palm.