Researchers at Weill Cornell Medicine – Qatar (WCM-Q) can now predict whether a date palm seed will produce a male or female plant with effectively 100 percent accuracy – and with huge implications for the commercial use of the plant.

Date Palm
Heavily laden with fruits (Wikipedia)

The team led by Dr Joel Malek, Assistant Professor of Genetic Medicine and Director of the Genomics Core at WCM-Q, already knew that the sex of the date palm plant is determined by the XY system, whereby the male of the species determines the sex of the offspring, similar to the way that human gender is determined. They also knew that a large region of genes appear to be always associated with gender but were unclear on the specific DNA responsible.

That uncertainty has now been solved, and in doing so the research team has discovered how to predict the sex of all 14 palm tree species within the Phoenix genus – the genus that contains the date palm. They did this by decoding the genome of each species to calculate which genes appeared in the male plants but not in females.

According to Dr Malek, the mechanism was narrowed down to four genes that every male plant in the entire genus had, but that were absent in the female plants. Essentially, those four genes are responsible for a tree producing pollen. He said that the Phoenix genus was one of only a few examples where the sex determinants are the same across the entire genus.

The discovery, which has been reported in the journal Nature Communications could have major implications for both commercial agriculture and horticulture.

Fresh date fruits
Fresh date fruits (Wikipedia)

For farmers growing date palms and harvesting the fruit, it is important to have as many female plants as possible to maximise crop yields. Similarly, city planners and landscape gardeners who plant palm trees for aesthetic reasons prefer male plants, as they do not produce fruits which must be cleared.

Farmers must traditionally wait four or five years to know whether the trees they planted will yield fruit or pollen. Genetic testing of the seeds can ensure that a high ratio of female plants are grown, and only a few male plants cultivated for pollination purposes.’

The genetic test can also be used on other species in the genus such as the Canary Island date palm, extremely widespread for use in landscaping.

Future research will soon see Dr Malek and his team identifying the genes in date palm which control features such as size, sweetness and texture, along with its resistance to certain diseases and stress factors like drought. The research was funded by a grant from the Qatar National Research Fund, a member of Qatar Foundation.

For updates and more information about the latest WCM-Q research, visit qatar-weill.cornell.edu.

Image cover: From left, researchers Lisa Mathew, Yasmin Mohamoud, Joel Malek and Karsten Suhre.