Harnessing Crop Wild Relatives for Crop Improvement

Abstract

Crop wild relatives (CWRs) are the potential source of novel traits and genetic variation in food crops with narrow genetic base. CWRs include immediate progenitor of crop species and other species of plants which are closer to them in near evolutionary history. CWRs are the sources of novel alleles for several important traits of nutritional and agronomical importance. Introgression of such valuable alleles into working germplasm of a breeding programme depends on sexual compatibility of CWRs with crop species in cultivation. Scientific techniques have been developed to overcome compatibility among them up to certain extent. Simultaneous discovery and transfer of useful alleles into cultivable background have been demonstrated in certain crop species with success. Utilisation of completely incompatible species has been made easier by methods such as somatic hybridization. With ever increasing innovations in the field of genomics science, hope to harness the potential of CWR has grown up to new heights. CWRs have been successfully utilised to enhance quality of crop produce in wheat, barley, tomato, etc., and also have been exploited to create new species such as triticale as well as to understand crop evolutionary history in different crops. CWRs are also a good source of cytoplasmic male sterility which makes them amenable to boost commercial breeding programs. Many CWRs are natural source of abiotic and biotic stresses. Importance of CWR has become more relevant in the era where threat of climate change is apparent and mitigation approaches such as transgenics are being increasingly criticised on many fronts. In the era facing the challenges of genetic erosion of diversity and extinction of species, systematic collection, conservation, and characterization of available genetic diversity of CWRs is immensely important. Prebreeding of wild germplasm is among other challenges for successful utilization of such highly potential genetic resources for enhancing crop breeding efforts.