Effects of ectomycorrhizal inoculation and the type of substrate on mycorrhization, growth and nutrition of containerised Pinus pinea L. seedlings produced in a commercial nursery

Abstract

-Spore inocula of Melanogaster ambiguus (Vittad.) Tul. & C. Tul., Pisolithus tinctorius (Pers.) Coker & Couch, Rhizopogon luteolus Fr., Rhizopogon roseolus (Corda) Th. M. Fr. and Scleroderma verrucosum (Bull.) Pers., and two substrates (a mixture of peat-vermiculite and a mixture of peat-composted pine bark) were evaluated for producing mycorrhizal Pinus pinea L. seedlings in a commercial nursery in NE Spain. Inocula of all fungi were effective to obtain containerised mycorrhizal P. pinea seedlings although seedling mycorrhization rates were reduced in the peat/pine-bark mixture. Neither inoculation nor the type of substrate modified the first-year growth of seedlings. Rhizopogon spp. increased the levels of N and P and, in general inoculation reduced the concentration of Mn in needles. Symptoms of chlorosis were detected in all seedlings growing in the peat/pine-bark mixture, probably due to nutritional deficiencies caused by the substrate high pH. Among the fungi tested, R. roseolus is proposed as the best candidate for its application in nursery inoculation programmes destined to produced containerised mycorrhizal P. pinea. , et deux substrats (un mélange de tourbe-vermiculite et un mélange de tourbe-écorce compostée de pin) ont été évalués pour produire des jeunes plants mycorhizés de Pinus pinea L. dans une pépinière commerciale au Nord-Est de l'Espagne. Les inoculums de tous les champignons ont été efficaces pour obtenir des semis mycorhizés de pin pignon en conteneur, bien que les taux de mycorhization ont diminué dans le substrat vermiculite-écorce de pin. Ni l'inoculation ni le type de substrat n'ont modifié la croissance en première année des jeunes plants. Les espèces de Rhizopogon ont augmenté les niveaux d'azote et de phosphore dans les aiguilles des plants et, en général, l'inoculation a réduit la teneur en manganèse de ces feuilles. Des symptômes de chlorose ont été détectés dans tous les plants croissant dans le substrat vermiculiteécorce de pin, probablement en raison des carences nutritionnelles provoquées par le pH élevé du substrat. Parmi les champignons étudiés, on propose R. roseolus comme le meilleur candidat pour son application dans des programmes d'inoculation en pépinière destinés à produire des plants de pin pignon mycorhizés en conteneur.Pinus pinea / substrat / mycorhization / champignons ectomycorhiziens / production des semis en pépinière

Mycorrhization, growth and nutrition of Pinus halepensis seedlings fertilized with different doses and sources of nitrogen

“…P. tinctorius has been widely used for inoculating several conifer species in nurseries with varying success rates (Brundrett et al, 1996;Marx, 1981;Rincón et al, 2005). The effectiveness of fungus L. deliciosus was only around 50%, which is in line with other previous reports for this fungus (Gonzalez-Ochoa et al, 2003;Parladé et al, 2003).…”

“…Negative inoculation x fertilization interactions were found, so mycorrhizal effects appeared only at low fertilization, whereas high fertilization eliminated these effects. Interactive effects between fertilization and mycorrhization are frequent (Hilszanska et al, 2008;Parladé et al, 2003;Rincón et al, 2005;2007b;Smith and Read, 1997) and are attributed to the large amount of carbohydrates that the fungus requires to establish symbiosis (Dosskey et al, 1991). This justifies the detrimental effects of the mycorrhiza observed, particularly on the P. tinctorius 3SR strain which reached the highest root colonization levels.…”

Influence de la méthode de fertilisation sur la mycorhization contrôlée de deux espèces de Pins méditerranéens

“…Voucher dry basidiomata and pure cultures were deposited in the herbarium and culture collection of DPV-IRTA (Barcelona, Spain). Miceliar inocula of L. laccata and P. tinctorius and spore inocula of P. tinctorius and M. ambiguus were obtained as previously described [33,34].…”

“…Obtaining a well-developed root system of seedlings in nursery is important since a vigorous root growth contributes to the ability of seedlings to overcome post transplanting stress [15]. Mycorrhization can be an important advantage for seedlings to surmount transplanting stress [7,36] especially under unfavourable field conditions such as those imposed by the Mediterranean climate [25,34]. When nursery production of mycorrhizal plants is desired, an adjustment of the fertilisation regime becomes essential, since high fertilisation inputs usually inhibit the formation of ectomycorrhizas [4,14,35].…”

Arbuscular mycorrhizal colonization of vascular plants from the Yungas forests, Argentina

“…The success of any ecosystem's reforestation effort is, therefore, likely to depend on the establishment of mycorrhizas [29,46,55,69,71]. Unfortunately, at present indigenous trees in the Yungas ecosystem are not being used for reforestation purposes.…”