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

Abstract

A rapid in vitro shoot-tip grafting (STG) technique was adapted to increase recovery of intact cotton plants from shoots developed in culture. Induction of root organogenesis in cotton shoots is genotype dependent and unreliable. The resulting loss of regeneration potential due to failure to form roots can vary from 30 to 80% according to genotype and represents a significant bottleneck in the overall recovery of plants from culture. If the non-rooting shoots are transgenic, the loss in regenerated plant material can be substantial. In vitro grafting of cotton shoots to seedling rootstock proved to be a simple and reliable method allowing 90–100% recovery of non-rooting 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. The method appeared to be genotype independent, and varietal differences between rootstock and scion did not effect the rate of plant recovery from culture.