SCREENING PRUNUS ROOTSTOCKS FOR TOLERANCE TO IRON CHLOROSIS

The use of rootstocks tolerant to iron-induced chlorosis represents a reliable solution to prevent Fe chlorosis in stone-fruit production in calcareous soils.
The development of a laboratory screening procedure allows selection of new Prunus rootstocks tolerant to iron chlorosis.
Micropropagated plants were grown hydroponically in a growth chamber.
Plants were first grown in a 1/2 strength Hoagland nutrient solution with 90 μM of Fe-EDTA as a control treatment.
Then, three out of four plants were grown for four days without iron.
Thereafter, two out of three plants were re-supplied with 180 μM of Fe(III)-EDTA for 1 or 2 days.
In vivo root iron reductase (FC-R) activity was measured in the treatments: controls, Fe deficient plants and plants resupplied with 180 μM of Fe-EDTA. The FC-R activity in the Fe-efficient genotypes such as AC 9921-07, ‘Adesoto’, ‘Felinem’, GF 677 and Kuban 86 was higher after the Fe was added than that found in the controls.
No induction was found in other genotypes considered Fe-inefficient like ‘Barrier’ and ‘Cadaman’. An intermediate performance was found in AC 9907-02, Gisela 5, ‘Garnem’, ‘Torinel’, VSL-2 and VVA-1. According to the induction of FC-R activity, genotypes were classified as tolerant, moderately tolerant or non-tolerant to iron-induced chlorosis.
These results were compared with chlorophyll readings (SPAD measures) carried out in the orchard for some of the rootstocks studied.
Tolerant rootstocks, such as Adesoto and GF 677, gave values higher than 35. Moderately tolerant rootstocks like AC 9907-02, Gisela 5, ‘Garnem’, ‘Torinel’, VSL-2 and VVA-1 showed readings higher than 30 whereas non-tolerant rootstocks such as ‘Barrier’ had SPAD values of less than 30.

XI Eucarpia Symposium on Fruit Breeding and Genetics

S. Jiménez, A. Santos, A. Abadía, J. Abadía, J. Pinochet, M. Cunill, M.A. Moreno, Y. Gogorcena

peach, ferric-chelate reductase activity

https://doi.org/10.17660/ActaHortic.2004.663.144