29 September 2010

The apple’s genome map guides cultivation towards sustainability

Aumenta dimensioni testoDiminuisci dimensioni testo

The recently published apple genome sequence and map have attracted the world’s attention to the research led by the Italian-based Edmund Mach Foundation (FEM). The results reveal the domestic apple’s history as well as help breeders striving for sustainable cultivation

About three years ago 18 research institutions coordinated by FEM got their teeth into the well-known cultivar Golden Delicious’ genome sequence. Golden Delicious is one cultivar of the domesticated apple Malus x domestica. Last year the researchers found the accurate position for over 90 percent of the genes in the apple’s 17 chromosomes through genome mapping. They have identified and mapped many genes connected to plant development, aroma and taste, reaction to the environment and disease resistance to the chromosomes.

The report shows that a genome-wide duplication (GWD) in the tribe Pyreae, to which Golden Delicious belongs, could have occurred about 50 million years ago. The researchers point out this GWD has resulted in an increase from 9 chromosomes in the old ancestor to 17 in the present. They have found that a wild apple, Malus sieversii from Central Asia is the recent wild progenitor of the cultivated apple.

Both the apple and pear belong to the tribe Pyreae. The peach is of the tribe Amygdaleae. By comparing apple’s and pear’s predicted gene spaces the researchers estimated about 96 percent nucleotide identity. Apple and peach nucleotide identity was calculated to about 90 percent.

Being the primary fruit crop of the world’s temperate zones, the apple’s genome map will have far-reaching implications when creating new varities. Growers can introduce tastier and more nutrious apples to the market quicker compared with conventional breeding.

With its more than 57 thousand putative genes, the apple has the highest number of genes of all the plant genomes studied. Breeders will find 992 of these genes involved in disease resistance paricularly interesting. It is now possible to obtain apple varities with self-defence mechanisms against insects and diseases faster, which means growers could reduce herbicides and pesticides interventions. FEM’s research is also aiming for a more eco-friendly cultivation. The publication of three million molecular markers will be helpful as researchers continue to bring the functions of the apple’s different genes to light. Currently, reserarchers are using the markers in comparative genetic studies and advanced breeding programmes FEM researchers believe should speed cultivar development.
 

youris.com provides its content to all media free of charge. We would appreciate if you could acknowledge youris.com as the source of the content.