Alien Gene Transfer in Crop Plants: An Introduction

Abstract

Alien gene transfer in crop plants has led to tremendous improvement in various crop species. Wild species are rich resources of useful alien genes which are not available in the cultivated gene pool. These include genes for resistance to diseases and insect pests; for tolerance to drought, salinity, temperature extremities and other abiotic stresses as well as for quality traits. While most of the alien gene introgressions in crop plants have been achieved through vertical gene transfer, horizontal gene transfer through transgenesis, somatic hybridization and, most recently, intragenesis and cisgenesis has invoked tremendous interest of the scientific community globally. These techniques, lately aided by molecular markers and in situ hybridization, together have led to introgression of hundreds of genes of interest in cultivated background of crop species, thereby improving their genetic potential. This chapter provides an insight into importance and need of alien gene transfer, various methods to achieve it, alien gene detection and role of alien gene transfer in creating variability.