Root rot and damping-off of Aleppo pine seedlings caused by Pythium spp. in Algerian forest nurseries

Abstract

Aleppo pine (Pinus halepensis Miller) is a common forest tree in the Mediterranean Region. Production of Aleppo pine seedlings is hindered by damping off and root rot diseases in cooler conditions of north-western Algeria, which significantly reduces the seedling emergence. is work was carried out to evaluate the pathogenicity of different Pythium Pringsheim species on Aleppo pine seedlings. Seventeen isolates of Pythium spp. were isolated from diseased seedlings, identified to the species level based on DNA sequence from the internal transcribed spacer region and their identity was confirmed on morphological basis. e obtained isolates were pathologically characterized in Petri dish and pot assays. Germination was significantly inhibited by the different Pythium spp. isolates. e highest inhibition was observed with Pythium ultimum Trow in Petri dish and pot assays. e reduction in root growth differed significantly between different isolates. e maximum reduction in root growth (92.2%) was observed for P. ultimum in Petri dish assay. e various isolates of Pythium showed a significant influence on root length, shoot length and vigour index. e maximum disease incidence (89.7%) was caused by P. ultimum. Our results indicated that Pythium spp. is commonly found on diseased seedlings, in most containers and bare-root nurseries.

Assessment of the Antimicrobial Activity and the Entomocidal Potential of Bacillus thuringiensis Isolates from Algeria

“…Specifically, in Algeria, the most injurious fungus species affecting palms are Fusarium oxysporum, the causal agent of ‘bayoud’, or Fusarium wilt [ 92 , 93 ], and Thielaviopsis paradoxa , the agent of the black scorch disease [ 94 , 95 ]. Different species of the genus Fusarium also affect cereals [ 2 , 96 ], forest trees (Aleppo Pine) [ 97 , 98 ], vegetables [ 99 ], and legumes [ 100 ]. Similar to the antibacterial activity, earlier studies showed that B. thuringiensis isolates were less potent, in terms of antifungal activity, compared to other Bacillus species such as B. amyloliquefaciens and B. subtilis [ 82 , 83 ].…”

DNA-Metabarcoding of Belowground Fungal Communities in Bare-Root Forest Nurseries: Focus on Different Tree Species

“…The oomycetes that were most common in this study ( Table 4 ) are also known to cause seedling diseases in forest nurseries, including taxa such as P. ultimum var. ultimum , P. heterothallicum [ 104 , 105 ] and P. spiculum [ 106 , 107 , 108 ]. Pythium spiculum was previously detected in the feeder roots and in the rhizosphere soil of declining oaks [ 109 ], but information on its pathogenicity to oaks is limited [ 106 ].…”

Checklist of Algerian fungi – Part 2: Chromistan Fungal Analogues (Oomycota, Bigyra, Cercozoa)

“…His results therefore have been published. Only later in the 2010s were published the first contributions of Algerian researchers (most often phytopathologists) reporting the observation of CFA taxa of which some new to Algeria (Corbière et al 2010;Lazreg 2015;Lazreg et al 2013Lazreg et al , 2016Benabdelkader and Ghechi 2013;Benabdelkader et al 2015;Rekad et al 2017;Smahi et al 2017).…”