Bonjour à tous,
Dans mes prélèvements de racines aesti/unci je retrouve ce qui s'apparente à Scleroderme.
Je suis toujours à la recherche d'un document style clé d'identification du mycélium et mycorhizes de Scleroderme.
Mais j'ai trouvé une publi intéressante qui parle de l'effet négatif de la mycorhization aestivum sur l'hôte. Que l'on ne retrouve pas lorsque Scleroderme est présent également. Ainsi qu'une description sur la stratégie de développement/colonisation rapide de Scléro en tant que basidio par rapport au développement plus lent d'aestivum ascomycète. Et enfin un caractère non "antagoniste" entre Scléro et melano d'un auteur qui pourrait peut-être être extrapolé pour aestivum également.
Publi: Mycorrhizal colonization by Tuber aestivum has a negative effect on the vitality of oak and hazel seedlings
"In the present study, a balancing effect of Scleroderma mycorrhization was observed. This could be explained by
the differentiation between the physiology of Scleroderma sp. and Tuber aestivum. Scleroderma spp. mycelium is a fast growing one in contrast to T. aestivum. The mycorrhiza of Scleroderma spp. is a long distance exploration type in contrast to the short distance exploration type that of T. aestivum (Agerer 2001,
www.deemy.de). Additionally, mycorrhiza of the two species has evolved in two different ways. According the genome of Tuber melanosporum (Martin et al. 2010) and Laccaria bicolor (Martin et al. 2008), ascomycetes and basidiomycetes have different ‘symbiosis toolbox’. Ragnelli et al. (2013) showed programmed cell death in plant roots caused by ECM of Tuber spp., which could ascribe to their degrading enzymes. On one hand, the faster grow of mycelia of Scleroderma sp. can cause a faster colonization of the host plant, thus if Scleroderma sp. colonization has a negative effect this process could have elapsed and the mycorrhizal relationship may turns to beneficial. Because of the slower mycelia growth of summer truffle it may develop mycorrhiza only when Scleroderma sp. is already in its beneficial stage, so the negative effect of summer truffle could be faded by Scleroderma spp. On the other hand, exploration types can utilize different nitrogen sources (Hobbie and Agerer 2009), therefore different effects of the colonization rates and nitrogen metabolism may also affect the vitality of the host plant. The common occurrence of T. aestivum and Scleroderma spp. on Hungarian natural sites have been observed by truffle collectors, that is in dried years Scleroderma spp. produces fruit bodies, while in wet years T. aestivum has a bigger amount of yield. Furthermore, in the case of T. melanosporum, Scleroderma verrucosum seems to have neutral effect on truffle orchards (Sourzat 2011). Despite the negative effect of T. aestivum, the values of maximal quantum efficiency of PSII centres ranged between 0.78 and 0.83 which can be qualified as a non-stressed condition (Baker 2008)"
Ça va dans le même sens que la réflexion de certains membres du forum. Si ils n'ont pas été influencé par cette publi, ça va dans leur sens.
Il y a quelques infos pour Sleroderme sur le site cité dans l'étude:
http://www.deemy.de/
https://link.springer.com/article/10.10 ... 016-0748-6
https://www.dgfm-ev.de/publikationen/ar ... m/download