Inoculation of seven pine species or hybrid seedlings with Korean isolates of pinewood nematode under greenhouse conditions

Abstract

Abstract• Seedlings of seven pine species or hybrids, Pinus densiflora, Pinus thunbergii, Pinus virginiana, Pinus echinata, Pinus koraiensis, Pinus thunbergii × Pinus massoniana and Pinus × rigitaeda, were inoculated in a greenhouse with 100, 1 000 and 10 000 pathogenic nematodes, Bursaphelenchus xylophilus, to compare initial symptom development and to evaluate susceptibility to pinewood nematodes.• Genetic types were significantly different in the starting day of needle discoloration (χ 2 = 43.48; P < 0.001) and the period from nematode inoculation to seedling death (χ 2 = 32.85; P < 0.001), but treatment groups were not statistically different in the days from inoculation to seedling death in any of the pine species.• There was no relationship between seedling mortality and the number of nematodes recovered from infected seedlings. Only eight of the nematode-inoculated seedlings remained alive by day 83 after inoculation, including four seedlings each of P. echinata and P. × rigitaeda grown from bulked seed collections.• Seedlings from the bulk lots were likely more genetically diverse than those from the single-source lots. A broader genetic representation of pine species or hybrids is suggested for screening for planting stocks resistant to B. xylophilus. Mots-clés :nématode du pin / sensibilité / inoculation / Bursaphelenchus xylophilus / mortalité Résumé -Inoculation sous serre de semis de sept espèces ou hybrides de pin par des isolats coréens du nématode du pin.• Des semis de sept espèces ou hybrides de pin, Pinus densiflora, Pinus thunbergii, Pinus virginiana, Pinus echinata, Pinus koraiensis, Pinus thunbergii × massoniana, et Pinus × rigitaeda ont été inoculés sous serre par 100, 1000 ou 10 000 nématodes pathogènes Bursaphelenchus xylophilus, pour comparer le développement des symptômes à leur début et évaluer la sensibilité de ces essences.• Des différences significatives ont été trouvées entre types génétiques pour la date de début de déco-loration des aiguilles (χ 2 = 43.48 ; P < 0.0001), ainsi que pour le délai entre l'inoculation et la mort des plants (χ 2 = 32.85 ; P < 0.0001), mais pas entre traitements, quelle que soit l'espèce.• Aucune relation n'a été observée entre la mortalité des semis et le nombre de nématodes récupérés des semis infestés. Seulement huit plants inoculés étaient encore vivants après 83 jours, dont quatre de P. echinata et de P. × rigitaeda issus des collections de graines en vrac.• Les semis des lots de vrac étaient probablement génétiquement plus variés que ceux des lots de source unique. Une plus large représentation des espèces et des hybrides serait nécessaire pour un screening des souches de plantations résistantes à B. xylophilus.

Intraspecific variation of anatomical and chemical defensive traits in Maritime pine (Pinus pinaster) as factors in susceptibility to the pinewood nematode (Bursaphelenchus xylophilus)

“…The PWN affects several pine species differently, with P. densiflora and P. pinaster being extremely susceptible and P. taeda, P. strobus and P. pinea highly resistant (Dwinell 1984;Woo et al 2008;Dayi and Akbulut 2012). Variation of resistance within pine species to the PWN has been also reported in some previous studies (Kuroda 2004;Franco et al 2011;Akiba et al 2012), and prompted the launch of different breeding initiatives aimed to provide resistant genetic material to be used in areas of high risk of PWN damage (Toda and Kurinobu 2002;Nose and Shiraishi 2008;Ribeiro et al 2012).…”

Resistencia de Pinus pinaster Ait. al marchitamiento del pino causado por Bursaphelenchus xylophilus (Steiner & Burher), Nickle

“…et Zucc. (Mamiya, 1983;Woo et al, 2008). Pinus pinaster y P. radiata se clasificaron como susceptibles, si bien las tasas de mortalidad en algunos estudios difieren ligeramente de las obtenidas en este trabajo (Daub, 2008;.…”

Differential Impact of the Pinewood Nematode on Pinus Species Under Drought Conditions

“…For tree inoculation, a wound was made on the main stem of each plant by removing an area of bark (2 cm × 1 cm), and a piece of cotton was placed in the wound. Then, the nematode suspension, already adjusted with sterilized water to achieve a concentration of 6,000 (mixed developmental stages)/100 μL, or sterilized water was pipetted onto the cotton and covered with parafilm to prevent desiccation ( Woo et al, 2008 ; Yazaki et al, 2018 ).…”