Pre-Breeding's Role in Crop Genetic Improvement. A review

Abstract

The primary challenges limiting grain productivity and production globally are the narrow genetic bases of cultivars and the low exploitation of genetic resources. For genetically enhancing crop productivity, it is necessary to take advantage of new and diversified sources of variation. Important sources of genetic diversity for crop development can be found in wild relatives with increased levels of resilience to or tolerance of various stresses. Cross-incompatibility barriers, however, restrict their use for cultivar improvement and linkage drags. Pre-breeding provides a unique opportunity to solve these issues through the incorporation of desired genes from natural germplasm into genetic backgrounds that may be easily utilized by breeders with minimal linkage drag. The availability of molecular markers will play a significant role in lowering linkage drags and boosting introgression efficiency in pre-breeding
programs. Basic research is done prior to breeding in order to achieve wide crosses and to make it easier to use exotic materials or wild relatives. Finding a desirable trait, capturing its genetic diversity, and transforming those genes into usable form are the steps in pre-breeding. Pre-breeding aims to increase the diversity of improved germplasm while also giving breeders a choice of ready-to-use materials with the traits they want. It is regarded as the first step in sustainable plant breeding and does not considerably diverge from the overall framework of plant breeding. The basis for the sustainable production of different types for current and upcoming challenges that result from the diverse biotic and abiotic stresses is genetic diversity. Pre-breeding offers a unique opportunity for making use of genetic diversity through the introduction of desirable characteristics or genes from wild crop relatives into
cultivated backgrounds utilizing a variety of novel procedures. All plant breeding investigations that take place before cultivar development, testing, and release are referred to as pre-breeding. Pre-breeding is necessary because of the current genetic base's restrictions, the growth of genetically uniform modern varieties, the effects of climate change (better-adapted genes are needed), and the evolution of pest and pathogen populations (which call for new resistance genes). One of the pre-breeding activities that enables to adapt germplasm for immediate use in routine breeding programs is the characterization of landraces/accession, creation of new base population, creation of polyploidy, development of novel breeding procedures, wide cross, and creation of double haploids. In general, there are many opportunities to utilize the use of the pre-breeding benefit, even though pre-breeding adoption faces a
variety of difficulties.