ABSTRACT
The phylogenetic relationships among Tirmania were investigated using the internal transcribed spacer (ITS) and large subunit (LSU) regions of the nuclear-encoded ribosomal DNA (rDNA) and compared with morphological and bioclimatic data. The combined analyses of forty-one Tirmania samples from Algeria and Spain supported four lineages corresponding to four morphological species. Besides the two previously described taxa, Tirmania pinoyi and Tirmania nivea, here we describe and illustrate a new species, Tirmania sahariensis sp. nov., which differs from all other Tirmania by its distinct phylogenetic position and its specific combination of morphological features. We also present a first record of Tirmania honrubiae from North Africa (Algeria). Our findings suggest that restrictions imposed by the bioclimatic niche have played a key role in driving the speciation process of Tirmania along the Mediterranean and Middle East.
ABSTRACT
The present study aimed to highlight the insecticidal activity of the Algerian desert truffle Terfezia claveryi Chatin against two post-harvest pests of rice and other cereal products, the rice weevil Sitophilus oryzae (L.), and the lesser grain borer Rhyzopertha dominica (F.), using direct contact application method with the filter paper impregnation technique. Soxhlet apparatus was used for extraction with chloroform as solvent. The major compounds in chloroform extract of T. claveryi were identified using gas chromatography-mass spectrometry (GC-MS). The two-way ANOVA was used for statistical analysis to determine the exposure time and doses with the greatest insecticidal activity. Findings of this study revealed that the major compounds were fatty acids: linoleic acid, methyl ester (14.84%), 11,14-eicosadienoic acid, methyl ester (11.55%), oleic acid, methyl ester (7.1%), and palmitic acid (6.96%). However, chamazulene (0.88%) was found to be minor compound. Our results describe for the first time the presence of chamazulene in desert truffle. The result showed also that the most potent insecticidal activity of chloroform extract of T. claveryi was found towards S. oryzea with LD50 value of 162.11 µg/mL. For concentrations of 250 and 300 µg/mL, this extract was able to eradicate 96.65 ± 1.15% and 100.0 ± 0.0% of S. oryzea after 24 h of exposure. However, it caused only 47.24 ± 1.15% and 50.66 ± 1.15% of mortality of R. dominica, respectively, after 6 days. This work offers promising prospects for the use of desert truffles extracts as a potential insecticidal agent for improving quality and safety of stored foods against damage caused by stored-product pests.
