MYCOLOGIA BALCANICA 2: 205–207 (2005) 205

State of the art in truffl e knowledge and cultivation in

Mattia Bencivenga

Department of Plant Biology and Agricultural and Environmental Biotechnology of the University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy (e-mail: [email protected])

Received 22 September 2004 / Accepted 8 April 2005

Abstract. Th e presence of truffl es in Sicily and perspectives for their cultivation on the island are assessed, with a brief analysis of basic and applied research on truffl es and truffl e cultivation in Italy, focusing on successful production and on reasons for failure in some artifi cial truffl e-beds. Truffl e cultivation has progressed in recent decades and there is now suffi cient know-how for creation of productive truffl e plantations. Further research is needed on host plant growing techniques.

Key words: cultivated truffl e-bed, Italy, truffl es,

Introduction State of the art in basic research in Italy

In recent decades interest in truffl es and truffl e cultivation has In the last twenty years basic and applied research has been increased in Italy and, in particular, in Sicily, where research has oriented to fi ne-tuning and defi nition of cultivation techniques begun aimed at verifying the presence, frequency and ecology for truffl es. Initial research dealt with mycorrhization in of truffl es, and evaluating local cultivation possibilities. host plants and consequent yield results. Th e fi rst artifi cial Th e presence of truffl es in Sicily was demonstrated some mycorrhization was performed in Turin at the Ceruti already years ago (Venturella 1995). Ongoing investigations school (Fontana 1967) obtaining a between have revealed the presence of several species, among which Tuber maculatum Vittad. and Pinus strobus L. at the same the most common (and surely cultivable) are the summer time, Mannozzi-Torini (1970) performed some greenhouse truffl e ( Vittad.) and bianchetto (T. borchii mycorrhization tests on (Quercus pubescens Willd.) with Vittad.). Th e more valued white truffl e (T. magnatum Pico) . In the same period a number of other may also be present in rare and small habitats on mountain mycorrhization tests took place (Palenzona 1969; Fontana slopes, though this has not yet been proved. A search should & Bonfante-Fasolo 1971; Palenzona et al. 1972; Fontana & therefore be undertaken to assess the possible presence of Giovannetti 1979; Palenzona & Fontana 1979), but it was the white truffl e and other valuable species like the black not until the eighties that a revised essay on mycorrhization truffl e (T. melanosporum Vittad.), which may already have techniques was published (Bencivenga 1982). Th at essay been produced in Sicilian cultivated truffl e-beds. Future fostered development of large-scale production of inoculated development of truffl e cultivation will need to observe plants in greenhouses. Research on truffl e mycorrhizal results of research aimed at defi ning the most suitable sites, morphology has made it possible to recognize the mycorrhizae host plants, pre-planting agricultural techniques, host-plant of diff erent species: this is necessary to assess the quality of density and distance, and the best treatment of host plants commercialized inoculated plants (Bencivenga & Granetti during their initial growth and subsequent production phase. 1990; Zambonelli et al. 1993; Bencivenga et al. 1995; 206 bencivenga, m. — state of the art in truffle knowledge and cultivation in italy

Granetti 1995). More recently, to confi rm morphological mistaken agricultural operations. At the same time an increase observations, biomolecular research on mycorrhizae has been in truffl e consumption took place following promotion by conducted (Paolocci et al. 1997, 1999; Rubini et al. 1998, various local agencies. 2004). Studies on morphology have lead to production, in Th is chaotic development of truffl e cultivation brought 1995, of a protocol, commissioned and adopted by various diff erent results: some cultivated truffl e-beds produced a good Italian regions, for assessment and certifi cation of inoculated yield; others had little or no production. Reasons for failure plants: Th e protocol was preceded by a proposal for a method lay in use of: of analysis published by the Italian Ministry of Agriculture a) non-micorrhized host plants; (Bencivenga et al. 1987). Controlled and certifi ed mycorrhized b) unsuitable soils; plants are thus now available. c) incorrect host species or cultivation techniques. Cultivation of such plants supposes knowledge of sites Failures lamented by farmers, and secret successes of some suitable for truffl e production. A search for such sites in fortunate truffl e-growers, resulted between 1999 and 2000 in traditional truffl e growing areas was performed by experts in something of an oblivion for truffl e cultivation. It returned botany and pedology: in particular botanists surveyed plants to in the 2002/2003 season, however, when, thanks present on individual truffl e-beds (the actual spots where to favourable weather conditions most previously under- truffl es are collected) while pedologists dug profi les and took productive artifi cial beds started to yield good quantities of soil samples at various depths. Rainfall and temperature data truffl es. In 2003 demand for truffl e-inoculated plants was were obtained from the recording stations nearest each site. strong, and Italian commercial nurseries were unable to Th e results of such investigations have been published in a provide such high numbers of plants, so that French producers variety of places, and have encouraged improved planting covered the demand. and cultivation techniques for artifi cial truffl e-beds, and development of techniques to regain or improve yield in natural truffl e-beds. Production of cultivated truffl e-beds

Tuber melanosporum Th e present situation in applied research About 80 % of truffl e beds show production of some kind, of these about half provide scarce yields (1-10 kg/ha) Tr u ffl e cultivation in Italy is of ancient origin. Direct while the other half bring satisfactory yields (15-50 kg/ha) cultivation tests were attempted in the 15t and 17t century. with top production rates of more than 100 kg/ha. Francolini (1932), a fore-runner in developing artifi cial mycorrhizal associations, to avoid damage by rodents to young , soaked acorns with ground truffl e, germinating No steady yield; cultivated beds in which suffi cient them in a greenhouse, then transplanting the seedling to conditions of moisture, shade, and soil softness have the fi elds. Truffl e-producing plants were later developed developed, are starting some production. and produced by Mannozzi-Torini, who can be considered the pioneer of Italian truffl e cultivation. With a simple yet Tuber aestivum eff ective technique, he grew young plants of oak (Quercus Tr uffl e beds are in most part still young and unproductive. pubescens) with artifi cially induced mycorrhizae of the black Th e older ones normally bring good yield. T. aestivum is often truffl e (Mannozzi-Torini 1970). produced in beds made up with plants originally inoculated Researchers are now studying the ecological requirements with T. melanosporum. of truffl es authorized for cultivation and marketing in Italy. Th ey are also looking at cultivation techniques for host plants aimed at maintaining and increasing the presence of Tr uffl e beds planted in suitable soils are highly productive. mycorrhizae on roots. Th ough plants with artifi cially induced It must be noted that T. aestivum and T. borchii, once believed mycorrhizal associations were already available in the 1970s, to be adaptable species and suggested as an alternative truffl e cultivation only really spread in the 1980s, mainly for environments not suitable to T. magnatum or to T. due to promotional activities by commercial plant nurseries melanosporum, in reality produce truffl es only in environments which had started producing host plants. Believing that suitable for their own development. truffl e cultivation would be guaranteed with the purchase of guaranteed mycorrhized plants, a great number of truffl e plantations were created in the 1980s and 1990s all over Research projects run at the University of Italy, often with little consideration paid to environmental Perugia conditions of the planting site. In this period, beside commercial nurseries selling host plants, there were also Th e evidence presented above shows that soil and climate unscrupulous dealers promising exaggerated yields, and ill- conditions suitable for cultivation of valuable species of informed technicians recommending a wide range of often truffl e are now known, but there is only little, incomplete mycologia balcanica  () 207 and often empirical experimental data on truffl e-bed References cultivation. In the Department of Plant Biology and Agricultural and Bencivenga, M. 1982. Alcune metodiche di micorrizazione di piante forestali Environmental Biotechnology of the University of Perugia, con il tartufo nero pregiato di Norcia o di Spoleto (Tuber melanosporum following an agreement with the local government of Regione Vitt.). – L’informatore Agrario 38(21): 21155-21163. , some experimental projects have been started on Bencivenga, M. & Granetti, B. 1990. Valutazione biometrica delle micorrize artifi cial truffl e-beds created by regional public agencies. di Ostrya carpinifolia Scop. prodotte da tartufi di varie specie. – In: In productive beds, projects are aimed at increasing yield Comunità Montana dei Monti Martani e del Serano, Spoleto [ed.]. Atti del through testing application of diff erent levels of irrigation (in II Congresso Internazionale sul Tartufo, Spoleto, 24-27 Novembre 1988. terms of quantity of water supplied and irrigation scheduling), Pp. 141-154. Spoleto. diff erent tilling methods and various combinations of tillage Bencivenga, M., Ferrara, A.M., Fontana, A., Granetti, B., Gregori, G., Lo Bue, G., and irrigation. Palenzona, M., Rebaudengo, E., Tocci, A. & Zambonelli, A. 1987. Valutazione In non-productive beds, which are already ten years old, del lo stato di micorrizazione in piante tartufi gene. Proposta di un metodo. Minis- reasons for lack of production are investigated, with attempts tero dell’Agricoltura e delle Foreste, Corpo Forestale dello Stato, Roma. to remove the causes of each failure. Tests include organic Bencivenga, M., Di Massimo, G., Donnini, D. & Tanfulli, M. 1995. Micorrize fertilization and/or soil nutrient correction, surface tilling, inquinanti frequenti nelle piante tartufi gene – Nota I – Inquinanti in Vivaio. diff erent types of pruning on host plants and inoculation – Micologia Italiana 24(2): 185-207. of truffl e in the soil. Th ere are also artifi cial truffl e- Fontana, A. 1967. Sintesi micorrizica tra Pinus strobus e Tuber maculatum. beds which showed production for some years but later – Giornale Botanico Italiano 101: 298-299. ceased producing with no apparent reason. Th is is a new and Fontana, A. & Bonfante-Fasolo, P. 1971. Sintesi micorrizica di Tuber brumale serious problem being addressed through investigation of Vitt. con Pinus nigra Arnold. – Allionia 17: 15-18. the condition of the truffl e-bed (soil, host plant, mycorrhizal Fontana, A. & Giovannetti, G. 1979. Simbiosi micorrizica fra incanus status) to establish techniques which could help production L. ssp. incanus e Tuber melanosporum Vitt. – Allionia 23[1978]: 5-11. recover. In most cases a decrease in the level of mycorrhizae Francolini, F. 1931. Tartufi coltura e rimboschimenti. Federazione italiana dei is observed in host plant roots, and basic treatment consists consorzi agrari. Ed. Piacenza, Piacenza. of inoculation with truffl e spores, combined with various Granetti, B. 1995. Caratteristiche morfologiche, biometriche e strutturali pruning, tilling, and irrigation activities. delle micorrize di Tuber di interesse economico. – Micologia Italiana 2: 101-117. Mannozzi-Torini, L. 1970. Manuale di tartufi coltura. Edagricole, Bologna. Conclusions Palenzona, M. 1969. Sintesi micorrizica tra Tuber aestivum, T. brumale, T. melanosporum e semenzali di Corylus avellana. – Allionia 15: 121-131. Tr u ffl e cultivation in the last thirty years has greatly progressed, Palenzona, M. & Fontana, A. 1979. Synthèse des mycorhizes de Tuber establishing itself as a real form of agriculture, suffi ciently safe magnatum Pico avec semis de Quercus pubescens Willd. – Science and profi table. 10: 1007-1012. However, there is still a lot to do to step from “suffi cient” Palenzona, M., Chevalier, G. & Fontana, A. 1972. Sintesi micorrizica tra i to completely safe. Th e weak point of present-day truffl e miceli in coltura di T. brumale, T. melanosporum, T. rufum e semenzali di cultivation is the poor understanding of those cultivation conifere e latifoglie. – Allionia 18: 41-52. techniques for host plants necessary for mycorrhizal Paolocci, F., Rubini, A., Granetti, B. & Arcioni, S. 1997. Typing Tuber conservation in roots and production of carpophores. melanosporum and Chinese black truffl e species by molecular markers. Research on these topics is long and diffi cult, but is the only – FEMS Microbiology Letters 153: 255-260. way to provide growers with the good advice on cultivation Paolocci, F., Rubini, A., Granetti, B. & Arcioni, S. 1999. Rapid molecular techniques which they so often request, and which almost approach for a reliable of Tuber spp. ectomycorrhizae. – FEMS Microbiology as often to date cannot be given. One clear need is the Ecology 28: 23-30. establishment and training of a group of expert agricultural Rubini, A., Paolocci, F., Granetti, B. & Arcioni, S. 1998. Single step molecular technicians which could support truffl e growers in constant characterization of morphologically similar black truffl e species. – FEMS link with research centers. Microbiology Letters 164: 7-12. Rubini, A., Topini, F., Riccioni, C., Paolocci, F. & Arcioni, S. 2004. Isolation and characterization of polymorphic microsatellite loci in white truffl e (Tuber magnatum). – Molecular Ecology Notes 4(1): 116-118. Venturella, G. 1995. Stato attuale delle conoscenze del genere Tuber P. Micheli ex Wiggers in Sicilia. – In: F. Corbetta, G. Pacioni, F. Tammaro & L. Marra [eds]. Atti del Convegno “Funghi, Tartufi ed Erbe mangerecce”, L’Aquila, 28 Settembre – 1Ottobre 1995. Pp. 1-6. L’Aquila. Zambonelli, A., Salomoni, S. & Pisi, A. 1993. Caratterizzazione anatomo- morfologica delle micorrize di Tuber spp. su Quercus pubescens Willd. – Micologia Italiana 3: 73-87.