Search

Ectomycorrhizal fungi (EMF) in Lactarius sect. Deliciosi produce valuable edible mushrooms. Market supplies are harvested from natural populations. Sustainable cultivation could increase commercial crop production. The first step in EMF cultivation is the production of host seedlings well colonised by the target species. The aim of this study was to compare the efficiency of vegetative versus spore inoculum for controlled mycorrhizal synthesis between Lactarius and Pinus species native to China. Inoculated seedlings were incubated in a glasshouse for up to 14 months. Mycorrhizae were synthesised, using vegetative inoculum, for 13 distinct combinations of five Pinus and five Lactarius species, 12 of these unprecedented. Spore inoculation was not successful. The successful mycorrhization presented here provides a foundation for establishing mushroom orchards, with L. deliciosus x P. yunnanensis or P. radiata, L. hatsudake x P. yunnanensis or P. tabuliformis, and L. vividus x P. massoniana or P. radiata appearing as promising symbionts for cultivation. Beginning 5 months following inoculation, mycorrhizal seedlings underwent extensive insect grazing. Adult forms of Bradysia impatiens were the most frequent insects caught on sticky traps, while their larvae were observed foraging through roots. The control of insects in the nursery will be critical to large-scale production of mycorrhizal seedlings. Key words: Lactarius section Deliciosi, Pinus, mycorrhizal synthesis, insect damage, Bradysia impatiens. Lactarius sect. Deliciosi regroupe des champignons ectomycorhiziens (CEM) qui produisent des champignons comestibles de valeur. Le marche est approvisionne par des champignons recoltes parmi les populations naturelles. L'exploitation durable pourrait accroitre la production commerciale. La premiere etape dans la culture des CEM est la production de semis de l'hote adequatement colonises par l'espece de champignon desiree. L'objectif de cette etude consistait a comparer l'efficacite de l'inoculum vegetatif versus les spores pour obtenir la synthese mycorhizienne controlee entre des especes de Lactarius et de Pinus indigenes en Chine. Les semis inocules ont ete incubes jusqu'a 14 mois en serre. Les mycorhizes ont ete synthetisees a l'aide d'inoculum vegetatif dans le cas de 13 combinaisons differentes impliquant cinq especes de Pinus et cinq especes de Lactarius, dont 12 etaient sans precedent. L'inoculation avec des spores n'a pas fonctionne. Les syntheses mycorhiziennes presentees ici fournissent les bases pour etablir des vergers de champignons avec L. deliciosus x P. yunnanensis ou P. radiata, L. hatsudake x P. yunnanensis ou P. tabuliformis et L. vividus x P. massoniana ou P. radiata qui semblent etre des symbiotes prometteurs pour la culture. A partir de cinq mois suivant l'inoculation, les semis mycorhizes ont subi un important broutage par les insectes. Les stades adultes de Bradysia impatiens sont les insectes les plus frequemment captures dans des pieges englues, tandis que leurs larves ont ete observees en train de s'alimenter au niveau des racines. La maitrise des insectes en pepiniere sera essentielle pour produire des semis mycorhizes a grande echelle. [Traduit par la Redaction] Mots-cles : Lactarius sect. Deliciosi, Pinus, synthese mycorhizienne, dommage cause par les insectes, Bradysia impatiens., Introduction Forest mushrooms that belong to Lactarius section Deliciosi (Fr.: Fr.) Redeuilh, Verbeken & Walleyn are harvested worldwide for food and income. These fungi live in mycorrhizal symbiosis with a [...]

In animal cells, inhibition of non-homologous end joining (NHEJ) pathway improves the efficiency of homologous recombination (HR)-mediated double-strand brakes (DSBs) repair. To improve the efficiency of HR in sheep embryo fibroblasts, the NHEJ key molecule DNA ligase 4 (Lig4) was suppressed by siRNA interference. Four pairs of siRNA targeting Lig4 were designed and chemically synthesized. These siRNA were electro-transferred into sheep embryo fibroblasts respectively. Compared with the control groups, two pairs of siRNA were identified to effectively inhibit the expression of sheep Lig4 gene by qRT-PCR and Western blotting. The plasmid rejoining assay was adopted for examining the efficiency of HR-mediated DSB repair. I-SceⅠ endonuclease linearized vector and siRNA were co-transfected into sheep embryo fibroblasts. Flow cytometry analysis of cells after transfection for 72 h showed that suppression of Lig4 using siRNAs increased the rejoining efficiency of HR vector by 3-4 times compared with the control groups. Therefore, enhanced HR vector rejoining frequency by instant inhabition of Lig4 gene provides theoretical basis for improving gene targeting efficiency of sheep embryo fibroblasts.