The Importance of Crop Wild Relatives for Resistance and Tolerance to Biotic and Abiotic Stresses in Plant Breeding
M. Sait Adak *
Department of Field Crops, Faculty of Agriculture, Ankara University, Ankara, Türkiye.
*Author to whom correspondence should be addressed.
Abstract
Crop wild relatives are important plant genetic resources for broadening the genetic base of cultivated crops and improving their adaptation to biotic and abiotic stresses. Modern crop varieties often have a narrow genetic background because of domestication and intensive selection, which may reduce their capacity to respond to emerging diseases, pests, drought, salinity, temperature extremes and other environmental constraints. This chapter reviews the role of crop wild relatives as sources of useful alleles for plant breeding, with emphasis on resistance and tolerance traits. The discussion highlights the value of wild relatives in major crop groups, including cereals, legumes, solanaceous crops, cotton and sugar beet. The examples presented show that wild germplasm has been used to improve resistance to fungal, bacterial, viral, insect and nematode stresses, as well as tolerance to drought, salinity, cold, heat and waterlogging. The chapter also emphasises that the successful use of crop wild relatives depends on crossing compatibility, cytogenetic relationships, hybrid fertility, germplasm availability, phenotyping and the application of conventional and modern breeding approaches. Although the transfer of useful traits from wild species can be technically challenging, crop wild relatives remain valuable reservoirs for developing resilient cultivars. Their collection, conservation, characterisation and systematic use are therefore essential for strengthening plant breeding programmes and supporting sustainable crop production under changing environmental conditions.
Keywords: Crop wild relatives, biotic stress, abiotic stress, plant breeding, genetic resources