Full genome map of oil palm indicates a way to raise yields
How the discovery will affect plantation management and land use
The discovery of the Shell gene and its two naturally occurring mutations highlight new molecular strategies to identify seeds or plantlets that will become high-yielding palms before they are introduced into plantations.
Seed producers can now use the genetic marker for the Shell gene to distinguish the three fruit forms in the nursery long before they are field-planted. Currently, it can take six years to identify whether an oil palm plantlet is a high-yielding palm. Even with selective breeding, 10 to 15 percent of plants are the low-yielding dura form due to uncontrollable wind and insect pollination, particularly in plantations without stringent quality control measures.
“Accurate genotyping for enhanced oil yields will optimize and help stabilize the acreage devoted to oil palm plantations, providing an opportunity for the conservation of rainforest reserves,” Martienssen explains.
The Malaysian government strongly supported the genome sequencing project for the nation’s most important crop. The government halted the conversion of new forest land for agriculture, including palm oil, in the 1990s. According to the MPOB, the government has committed to preserve 50 percent of Malaysia’s total land area as forest. To meet increased demand for palm oil, the government converted colonial rubber and cocoa plantations to oil palm plantations.
What the full genome sequences reveal
The discovery of Shell occurs in the context of a broader effort to map the genomes of both the African and South American oil palm species. One of the newly published maps is the 1.8 gigabase sequence of the E. guineensis African oil palm. It comprises nearly 35,000 genes, including the full set of oil biosynthesis genes and other transcriptional regulators highly expressed in the oil-rich palm fruit.
The researchers also created a draft sequence of the South American oil palm E. oleifera. Both palm species are in the Arecaceae family of flowering plants, which fossil evidence dates to the Cretaceous period, an estimated 140 to 200 million years ago. The investigators’ comparison of the two maps enabled them to estimate that the oil palm species diverged at the old world- new world split.
“Oil palm genome sequence reveals divergence of interfertile species in Old and New worlds” and “The oil palm SHELL gene controls oil yield and encodes a homologue of SEEDSTICK” will be published online ahead of print in Nature on Wednesday, July 24, 2013. The papers can be viewed then at: http://www.nature.com/nature/index.html.
For further information on the oil palm genome project, visit http://genomsawit.mpob.gov.my