Genome-wide association mapping of latex yield and girth in Amazonian accessions of Hevea brasiliensis grown in a suboptimal climate zone

摘要

Abstract Latex yield and growth are the key complex traits in commercial rubber production. The present study is the first to report genome-wide association mapping of latex yield and girth, for 170 Amazonian accessions grown in a suboptimal area characterized by limited rainfall and a lengthy dry season. Targeted sequence enrichment to capture gene transcripts generated 14,155 high quality filtered single nucleotide polymorphisms (SNPs) of which 94.3% resided in coding regions. The rapid decay of linkage disequilibrium over physical and genetic distance found in the accessions was comparable to those previously reported for several outcrossing species. A mixed linear model detected three significant SNPs in three candidate genes involved in plant adaptation to drought stress, individually explaining 12.7–15.7% of the phenotypic variance. The SNPs identified in the study will help to extend understanding, and to support genetic improvement of rubber trees grown in drought-affected regions. Highlights ? The first genome-wide association mapping of latex yield and girth of rubber trees grown in a suboptimal area was reported. ? Targeted sequence enrichment to capture gene transcripts generated 14,155 high quality filtered SNPs of which 94.3% resided in coding regions. ? The rapid decay of LD over physical and genetic distance found in the accessions is comparable to those previously reported for several outcrossing species. ? All the SNP-trait associations were involved in plant adaptation to drought stress.