**Author details**

Recently, association mapping is performed [36] for biomass-related traits in 208 sorghum accessions of Pakistan. Diversity and structure analysis as well as association mapping analysis were performed on 94 diverse accessions, which were selected through PCA of 208 sorghum accessions. About 215 alleles were detected with an average of 3.47 alleles per locus. The range of alleles varied from 2 to 5. The polymorphic SSR markers were used to identify molecular diversity, population structure, linkage disequilibrium, and marker trait associations (MTAs). Major allele frequency was ranged from 0.13 to 0.74. The average PIC value of primers was 0.51 that ranged from 0.25 to 0.62. The admixture model-based structure analysis revealed four admixture subpopulations, which indicated that all domesticated cultivars had common ancestor with continuous gene flow. The haplotype LD block analysis showed strong linkage between xtxp219 (located at 66.13 Mb) and Xcup37 (located at 61.90 Mb) with the R2 value of 1.00, which depicted that no recombinational event occurred between these two loci on chromosome 6. The markers, Xcup12 (54.22 Mb) and sb4–sb72 (41.44 Mb) were strongly linked with R2 value of 0.90. The markers within the range of R2 value 0.60–0.70 were Xcup36 (47.11 Mb), xtxp127 (44.97 Mb), xtxp045 (49.28 Mb), sb4–sb72 (41.44 Mb), SB3630 (52.81 Mb), and xtxp127 (44.97) on chromosome 6. The LD decay was estimated to be up to 10 Mb in case of chromosome 6 with R2 value of 0.440 by using 23 polymorphic SSRs. The haplotype LD block analysis of chromosome 9 showed strong linkage between SB5111 and Xcup18 with R2 value of 1.00. The pair-wise LD decay analysis revealed LD decay at 50 kb at

Seven marker trait associations (MTAs) were detected by mixed linear model (MLM) approach with phenotypic variability ranging from 9.13 to 13.9% for the first year and from 6.25 to 23.05% for the second year. Four MTAs were associated with plant height, days to 50% flowering, and leaf length on chromosome 6 and three on chromosome 9 with the same traits. A total of five SSR markers expressed significant MTAs; three of these (Xgap072, Xtxp265, and SB3789) were associated with plant height, days to 50% flowering, and leaf length traits on chromosome 6. Two markers Xtxp283 and SB5040 were associated with plant height, leaf length, and days to 50% flowering on chromosome 9. Hence, chromosomes 6 and 9 appeared

Considering the global drive to explore alternate sources of renewable energy, biomass sorghum stands out for meeting economic demands like greater variability, short development cycle, and high calorific value in boilers. Moreover, sorghum is a good genetic model having integrated genetics-genomics-breeding platform, wide adaptability across varying environments, and diverse germplasm across the globe exploited for food, feed, fiber, and biofuel. Our chapter describes the efforts being carried out to identify and improve biomass in sorghum genotypes with great agronomic and energetic potential, dissecting sorghum genome by using omics approaches to explain the genetics of these traits and documenting the association of these traits with the genetic fingerprints of sorghum crop. The scientific record suggests that there is abundant genetic variation within existing sorghum germplasm to play

to carry important QTLs for biomass-related traits in sorghum.

around for developing high-biomass sorghum.

R2 value of 0.023.

32 Advances in Biofuels and Bioenergy

**6. Conclusion**

Bushra Sadia1,2\*, Faisal Saeed Awan1 , Fozia Saleem1 , Hafeez Ahmad Sadaqat<sup>3</sup> , Sarmad Frogh Arshad1 and Haseeb Shaukat1

\*Address all correspondence to: bushra.sadia@uaf.edu.pk

1 Centre of Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture, Faisalabad (UAF), Pakistan

2 US-Pakistan Centre for Advanced Studies in Agriculture and Food Security (USPCAS-AFS), University of Agriculture, Faisalabad (UAF), Pakistan

3 Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad (UAF), Pakistan
