Genome size variation provided novel insights into agronomic trait correlated effects and revealed intraspecific diversity in Jerusalem artichoke (Helianthus tuberosus L.)

Abstract

Genome survey technology The Jerusalem artichoke (Helianthus tuberosus L.) holds great significance as a crop for inulin production. However, the absence of a sequenced Jerusalem artichoke genome has hindered the advancement of genetic resources and molecular research regarding this plant. Furthermore, no research the investigations into potential variations in genome size among Jerusalem artichoke species and their impact on agronomic traits have not been conducted. This study endeavors to explore the genome size of Jerusalem artichoke and its interaction with the plant's agronomy. To estimate the genome size of Jerusalem artichoke, the cultivar JA1155 underwent genome analysis using flow cytometry and K-mers. Additionally, flow cytometry was employed to determine the genome size of eight remaining Jerusalem artichoke germplasms and establish a correlation with their phenotypic characteristics. The results of flow cytometry revealed an estimated genome size (2C) of 21.96 Gb for JA1155. Moreover, the Genome Survey results indicated that the genome size of JA1155 (2C) was estimated to be 21.36 Gb, mirroring the findings of flow cytometry. The heterozygosity rate of the JA1155 gene set was 1.21%, with a duplication rate of 92.25%. Following the initial genome assembly, the contig N50 reached 165 bp, encompassing a total length of 10,616.86 Mbp, while the scaffold N50 was 172 bp, totaling 10,772.62 Mbp in length. Flow cytometry results demonstrated a wide range of genome sizes among the measured Jerusalem artichoke genomes, ranging from 20.51 to 23.23 Gb (2C). Additionally, we discovered significant correlations between genome size and several agronomic traits in Jerusalem artichoke, namely total tuber weight (p<0.01, r=0.474), leaf length (p<0.01, r=0.319), plant height (p<0.01, r=0.267), and aboveground weight (p<0.05, r=0.229). This study not only aids in completing the genome sequencing of Jerusalem artichoke but also offers valuable insights into the connection between genome size and agronomic traits. Future research should address the interplay of these mechanisms by tackling various related inquiries.