Plant genetic resources management and pre-breeding in genomics era
Plant Genetic Resources (PGR) conserved in gene bank provides genetic variability for efficient utilization in breeding programmes. Pre-breeding is required for broadening the genetic base of the crop through identification of useful traits in un-adapted materials and transfer them into better adapted ones for further breeding. So, pre-breeding is a promising alternative (due to use of un-adapted materials) to link genetic resources and breeding programs. Utilization of PGR in crop improvement programmes including prebreeding have been very limited. Advances in genomics have provided us with high-quality reference genomes, sequencing and re-sequencing platforms with reduced cost, marker and QTL assisted selection, genomic selection and population level genotyping platforms. Further, genome editing tools like, CRISPR/Cas9 and its latest modification base editing technology can be used to generate target specific mutants and are important for establishing gene functions with respect to their phenotypes through developing knockout mutations. These new genomic tools can be used to generate, analyse and manipulate the genetic variability for designing cultivars with the desired traits. The genomic tools has not only accelerated the utilization of PGR but also assisted pre-breeding through rapid selection of trait-specific germplasm, reduced periods in breeding cycle for confirming gene of interest in intermediate material and validation of transfer of gene of interest in the cultivated gene pool. In crops, where limited genetic and genomic resources are available, pre-breeding becomes very challenging. We can say that genomics assisted utilization of PGR and prebreeding has accelerated the pace of introgression of complex traits in different crop cultivars.and yield plateau has already been achieved in these cultivars (Chen et al. 2014a). Under these circumstances, use of Plant Genetic Resources (PGR) in crop improvement programs provides an avenue to solve the problem.