Pseudomonas isolates have frequently been isolated from the rhizosphere of plants, and several of them have been reported as plant growth-promoting rhizobacteria. In the present work, tomato ( Solanum lycopersicum ) seeds were germinated in greenhouse conditions, and the seedling height, length of plants, collar diameter and number of leaves were measured from plants grown in soil inoculated by bacterial isolates. Pseudomonas isolates were isolated from the rhizosphere. We used the Newman-Keuls test to ascertain pairwise differences. Isolates were identified as a new Pseudomonas species by rpo D gene sequencing. The results showed that isolates of Pseudomonas sp. (Q6B) increased seed germination (P = 0.01); Pseudomonas sp. (Q6B, Q14B, Q7B, Q1B and Q13B) also promoted seedling height (P = 0.01). All five isolates promoted plant length and enlarged the collar diameter (P = 0.01). Pseudomonas sp. (Q1B) also increased leaf number (P = 0.01). The investigation found that Pseudomonas isolates were able to solubilize phosphate, produce siderophores, ammonia, and indole-3-acetic acid and colonize the roots of tomato plants. This study shows that these five novel Pseudomonas sp. isolates can be effective new plant growth-promoting rhizobacteria.

No abstract

No abstract

The increasing demand for new bioactive compounds to combat the evolution of multi-drug resistance (MDR) requires research on microorganisms in different environments in order to identify new potent molecules. In this study, initial screening regarding the antimicrobial activity of 44 Actinomycetes isolates isolated from three soil samples from three different extremely cold sites in Morocco was carried out. Primary and secondary screening were performed against Candida albicans ATCC 60,193, Escherichia coli ATCC 25,922, Staphylococcus aureus ATCC 25,923, Bacillus cereus ATCC 14,579, other clinical MDR bacteria, and thirteen phytopathogenic fungi. Based on the results obtained, 11 active isolates were selected for further study. The 11microbial isolates were identified based on morphological and biochemical characters and their molecular identification was performed using 16S rRNA sequence homology. The UV–visible analysis of dichloromethane extracts of the five Streptomyces sp. Strains that showed high antimicrobial and antioxidant (ABTS 35.8% and DPPH 25.6%) activities revealed the absence of polyene molecules. GC–MS analysis of the dichloromethane extract of E23-4 as the most active strain revealed the presence of 21 volatile compounds including Pyrrolopyrazine (98%) and Benzeneacetic acid (90%). In conclusion, we studied the isolation of new Streptomyces strains to produce new compounds with antimicrobial and antioxidant activities in a cold and microbiologically unexplored region of Morocco. Furthermore, this study has demonstrated a significant (P < 0.0001) positive correlation between total phenolic and flavonoid contents and antioxidant capacity, paving the way for the further characterization of these Streptomyces sp. isolates for their optimal use for anticancer, antioxidant, and antimicrobial purposes.

Dactylopius opuntiae is an insect pest of cactus which is currently causing severe damage to cactus crops in Morocco. It was first observed in 2014 in the Sidi Bennour region 120 km northwest of Marrakech, and has spread very quickly to destroy the prickly pear cactus crops (Opuntia ficus‐indica (L.) Miller) in several regions of country, causing very heavy economic losses. To control this pest, the predatory potential of eleven species of native Moroccan ladybird predators was investigated under laboratory conditions at 26 ± 2°C, 60 ± 10% RH and a 12 h light:12 h dark regime. The experiments were conducted in no‐choice feeding tests (only eggs, first instar or second instar of mealybugs were offered at one time) and free‐choice feeding tests (eggs and first and second instar larvae were offered simultaneously). In the no‐choice feeding tests, Exochomus nigripennis, Chilocorus bipustulatus and Chilocorus politus consumed the highest mean number of mealybug eggs and first instars, and the highest mean number of second instars was consumed by Hippodamia convergens. In the free‐choice feeding tests the highest mean number of mealybug eggs was eaten by Chilocorus bipustulatus and Chilocorus politus and Hippodamia convergens consumed the highest mean number of first and second instars of the mealybug.