EDGARDO GIORDANI

Feijoa sellowiana (O. Berg) is a broadly widespread fruit tree species at a very early stage of domestication. Although appreciated for its flavored berries rich in nutrients and nutraceuticals, and as an ornamental plant, feijoa is still considered an underutilized species and little information is available about its genetic background, cultivar traceability and divergence. This study aimed to investigate, for the first time, the genetic diversity of feijoa through the application of AFLPs. Specifically, twenty cultivars from different countries and six wild types (WTs) from their area of origin (Misiones, Argentina) were analyzed. The AFLPs proved to be informative, revealing the values of the percentage of polymorphic loci (PPB), Nei’s genetic diversity (h), and the Shannon index (I) at 69.36%, 0.27, and 0.43, respectively, consistent with the average of long-lived perennial and outcrossing species. However, despite the limited number of WTs examined, the genetic variability (h) was higher (approximately 37%) within the six samples compared to cultivars. The population structure analysis identified three clusters, with WTs forming a separated cluster (III) as expected. Cultivars were divided into two clusters (I and II), with cluster I exhibiting a closer genetic proximity to WTs compared to cluster II. This finding was further confirmed using the UPGMA dendrogram based on Provesti distances. This work raised awareness of the genetic variability among the feijoa’s widespread cultivars and demonstrated that the limited genetic breeding programs over the last decades resulted in low diversity among them. Moreover, these results confirm the hypothesis that all varieties are derived from a single narrow ancestral population. The potential of this species is considerable and needs to be further investigated to exploit its peculiarities.

Treated water reuse is vital for sustainable water management and reducing the strain on freshwater resources, particularly in agriculture, which has a great impact on freshwater withdrawal. Despite the benefits, the reuse of treated wastewater carries risks due to residual chemical and microbiological contaminants, such as the organic micropollutants polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), which are not fully removed by current treatment processes and can affect plant growth and human health when used for irrigation. This study focuses on monitoring the PAHs and PCBs in wastewater used for irrigating strawberries, assessing their transfer to crops and potential health risks. The effluents of four wastewater treatment plants were monitored for two years (2017 and 2018) and used to irrigate strawberries grown in plot installations. Effective and robust analytical methodologies (60–99% recoveries, optimal reproducibility) were developed for wastewater and strawberry analysis. The analysis of the treated wastewaters showed the presence of residual PAH and PCB concentrations at hundreds of ng/L. The strawberry crops were further analyzed to measure the PAHs and PCBs. Since two PAHs were present in strawberries, a risk assessment was performed (EPA methodology), finding that the residual contamination of treated waters does not pose a significant health risk, for both adults and children, through the consumption of fruits.