The mechanism of graft incompatibility is not yet fully understood and many reports focus on this problem in order to understand the mechanisms of graft development. Graft incompatibility is reported due to the Structural or Anatomical reasons, physiological and biochemical reasons, nutritional deficiency and presence of viruses at an early phase in response to grafting, as well as the consequences of these events on the future graft response. All these abnormalities result in mechanical weakening of the union, which may manifest the first year after grafting or may appear several years later, leading to major economic losses. Successful union of stock/scion involves lining up of vascular cambiums, subsequent wound healing response, callus bridge formation, wound repair xylem and phloem occur in the callus bridge just prior to initial cambium formation, the vascular cambium is completed across the callus bridge and is forming secondary xylem and phloem. | Graft-incompatibility in horticultural crops
