Fungal Volatile Organic Compounds (VOCs) repel banana black weevil (BW), Cosmopolites sordidus (Germar, 1824), the key-pest of banana [Musa sp. (Linnaeus, 1753)]. The entomopathogens Beauveria bassiana (Bb1TS11) and Metarhizium robertsii (Mr4TS04) were isolated from banana plantation soils using an insect bait. Bb1TS11 and Mr4TS04 were pathogenic to BW adults. Bb1TS11, Bb203 (from infected palm weevils), Mr4TS04 and the nematophagous fungus Pochonia clamydosporia (Pc123), were tested for VOCs production. VOCs were identified by Gas Chromatography/Mass Spectrometry–Solid-Phase Micro Extraction (GC/MS-SPME). GC/MS-SPME identified a total of 97 VOCs in all strains tested. Seven VOCs (styrene, benzothiazole, camphor, borneol, 1,3-dimethoxy-benzene, 1-octen-3-ol and 3-cyclohepten-1-one) were selected for their abundance or previous record as insect repellents. In olfactometry bioassays, BW-starved adults in the dark showed the highest mobility to banana corm. 2-cyclohepten-1-one (C7), commercially available isomer of 3-cyclohepten-1-one, is the best BW repellent (p < 0.05), followed by 1,3-dimethoxy-benzene (C5). The rest of the VOCs have a milder repellency to BW. Styrene (C1) and benzothiazole (C2) (known to repel palm weevil) block the attraction of banana corm and BW pheromone to BW adults in bioassays. Therefore, VOCs from biocontrol fungi can be used in future studies to biomanage BW in the field.
Fungal Volatile Organic Compounds (VOCs) repel banana black weevil (BW), Cosmopolites sordidus (Germar, 1824), the key-pest of banana ( Musa spp.). The entomopathogens Beauveria bassiana (Bb1TS11) and Metarhizium robertsii (Mr4TS04) were isolated from banana plantation soils using an insect bait. Bb1TS11 and Mr4TS04 were pathogenic to BW adults. Bb1TS11, Bb203 (from infected palm weevils), Mr4TS04 and the nematophagous fungus Pochonia clamydosporia (Pc123), were tested for VOCs production. VOCs were identified by Gas Chromatography/Mass Spectrometry - Solid-Phase Micro Extraction (GC/MS-SPME). GC/MS-SPME identified a total of 97 VOCs in all strains tested. Seven VOCs (C1 – C7) were selected for their abundance or previous record as insect repellents. BW starved adults in the dark showed the highest mobility to banana corm in olfactometry bioassays. C7, produced by all fungal strains, is the best BW repellent (p<0.05), followed by C5. The rest of VOCs have a milder repellency to BW. C1 and C2 (known to repel palm weevil) block the attraction of banana corm and BW pheromone to BW adults in bioassays. Therefore, VOCs from biocontrol fungi can be used in future studies for biomanagement of BW in the field.
Pomegranate (Punica granatum L.) is a strategic crop for Mediterranean agriculture due to its adaptability to arid environments—an increasingly important trait in the context of climate change—and its rising market demand driven by nutritional and medicinal properties. To support breeding and conservation efforts, this study evaluated the genetic diversity and phenotypic traits of two Mediterranean germplasm collections from Elche (Spain) and Bari (Italy). A total of 184 accessions were analyzed using SSR markers and evaluated for key pomological and phenological traits, including fruit weight, skin and aril color, seed hardness, aril weight, titratable acidity, soluble solids content, and harvest time. Genetic analyses revealed high levels of diversity within and between collections, with clear population structure influenced by geographic origin. Phenotypic evaluation revealed considerable variation in agronomic and quality traits, and several accessions with notably desirable characteristics were identified. For example, Ovadan and Molla Nepes displayed very high soluble solids content (>19 °Bx), Sanrà Nero, Sanrà Rosso, and Tajikistan Dark Red exhibited titratable acidity exceeding 40 g/L citric acid, and De Marco reached aril weights of up to 0.60 g. The integration of molecular and morphological data provided valuable insights into the distinctiveness and breeding potential of the studied genotypes. Misclassifications were identified, as well as phenotypic differences attributable to environmental influences. These findings highlight the importance of characterizing regional germplasm to preserve local adaptations and support development of new cultivars adapted to changing environmental conditions. This work reinforces the role of European pomegranate collections as reservoirs of genetic resources for sustainable cultivation and future breeding programs.
Banana ( Musa spp.) is essential for food security. For its clonality is highly susceptible to pests and diseases. The wilt fungus Fusarium oxysporum f. sp. cubense Tropical Race 4 (FocTR4) threatens banana production worldwide. We notice that chitosan protects banana from biotic stress. Chitosan, a plant defence elicitor with antimicrobial activity, triggers salicylic acid (SA) and methyl salicylate biosynthesis and induces systemic acquired resistance (SAR) genes, mainly flavin-dependent monooxygenase 1 (FMO1), in banana. Chitosan promotes root exudation of SA and emission of methyl salicylate (MeSA). Banana germplasm, Petit Naine , Gros Michel , Enzirabahima , Yangambi Km5 and Foconah banana differ in their response to chitosan. Chitosan induces, in Foc resistant Yangambi Km5 , ca. 7-fold FMO1. Preventive chitosan treatments together with the endophytic biocontrol fungus Pochonia chlamydosporia strain 123 reduce (ca. 4-fold) colonization of banana roots by FocTR4. Therefore, chitosan and beneficial endophytes can help to manage sustainably FocTR4 in banana.