Tree and root architecture of Malus sieversii seedlings for rootstock breeding
2014
Fazio, G. | Chao, C. T. | Forlsine, P. L. | Richards, C. | Volk, G.
The foundation of a successful apple orchard is in large part the rootstock used to establish the trees in that orchard. Apple root stocks can impart several important architectural tree characters to the scion, among which are reduction in tree size and early production of flowers/fruit. It is probable that similar root-mediated characteristics exist in natural ancestral apple populations such as Malus sieversii, a species known to have traits associated with tolerance to several biotic and abiotic stresses. We sought to understand the genetic determinism of tree architecture of M. sieversii seedlings by measuring several scion and root architecture characters on a total of 1,180 high resolution images of dormant 1-year-old trees. These images were analyzed to ascertain number of growing points (tips), tree volume and total length of branch canopy, flat branching, presence of spines, root mass, number of primary roots, and number of thick roots. Analysis of means revealed significant inherited differences for several traits related to tree and root architecture, especially for flat branching, presence of spines, number of primary roots and root mass. Such differences were also detected among sites of origin of the mother trees. We have used this data to select parents for a new generation of root stocks that will be evaluated in years to come.
显示更多 [+] 显示较少 [-]