Monitoring the fate of a 30-year-old truffle orchard in Burgundy: from Tuber melanosporum to Tuber aestivum     

Virginie Molinier  Marie-Lara Bouffaud  Thierry Castel  Arnaud Mounier  Annie Colombet  Ghislaine Recorbet  Henri Frochot  Daniel Wipf 《Agroforestry Systems》2013,87(6):1439-1449

Truffles, i.e. tree root-associated fungal fruiting bodies, clearly range among the world’s most exclusive delicacies. Despite the quite restricted natural geographic occurrence of one of the most renowned fungal species, namely Tuber melanosporum, the development of inoculation procedures in the late 1960s made it possible to enlarge its production area in different countries. This was achieved by planting orchards with host tree seedlings colonized by the fungus. In the present work, we investigate the behavior of one of the earliest T. melanosporum orchards planted in Burgundy (France) over a long-term scale (more than 30 years). A picture of the orchard evolution was obtained by recording truffle yields and fungal morphotypes over the seasons and relating them to host-tree development and climate data. The most relevant results include the time-delayed, but rather fast replacement of inoculated T. melanosporum by naturally occurring T. aestivum and the key role of climate in the inter-annual variability of truffle production.  相似文献   

Development of a real-time PCR method to quantify the PGPR strain Azospirillum lipoferum CRT1 on maize seedlings     

Olivier Couillerot  Marie-Lara Bouffaud  Ezékiel Baudoin  Daniel Muller  Jesus Caballero-Mellado 《Soil biology & biochemistry》2010,42(12):2298-2305

Azospirillum lipoferum CRT1 is a promising phytostimulatory PGPR for maize, whose effect on the plant is cell density-dependent. A nested PCR method is available for detection of the strain but does not allow quantification. The objective was to develop a real-time PCR method for quantification of A. lipoferum CRT1 in the rhizosphere of maize seedlings. Primers were designed based on a strain-specific RFLP marker, and their specificity was verified under qualitative and quantitative PCR conditions based on successful CRT1 amplification and absence of cross-reaction with genomic DNA from various rhizosphere strains. Real-time PCR conditions were then optimized using DNA from inoculated or non-inoculated maize rhizosphere samples. The detection limit was 60 fg DNA (corresponding to 19 cells) with pure cultures and 4 × 10⁴ CFU equivalents g⁻¹ lyophilized sample consisting of mixture of rhizosphere soil and roots. Inoculant quantification was effective down to 10⁴ CFU equivalents g⁻¹. Assessment of CRT1 rhizosphere levels in a field trial was in accordance with estimates from semi-quantitative PCR targeting another locus. This real-time PCR method, which is now available for direct rhizosphere monitoring of A. lipoferum CRT1 in greenhouse and field experiments, could be used as a reference for developing quantification tools for other Azospirillum inoculants.  相似文献