The procedure that ensures retention of the desired characteristics repeatedly in large populations of future generations of the tomato crop is:
Micropropagation: Healthy explants are taken from the tomato plants and grown in sterile conditions in special nutrient medium. The tomato plants produced from tissue culture are genetically identical to the original plant from which they are grown, so they are called somaclones. Also, through micropropagation more number of tomato plants can be produced in a short time period.