Interspecific cross between Ceratocystis fimbriata and C. manginecans

Some species of Ceratocystis display strong host specificity, such as C. fimbriata sensu stricto that only causes black rot on Ipomoea batatas. Others, such as the closely related C. manginecans, infect Acacia mangium and Mangifera indica but is not pathogenic to I. batatas. Despite the economic impact of these fungal pathogens, knowledge on the genetic factors influencing the pathogenicity and host specificity of Ceratocystis species is limited. A recent inheritance study, based on an interspecific cross between C. fimbriata and C. manginecans and 70 F1 progeny, confirmed that traits such as mycelial growth rate, spore production and aggressiveness toward A. mangium and I. batatas are regulated by multiple genes. A quantitative trait locus (QTL) analysis was performed to determine the genomic loci associated with these traits. All 70 progeny isolates were sequenced, using IonTorrent sequencing technology, and SNP markers were identified to genotype all individuals. The SNP markers were used to construct a genetic linkage map. Using the progeny genotypes and phenotypes, QTLs could be identified on the linkage map for mycelial growth rate and for aggressiveness on A. mangium and I. batatas.