Study of natural antagonists of potato cyst nematode “Globodera sp.” in west Algeria: Nematological analysis

Potato (Solanum tuberosum) is among the most dominant crops in Algeria. However, it is confronted by many pests like potato cyst nematodes (PCN) Globodera sp. It is among the most important pests that can cause enormous damage and loss of yield each year. This study highlighted morpho-identification and PCN density in 4 different regions of west Algeria, including Tiaret, Saida, Mascara and El Bayadh as well as its association with some microorganisms (bacteria identified by Maldi-TOF-MS method) and fungi (identified by macroscopic and microscopic examinations) that might have biological control activity on PCN. Identification of 8 bacterial isolates by MALDI-TOF-MS technique revealed that 50 % of isolated bacteria belong to the genus Bacillus; B. megaterium for the isolates B15 with a score of 1.994 and B1 with a score of 1.882 and B. cereus for the isolate B20 the score value is 1.892 and 50 % to the genus Pseudomonas with different score values; P1 for a score of 2.294 identify as P. fulva P4 showed a score value of 1.974 to P. corrugata, P2 with a score of 2.148 P. stutzeri and P3 with a score of 2.009, P. kilonensis. Macroscopic and microscopic examination of fungal flora revealed high diversity: 7 orders were isolated, among which the most frequent were Trichocomaceae (30 %) and Pleosporaceae (22 %), while the less frequent were Pythiaceae (5 %) and Davidiellaceae (5 %). The genus Aspergillus recorded a frequency of 59.38 % and the genus Penicillium sp. was detected in 46.88 % of the cyst populations studied.