Characterization and Genetic Mapping of Black Root RotResistance in <i>Gossypium arboreum</i> L.

• Main Authors: Iain W. Wilson, Philippe Moncuquet, Marc Ellis, Rosemary G. White, Qian-Hao Zhu, Warwick Stiller, Danny Llewellyn
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Thielaviopsis basicola</i>; <i>Berkleyomyces rouxiae</i>; black root rot; disease resistance; <i>Gossypium arboreum</i>; transcriptome analysis
• Online Access: https://www.mdpi.com/1422-0067/22/5/2642

Black root rot (BRR) is an economically important disease of cotton and other crops, especially in cooler regions with short growing seasons. Symptoms include black discoloration of the roots, reduced number of lateral roots and stunted or slow plant growth. The cultivated tetraploid Gossypium species are susceptible to BRR. Resistance to BRR was identified in <i>G. arboreum</i> accession BM13H and is associated with reduced and restricted hyphal growth and less sporulation. Transcriptome analysis indicates that BM13H responds to infection at early time points 2- and 3-days post-inoculation, but by day 5, few differentially expressed genes are observed between infected and uninfected roots. Inheritance of BM13H resistance to BRR was evaluated in an F₆ recombinant inbred population and shows a single semi-dominant locus conferring resistance that was fine mapped to a region on chromosome 1, containing ten genes including five putative resistance-like genes.