Mutation breeding as a separate branch of research was abandoned in Western countries. Almost all the mutants exhibited ‘ negative selection values, ’ that is, they died or were weaker than wild varieties. ”
उत्परिवर्तनांकरवी पैदास करण्याची जी संशोधनाची वेगळी शाखा सुरू करण्यात आली होती ती पाश्‍चात्त्य देशांत बंद करण्यात आली.