Overcoming juvenility in an olive breeding program

Resumen del trabajo presentado en el VI International Symposium on Olive Growing, celebrado en Évora (Portugal) del 09 al 13 de septiembre de 2008.

One of the main drawbacks in olive breeding is the lengthy juvenile period which must be overcome in order to evaluate flowering and fruiting characteristics. In the framework of an olive breeding program, we are attempting to overcome this problem following two strategies. The first one is to use cultural practices aimed at increasing the number of olive seedlings with early flowering and, therefore, able to be evaluated. In this sense, the optimum height for transplanting to the field seems to be 100 cm. Also, characterization of the juvenility cone in olive seedlings has shown that 100 cm is the optimum height to form the canopy. The second strategy to overcome juvenility is that of developing early selection criteria for the length of the juvenile period. Plant height and the number of lateral shoots, measured in the greenhouse, seem to be good criteria to eliminate plants with long juvenile period later in the field. Additionally, other markers of the phase change apart from the onset of flowering are under study. On one hand, leaves from juvenile and adult shoots appear to differ in their histological organization. On another, a gene called JAT showed an expression in juvenile tissue much higher than that in adult tissue.

Peer reviewed