Research on horticultural crops, particularly on 'crop improvement and breeding' has been taken up by many State Agricultural Universities and ICAR institutes with the result the genetic base of a number of horticultural crops has been broadened and many improved cultivars have been developed despite the fact the breeding is relatively cumbersome in many horticultural crops vis a vis agricultural crops. The information on these aspects are scattered in many reports, which are sometime beyond the reach of the students. Hence, this book 2nd fully revised and expanded edition has been specially written with the hope that it may provide a satisfactory guidance for students of agriculture and horticulture including applied botany and also for the horticultural enthusiasts. More emphasis has been given in this book to explain the principles and methods of breeding of important Horticulture Crops and also the achievements made in these crops in the development of new cultivars. The book has been designed with the main consideration to serve a dual purpose of being a text and reference. Keeping this thing in mind the entire book has been divided into three major parts. The first part deals with the principles and methods of breeding adopted in horticultural crops propagated both sexually and asexually. The second part deals with the achievements in breeding of perennial horticultural crops. The third part covers achievements made in breeding of annual horticultural crops.