Genetic Mapping With Allele Dosage Information in Tetraploid Urochloa decumbens (Stapf) R. D. Webster Reveals Insights Into Spittlebug (Notozulia entreriana Berg) Resistance

Author(s)

Ulbricht Ferreira, Rebecca Caroline ^[1] ; de Castro Lara, Leticia Aparecida ^[2] ; Chiari, Lucimara ^[3] ; Lima Barrios, Sanzio Carvalho ^[3] ; do Valle, Cacilda Borges ^[3] ; Valerio, Jose Raul ^[3] ; Vilela Torres, Fabricia Zimermann ^[3] ; Franco Garcia, Antonio Augusto ^[2] ; de Souza, Anete Pereira ^{[1, 4]}

Affiliation

^[1] Univ Estadual Campinas, Ctr Mol Biol & Genet Engn, Campinas, SP - Brazil

^[2] Univ Sao Paulo, Genet Dept, Escola Super Agr Luiz de Queiroz, Piracicaba - Brazil

^[3] Brazilian Agr Res Corp, Ernbrapa Beef Cattle, Campo Grande - Brazil

^[4] Univ Estadual Campinas, Plant Biol Dept, Biol Inst, Campinas, SP - Brazil

• Document type: Journal article
• Source: FRONTIERS IN PLANT SCIENCE; v. 10, FEB 21 2019.
• Web of Science Citations: 3

Abstract

Urochloa decumbens (Stapf) R. D. Webster is one of the most important African forage grasses in Brazilian beef production. Currently available genetic-genomic resources for this species are restricted mainly due to polyploidy and apomixis. Therefore, crucial genomic-molecular studies such as the construction of genetic maps and the mapping of quantitative trait loci (QTLs) are very challenging and consequently affect the advancement of molecular breeding. The objectives of this work were to (i) construct an integrated U. decumbens genetic map for a full-sibling progeny using GBS-based markers with allele dosage information, (ii) detect QTLs for spittlebug (Notozulia entreriana) resistance, and (iii) seek putative candidate genes involved in defense against biotic stresses. We used the Setaria viridis genome a reference to align GBS reads and selected 4,240 high-quality SNP markers with allele dosage information. Of these markers, 1,000 were distributed throughout nine homologous groups with a cumulative map length of 1,335.09 cM and an average marker density of 1.33 cM. We detected QTLs for resistance to spittlebug, an important pasture insect pest, that explained between 4.66 and 6.24% of the phenotypic variation. These QTLs are in regions containing putative candidate genes related to defense against biotic stresses. Because this is the first genetic map with SNP autotetraploid dosage data and QTL detection in U. decumbens, it will be useful for future evolutionary studies, genome assembly, and other QTL analyses in Urochloa spp. Moreover, the results might facilitate the isolation of spittlebug-related candidate genes and help clarify the mechanism of spittlebug resistance. These approaches will improve selection efficiency and accuracy in U. decumbens molecular breeding and shorten the breeding cycle. (AU)

• FAPESP's process: 08/52197-4 - Genomic-assisted breeding of sugarcane: using molecular markers for understanding the genetic architecture of quantitative traits and to implement marker assisted selection
• Grantee: Anete Pereira de Souza
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants
• FAPESP's process: 18/19219-6 - Detection of genes of agronomic interest and involved in heterosis in Urochloa spp.
• Grantee: Rebecca Caroline Ulbricht Ferreira
• Support Opportunities: Scholarships in Brazil - Post-Doctorate