**Conflict of interest**

*Genetic Variation*

targeted genes [59].

**6. Prospects**

techniques are zinc finger nuclease (ZFN) technology, oligonucleotide-directed mutagenesis (ODM), cisgenesis and intragenesis, grafting on GM-rootstock, RNAdependent DNA methylation, agro-infiltration "sensustricto," and reverse breeding. The ZFN tool one of the site-directed nuclease (SDN) can be implemented to create a site-specific mutation in the plant genome. In addition, a number of new SDN techniques have been introduced viz. TALEN and CRISPR/Cas, and the latter is now extensively being used [57]. Recently, IAEA and FAO jointly launched a program known as Plant Mutation Breeding Network (PMBN) on the basis of a large number of crop varieties (2000) in the Asia Pacific region [58]. Out of these, 826 rice varieties to date have been released using mutation breeding, of these 699 were from the Asia-pacific region, with 290 from china. This program will be beneficial to farmers and researchers by developing new improved varieties with a higher yield, stability, and quality traits, disease resistance and resilience to changing climates through mutagenesis. The PMBN will work to further expand these great achievements jointly among the member countries. The conjoint use of classical mutation breeding method through screening of TILLING populations NBT mutations can be employed implicitly in the modification of plant attributes. The main advantage of NBT over the classical mutation technique is its precision and specificity that could be utilized to find robust mutation sites without the unwanted genetic changes that are the main problem in the classical mutation breeding. Resultantly, desired mutations could be retrieved through traditional mutation techniques. This is a lengthy process but of high applicability because of efficient tools to create mutant populations and to screen these mutations for

With the rising food demands, the development of new crop varieties with improved yield potential and better resistance to biotic and abiotic stresses is vital. Modern techniques, molecular, and omics are the tools in hand to speed up the breeding route in integration with conventional (mutation/hybridization) methods. The integrated approach of using genomic and omics data with genetic and phenotypic data helps to unfold the genes/pathways connected with desired traits [60]. The conventional breeding methods have been employed extensively in combination with transformation, gene editing and marker-assisted selection (MAS). The selection of suitable parental materials endowed with desired traits in different crop species is fundamental for any successful breeding program. The highly favored markers known as Single Nucleotide Polymorphisms (SNPs) are helpful to analyze genetic variability and population configuration, in constructing genetic maps and to present genotypes for GWAS (genome-wide association analysis) [61]. Singlenucleotide polymorphisms (SNPs) are markers of choice to detect genetic diversity in crop plants [62]. Genotyping by sequencing (GBS) technique is based on nextgeneration-sequencing also done with SNP markers to incorporate high throughput genotyping [63]. These molecular techniques in combination with NBTs can do a miraculous job in the future to develop environment resilient cultivars to help fight-

Mutation breeding has substantially contributed to crop improvements worldwide. Thousands of mutant crop varieties released in different countries

**94**

ing food security.

**7. Conclusions**

The authors declare no conflict of interest.
