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One of the factors that causes low productivity of potatoes in Lebanon is the limited availability of certified seeds. The aim of this study was to establish a rapid protocol for in vitro propagation and microtuberization of potato (Solanum tuberosum L.) of Spunta variety. Meristems culture associated to thermotherapy (one month/37°C) constituted the first step. The highest percentage of reactive meristem (92%) was observed on MS medium devoid of growth regulators while MS medium containing Kin 0.4 mg.l-1, GA3 0.5 mg.l-1 and IBA 0.5 mg.l-1 yielded the highest average number of shootlets (7.8) in the seventh subculture. The lowest number of days obtained for microtuber formation was 10 and the highest average number of microtuber (1.49) was obtained with shootlets incubated under C2 culture conditions (16-h day/8-h night for initial 7 days at 25±2°C; for remaining period: continuous dark at 17±2°C). Contrary the highest microtubers average length (10.75 mm), average width (7.41 mm) and average weight (646.26 mg) were produced under C1 culture conditions (16-h day/8-h night at 25±2°C). Medium supplemented with 5 mg.l-1 BAP and 6% sucrose presented the highest average number of microtubers of 2.36 and 1.94 respectively. Type and concentration of cytokines and sucrose concentration did not have significant effect on the average length, width and weight of microtubers produced.

Modern agriculture requires technology to give precise measures of relevant parameters, such as those associated with pest control. Here, we developed an algorithm model as the basis for a bait spray intervention by monitoring the olive fruit fly Bactrocera oleae (Rossi) with conventional traps covering 24.3 hectares of non-irrigated Baladi olive cultivars in the Hasbaya region. We installed 49 yellow sticky traps with ammonium bicarbonate. The adults, both males and females, were monitored on a weekly basis. The traps and trees were georeferenced, and parameters such as the temperature, relative humidity, tree phenology (BBCH), and fruit load rate were compiled. The results show that the infested fruits were correlated equally with the fruit load rate and the number of adults captured, which in turn were correlated more with the temperature than the relative humidity. The number of males captured was higher than that of females throughout the cultivation period. The first symptoms of the fruits were observed on 22 September, when the BBCH was equal to 85, with an average number of adult captures of less than five when using traps over 7 days.

Safeguarding grapevine biodiversity is one of the main concerns in viticulture today. Management of ex situ collections requires a comprehensive characterization of the conserved germplasm to provide basic material for selection and breeding programs. In this study, the local grapevine germplasm conserved at the national collection of the Lebanese Agricultural Research Institute and composed of 43 accessions was submitted to a genetic and ampelographic study. Nine ISSR primers, previously developed in grapevine, were used in this study. These primers generated a total of 51 bands, of which 77.7% were polymorphic allowing the differentiation of 41 genetic profiles vs. one case of synonymy that was recorded among three accessions. Ampelographic characterization was conducted using a set of 33 descriptors established by the International Office of Vine and Wine and related to leaf, bunch, and berry. Principal component analysis identified 12 descriptors i.e. veraison date, maturity date, berry length, upper and lower vein pigmentation, bunch density, bunch weight, sugar content at harvesting, flesh of juiciness, berry weight, flesh firmness, and color skin, as being the most discriminating descriptors. The correlation between the ISSR clustering and the ampelographic one was not significant (r=0.26) because of the divergence of accessions groups, except for the three accessions synonymy case which was confirmed in both dendrograms. Finally, this comprehensive evaluation of the existing local gene pool of grapevine revealed a substantial diversity. It would further allow the promotion of the valuable accessions directly through multiplication schemes, and their sustainable utilization in genetic improvement programs.

Lebanon has ancient mulberry trees which are the remnants of the abundant orchards that dominated its lands during the nineteenth century. Lebanese mulberry germplasm has not been assessed yet. This study aims to collect local old rainfed mulberry accessions from different geographical regions and assess their diversity by using morphological and molecular markers (SSR and ISSR). Genetic diversity of 70 accessions of mulberry were evaluated by using 27 morphological traits. The dendrogram based on the morphological attributes showed a relative separation of the different accessions based on fruits color and taste. Molecular analysis was performed for the accessions by using selected SSR and ISSR primers. The primers marked a high discriminating power (0.7 to 0.89). The dendrogram constructed on the base of UPGMA method showed 13 different groups. The clustering patterns indicated no location nor local name specificity among mulberry accessions. The combination of SSR and ISSR primers was informative for estimating the extent of mulberry genetic diversity. It can be concluded that there is a high level of genetic diversity within mulberry trees in Lebanon. These results will be useful for mulberry germplasm management in terms of biodiversity protection and as a valuable source of gene pool for crop improvement.

Two Lebanese fig accessions of local varieties (Biadi and Aswad), infected by Fig leaf mottle-associated virus 1 (FLMaV-1), Fig leaf mottle-associated virus 2 (FLMaV-2) and Fig mosaic virus (FMV), were subjected to tissue culture and thermotherapy for producing virus-free plant material. The virus status of all progeny explants was assayed by RT-PCR using viruses-specific primers. The shoot tip culture technique was reliable for elimination of from 60 to 100% of fig viruses. However, stem cutting culture coupled with thermotherapy was the most effective for shoot regeneration (40% of reactive explants), while elimination of the three viruses was possible even though with lower rates of removal (from zero to 81%) were achieved. This study has indicated that FLMaV-2 is more susceptible to thermotherapy than FLMaV-1 and FMV.

Abstract Elimination of Candidatus phytoplasma phoenicium from two infected Lebanese varieties of almond by using different tissue culture techniques is reported. Except for the oxytetracycline therapy which totally inhibited the development of explants, stem cutting cultures associated with thermotherapy, shoot tip cultures associated or not with thermotherapy, and shoot tip micrografting were all suitable, either for shoot regeneration or for elimination of phytoplasma from the two varieties. However, stem cutting culture coupled with thermotherapy seemed to be the most effective for regeneration of phytoplasma-free plantlets. [ABSTRACT FROM AUTHOR]