BIODIVERSITY OF EPICHLOË ENDOPHYTES OF A NATIVE FORAGE GRASS FROM ARGENTINA AND DETECTION OF ALKALOID BIOSYNTHESIS GENES.

IANNONE L.J, PINGET A.D., ROSSI M.S., DE BATTISTA J., YOUNG C., SCHARDL C.L

Buenos Aires

Congreso; THE 6th INTERNATIONAL SYMPOSIUM ON THE MOLECULAR BREEDING OF FORAGE AND TURF; 2010

Epichloë endophytes have been employed in plant breeding programs because of the beneficial effects these fungi have on plant growth and resistance to herbivores. The knowledge of the diversity of symbioses between native grasses and endophytes and their potential to produce different alkaloids is crucial for using these symbioses in grass breeding programs. In this work we characterize the epichloë endophytes of Bromus auleticus, a promising forage grass from South-America. Phylogenetic studies based on tubB and tefA genes revealed that plants from different regions are associated with different endophytes, N. tembladerae and the new species N. pampeanum. Plants infected with N. pampeanum or N. tembladerae produce more biomass than their endophyte free counterparts. Diagnostic PCR to screen for some of the genes involved in the biosynthetic pathways for ergot alkaloids, lolines and lolitrem were performed. Isolates of both species lack the dmaW gene, thus these endophyte should not produce ergot alkaloids.  Neotyphodium tembladerae isolates were negative for lolC and positive for some ltm genes from clusters 1 and 2. and thus incapable to produce lolines but likely to be capable of producing lolitrem precursors such as paxilline and possibly terpendoles.  Neotyphodium pampeanum isolates were positive for lolC gene and negative for ltm genes from cluters 1, 2 and 3 and thus, likely capable of producing lolines but incapable of producing lolitrems or the indole-diterpene precursors. These results show the importance of the endophytes on the performance of B. auleticus and suggest the symbiosis between B. auleticus and N. pampeanum as a promising improvement for this forage grass.