Vol. 75 No: 4

Title:
Improved efficiency in apricot breeding: Earlier assessment of seedling progeny for resistance to plum pox virus

Authors:
M.L. BADENES, I. PASTOR, J. MARTÍNEZ-CALVO and G. LLÁCER

pp: 459-464

Abstract:
A study of apricot seed germination was conducted to evaluate the effects of chilling and exogenous growth regulators on the release of endodormancy. The objectives were to increase germination percentages and speed seedling growth to allow testing for virus resistance as soon as possible. Seedling growth patterns, along with germination percentages, were used to estimate endodormancy release. Two cultivars were used, 'Canino' and 'Real Fino'; they have different chilling requirements for release of seed endodormancy. Germination of embryos (endocarp and seed coat removed) soaked in GA₃ for 24 h was similar to that obtained with non-chilled embryos. GA₃ treatment of 'Canino' resulted in better growth only when embryos rather than intact seeds were treated. GA₃ concentration and presence of seed coat did not interact. In 'Canino' treatments of GA₃ at 200 mg l^-1 produced greater seedling-growth than standard stratification. This type of treatment with embryos is an alternative to standard stratification. In 'Real Fino', a cultivar that requires more chilling, exogenous GA₃ in non-chilled seeds could overcome the inhibition to germinate, but seedling growth was not normal. Intact seeds of 'Canino' and 'Real Fino' treated with BAP did not germinate. Embryos treated with BAP did germinate, but the seedlings were dwarfed. This implies that a minimum level of gibberellin is needed for BAP to be effective. Seeds and embryos were chilled for 10, 15, 20 and 30 d to overcome endodormancy. Embryos of both cultivars stratified for 15 d at 4°C had higher germination percentages and seedling growth than those stratified by the standard procedure (pits stratified at 4°C for 2-3 months). This new procedure allows the testing for sharka resistance one year earlier than standard procedures.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 391808 bytes)

Translate:

Go back to previous page