Alternaria species causing pomegranate and citrus fruit rots in Albania

The fungal genus Alternaria is a relevant pathogen for several commodities including citrus and pomegranate fruits. On citrus, it mainly causes brown spots on fruits and leaves, whereas on pomegranate, it mostly causes a fruit heart rot. In the present study the presence of Alternaria rots on citrus and pomegranate fruits cultivated in Albania was assessed. Representative fruits were collected from different regions. Nineteen and thirteen Alternaria spp. isolates were obtained from pomegranate and citrus samples, respectively. The isolates were identified at species and morphotype level. Micro and macroscopic features separated isolates into four morphotypes. BLAST and phylogenetic analysis using the SCAR Marker OPA1-3 confirmed the isolate identity. All 32 isolates proved to be Alternaria alternata and belonged mainly to morphotype alternata, followed by limoniasperae and tenuissima. All Alternaria strains proved to possess the pksI gene of alternariol biosynthesis. Citrus isolates were tested for the presence of genes of the biosynthesis of the phytotoxins ACT and ACR, but none of them proved to possess them. Concluding, Alternaria spp. might represent a treat to pomegranate and citrus production in Albania, and thus effective control means are needed

Regeneration of Algerian

Stigma/style somatic embryogenesis is one of the efficient methods in plant regeneration of most Citrus ssp., without inducing somaclonal variations. Furthermore, somatic embryogenesis from style/stigma proved to be effective in the elimination of the main citrus virus and virus-like diseases. This technique was applied on Algerian citrus collection. Different Citrus species [Citrus sinensis (L.) Osbeck, C. limon (L.) Burm, C. reticulata Blanco, C. paradisi Macfad, C. reshni Hort. ex Tan., C. jambhiri Lush and C. maxima (Burm.) Merrill] were chosen and tested for the presence of the main virus and virus-like agents. Most of the genotypes showed to be infected, mainly by viroid agents. Closed flowers were collected and in vitro cultured on a Murashige and Skoog (MS) medium supplemented with 6- benzylaminopurine. All explants produced callus about 4 to 9 days after culture initiation, whereas embryogenesis occurred after 38 to 150 days in most of the cultured genotypes. Formed embryos were cultured in a single tube before in vivo acclimatization. After sanitary assays, regenerated plants were shown to be free from the agents detected in the mother trees.Key words: Algeria, citrus germplasm, plant regeneration, sanitation, somatic embryogenesis

Evaluation of some growth regulator effects on encapsulated in vitro-derived microcuttings of three Italian Ficus carica L. genotypes.

In this study, the encapsulation technology based on the calcium alginate coating was applied to some Ficus carica L. genotypes. Uninodal microcuttings (3-4 mm long), excised from in vitro proliferating shoots of three Italian cultivars (‘Bifera’, ‘Palazzo’ and ‘Catalanisca’), were employed. The influence of three different plant growth regulators (PGRs): 6-benzylaminopurine (BAP), meta-topolin (MT) and zeatine (ZEA), added to the artificial endosperm, were evaluated. Particularly, the viability, regrowth and conversion parameters of the synthetic seeds were registered after 60 days from the sowing on a hormone-free medium. Results showed that the cultivars ‘Catalanisca’ and ‘Palazzo’ showed the highest viability average rate (90%), followed by ‘Bifera’ (80%). Encapsulated microcuttings regrowth percentage was highest for ‘Palazzo’ (86.7%), followed by ‘Catalanisca’ (81.7%) and ‘Bifera’ (66.7%), while the conversion rate was comparable for the three cultivars (43.4, 40.0 and 48.3%, respectively). A strong interaction between cultivars and PGRs was observed. Moreover, regarding the effect of the PGRs, BAP and MT provided the best results about regrowth and conversion, even if the cultivar ‘Catalanisca’ presented 100% of regrowth with ZEA. To our knowledge, this is the first time, that encapsulation technology has been applied to Italian cultivars of Ficus carica

Alternaria species causing pomegranate and citrus fruit rots in Albania

The fungal genus Alternaria is a relevant pathogen for several commodities including citrus and pomegranate fruits. On citrus, it mainly causes brown spots on fruits and leaves, whereas on pomegranate, it mostly causes a fruit heart rot. In the present study the presence of Alternaria rots on citrus and pomegranate fruits cultivated in Albania was assessed. Representative fruits were collected from different regions. Nineteen and thirteen Alternaria spp. isolates were obtained from pomegranate and citrus samples, respectively. The isolates were identified at species and morphotype level. Micro and macroscopic features separated isolates into four morphotypes. BLAST and phylogenetic analysis using the SCAR Marker OPA1-3 confirmed the isolate identity. All 32 isolates proved to be Alternaria alternata and belonged mainly to morphotype alternata, followed by limoniasperae and tenuissima. All Alternaria strains proved to possess the pksI gene of alternariol biosynthesis. Citrus isolates were tested for the presence of genes of the biosynthesis of the phytotoxins ACT and ACR, but none of them proved to possess them. Concluding, Alternaria spp. might represent a treat to pomegranate and citrus production in Albania, and thus effective control means are needed

Fig virus-free production and survival rate improvement using meristem tip culture techinique associated with the encapsulation technology

Three Mediterranean F. carica genotypes, i.e. cultivars Palazzo, Bifera nera and Catalanisca, initially infected by Fig leaf mottle-associated virus 1 (FLMaV-1), Fig leaf mottle-associated virus 2 (FLMaV-2), Fig mild mottling-associated virus (FMMaV), Fig mosaic virus (FMV), Fig latent virus 1 (FLV-1), Fig Badnavirus 1 (FBV-1) and Fig fleck-associated virus (FFkaV), were subjected to the sanitation technique via Meristem Tip (0.3-0.5 mm in size) Culture (MTC), also associated with the encapsulation technique (MTC-SS), in order to produce virus-free plant material. Encapsulation was tested to overcome the very low survival and regeneration rates, due to the small propagule size. Encouraging results were obtained in term of regeneration rate, where Bifera nera showed the best one, followed by Palazzo and Catalanisca. The sanitary status of all genotypes was assayed by RT-PCR using viruses-specific primers. FLMaV-1 was completely eradicated from the regenerated plantlets. FMMaV and FFkaV were highly and equally eliminated, followed by FLV-1 and FMV. The only DNA virus (FBV-1) resisted to this sanitation attempt

Viruses infecting different Mediterranean genotypes of Ficus carica and their distribution in different plant organs.

Seven Mediterranean Ficus carica genotypes, i.e. cv. Palazzo, Severoni precoce, Bianca, Pilusedda, Dottato bianco, Bifara and Zidi, were screened for the presence of seven fig-infecting viruses associated with fig mosaic disease (FMD) in order to explore their distribution in different plant organs (leaf, bud and syconium) that will be utilized as a plant source material in different sanitation techniques. RT-PCR assays conducted on reverse-transcribed TNA extracted from leaves, apical buds and syconia (1.5-2cm) of each genotype for the presence of Fig leaf mottle-associated virus 1 (FLMaV-1), Fig mild mottling-associated virus (FMMaV), Fig mosaic virus (FMV), Fig latent virus 1 (FLV-1), Fig Badnavirus1 (FBV-1) and Fig fleck-associated virus (FFkaV) showed that the infection rates in tested cultivars were 72.2% for FBV, followed by FFkaV (27.4%), FLMaV-1 (18,7%) and FMV (11.1%); whereas FMMaV and FLV-1 were absent. Virus distribution within the different explants showed that FBV1 was the most prevalent in all explants with infection rates ranging between 50% and 83%, whereas FFkaV was mostly concentrated in syconia (39%) and to a lesser extent in buds (32%) and leaves (10%). The highest infection with FLMaV-1 was found in syconia (50%), where, as buds and leaves, showed a mild level of infection (25%). FMV was present in 25% and 8% of tested buds and leaves, respectively, whereas it was absent in syconi