Phenomenon responses of two kiwifruit genotypes to calcareous and iron treatment in pot experiments

Abstract

Screening Fe deficiency-tolerant genotypes is an environment-friendly and long-term effective strategy to cope with bicarbonate chlorosis stress in kiwifruit. We investigated the physiological response of two Actinidia chinensis var. deliciosa genotypes, cv. ‘Hayward’ and cv. ‘Tomuri’, when grown in the control solution (20 µM FeEDDHA, Ct) and two iron-deprived conditions: (1) no Fe (0 µM FeEDDHA, -Fe) and (2) induction of Fe deficiency by adding10 mM HCO 3 (Bic). After 45 treatment days, the -Fe and Bic plants exhibited leaf chlorosis symptomatology, as detailed by all the parameters, especially under the Bic conditions. The photosynthesis rate and the Fv/Fm time-course measurements reflected damage to leaf photosystems from early time points, especially in Hayward. The strategy I responses (reduction and acidification capacities) generally reduced, especially by the Bic treatment in both genotypes. However, Tomuri presented a more optimized system for mobilizing root Fe and maintaining photosynthetic activity with the Bic treatment by keeping proton and the Ferric Chelate Reductase levels better than Hayward. The most marked drop was for Chl in the Tomuri -Fe results from no Fe and biomass reduction, while the more attenuated decrease in Hayward depended only on ion nutrition. The results contribute by identifying potential responses in kiwifruit for Fe deprivation tolerance in calcareous soils.

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