Weill Cornell Medical College-Qatar (WCMC-Q) researchers have identified a region of the date palm genome linked to gender, making it possible for the first time to quickly and easily identify male and female trees, a crucial piece of information which will greatly facilitate additional genetic studies as well as cultivation and propagation.
“Our evidence shows that date palm employs an XY system of gender inheritance similar to that of humans,” says Joel Malek, director of the genomics lab and senior author of the study, which was published online today by the journal Nature Biotechnology.
“How date palm gender is determined has been a question for thousands of years with numerous theories presented in the past. We now have the first DNA sequence evidence that it is under genetic control though the gender control region appears quite small making its discovery difficult,” he added.
Date palm is a dioecious species, that is, individual plants are either male or female. Consequently, half of the seedlings grown for cultivation will be males and half will be females. Female trees bear the fruit, making them much more valuable than male trees, which serve only as pollinators. Early identification of the more valuable female trees is difficult because it takes about five to eight years for female seedlings to bear the distinguishing fruit.
“A simple and reliable way to distinguish between male and female seedlings has long been sought not only for agricultural purposes but also to promote basic date palm studies, which have been hindered by dioecy and long generation times,” says Malek. Two years ago, he and WCMC-Q colleagues sequenced a draft version of the date palm genome.
The WCMC-Q research team cooperated with the Biotechnology Centre at the Ministry of Environment in Qatar which provided date palm samples to support their research. “Identifying the genes related to specific date palm characteristics will certainly help us find solutions to problems faced by date palm plantations in Qatar, especially as far as diseases affecting date palm trees are concerned,” said Masoud Al Marri, Director, Biotechnology Centre, Ministry of Environment.
“This research will also explore the unique characteristics of the date palm tree such as its tolerance to salinity and high temperatures, and ways of making other plants tolerate such extreme conditions by genetic modification, ie transferring genes from date palm trees to other plants,” he added.
The WCMC-Q research used samples that were part of a date palm breeding program carried out in California from 1948 to 1974 and incorporated into a national repository, which maintained the lines as part of a mission of conservation of genetic resources, says Krueger, who served as curator of the collection. The repository is operated by USDA’s Agricultural Research Service.
Copyright © 2011 Peninsula News Paper.
