In vitro shoot-tip grafting improves recovery of cotton plants from culture

A rapid in vitro shoot-tip grafting (STG) technique was adapted to increase recovery of intact cotton plants from shoots developed in culture. Inducti on of root organogenesis in cotton shoots is genotype dependent and unrelia ble. The resulting loss of regeneration potential due to failure to form ro ots can vary from 30 to 80% according to genotype and represents a signific ant bottleneck in the overall recovery of plants from culture. If the non-r ooting shoots are transgenic, the loss in regenerated plant material can be substantial. In vitro grafting of cotton shoots to seedling rootstock prov ed to be a simple and reliable method allowing 90-100% recovery of non-root ing shoots from culture. Success of any given graft was directly related to scion size (0.8-1.0 cm) and age (14-35 days) of the seedling rootstock. Th e method appeared to be genotype independent, and varietal differences betw een rootstock and scion did not effect the race of plant recovery from cult ure.