Effect of Kiwifruit Vine Decline Inducing Soils on Growth, Mineral uptake, and Protein Content in Different Actinidia Genotypes Radical Systems

The Kiwifruit Vine Decline Syndrome (KVDS) is a sever disease, which is causing dramatics yield losses and economic damage. Primary identified in Veneto region, nowadays, it is present worldwide. Concerning symptoms, in the radical system is possible to note a widespread root rot and absence of feeding roots. Furthermore, a wilting of leaves appears, which, as consequence, shortly brings to a total collapse of the whole plant. The disease is caused by both biotic and abiotic factors, enhanced primary by soil borne pathogens and waterlogging conditions. Up to date, there is not any effective managing strategy, and the disease is still being studied. Nevertheless, the availability of a large Actinidia germplasm collection open up to the possibility of screening different species in order to find traits to contrast KVDS. In this context, we selected 4 species of Actinidia (A. macrosperma, A. deliciosa, A. arguta and ‘Sav1’ cultivar), planted in KVDS inducing soils, and evaluated the radical system after one vegetative season. Abiotic and biotic stresses induce numerous biochemical and physiological responses in plants, commonly identified as a different capability of mineral up taking and protein degradation, as well as growing differentiation. For these instances, the different genotypes attitude to grow in KVDS inducing soils was evaluated. Hence, the growth of the radical system was determined, taking into account a measure such as the volume. Indeed, the concentration of mineral elements was measured by using the Inductively Coupled Plasma-Atomic Emission Spectrometry, while the total protein content was measured through the Bradford assay. Yet, discontinuous sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed in order to separate proteins and then determining their patterns. The results showed that there exist significant differences regarding the growing capability in KVDS inducing soils among the tested genotypes. Interestingly, there were a different content in terms of mineral elements in roots, as well as the protein content. Surprisingly, no differences were found on protein’s patterns. These first evidence demonstrated how different Actinidia species were able to grow in these soils, showing a different capability of nutrient uptake and protein content. Thus, compared to that already known as sensitive (e.g., Actinidia deliciosa cv. Hayward), the tolerant genotypes had a better performance of the radical system.