ISHS Acta Horticulturae 441: V Temperate Zone Fruit in the Tropics and Subtropics
MICROGRAFTING AS A NEW RAPID METHOD FOR SELECTION OF INDIGENOUS TUNISIAN GRAPEVINE VARIETIES |
| Authors: | F. Ben Abdallah, A. Fnayou, A. Ghorbel |
| Abstract:
In spite of their efficiency, sanitary and genetic selection methods require a long period of time, particularly for local grapevine varieties. When perfectly performed, micrografting might be a rapid selection method; however, apices taken from field plants did not improve the percentage of successful grafts more than 10–15%. Such failures were directly related to the higher incidence of browning and drying apices. On the other hand, use of sand media or in vitro techniques did not improve results with micrografting. To overcome these constraints, pretreatments of the scion apex as well as the rootstock were considered necessary. Given the necessity for pretreatment, our results (Ben Abdallah et al., 1996) have shown a significant improvement in grafting success (57%). An alternative method is to use higher concentrations of MgSO4 (450 mg/L), and Fe-EDTA (40 mg/L) supplemented with benzylaminopyrine (BAP; 2mg/L) and naphtaleneacetic acid (NAA; 0.1 mg/L). Accordingly, we obtained a high graft take (63%) by using rockwool-grown seedlings as rootstocks. The placement of the apex on the outward cortical surface of the hypocotyl plays a significant role in increasing success and reducing by 35 to 36% the incidence of browning and drying of apices. The technique was applied to three local varieties adapted to dry and salt conditions that are of economic and agronomic importance. | |
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