OVERCOMING CROSSING BARRIERS BETWEEN CASSAVA, MANIHOT-ESCULENTA CRANTZ AND A WILD RELATIVE, M-POHLII WARWA

The use of mentor pollen has enabled successful hybridization between cassava, Manihot esculenta Crantz, and the wild species M. pohlii Warw a. Killed pollen of a cross compatible type produced by freeze-thawing was mixed with incompatible pollen and the mixes were dusted on stigm as. This treatment resulted in production of seed in 4.9% of the total pollinations, compared to 0% in the case of untreated pollinations. T he use of a bridge species, M. neusana Nassar, through the hybrid M. p ohlii and M. neusana also proved successful in overcoming interspecifi c barriers between cassava and M. pohlii.