Intraspecific variability of Pythium myriotylum isolated from cocoyam and other host crops.

Intraspecific variability within 51 isolates of Pythium myriotylum from cocoyam (Xanthosoma sagittifolium) and other host crops was analysed using optimum growth temperature, esterase banding patterns, AFLPs, rDNA-ITS sequencing, and virulence to cocoyam. P. myriotylum isolates virulent to cocoyam could easily be differentiated from other isolates of P.

Root induction in Pinus ayacahuite by co-culture with Agrobacterium tumefaciens strains.

Transformation of in-vitro-derived shoots of Pinus ayacahuite Ehrenb. was achieved by co-culture with an oncogenic strain (A281 x 200) of Agrobacterium tumefaciens. During co-culture rooting also occurred; however, this rooting was not induced by genetic transformation of host cells, because a "disarmed" strain of A.