Yield is an agronomic trait of major interest in the breeding for cash crops such as cashew. Despite its worldwide growing interest, the genetic architecture and molecular mechanisms associated with cashew nut yield are poorly understood. This study was aimed at the identification of quantitative trait nucleotides (QTNs) and candidate genes associated with yield components through a genome-wide association study (GWAS). Data from six yield components were collected on 232 potentially high-yielding cashew trees during two consecutive harvest seasons. Using the genotyping-by-sequencing method, 3620 cleaned SNPs were identified across the cashew genome. All these data were used in GWAS using the mrMLM-GWAS algorithm in R software. A total of 95 QTNs significantly associated with tree nut yield were identified but at the set threshold, the other five traits were not significantly associated with any SNPs. These QTNs were found colocated with candidate genes located within 10 kilobase (kb) and resulted in the detection of 97 putative genes. The analysis of the functions of these genes highlighted nine ( Anaoc.0005s0124.1 , Anaoc.0016s0111.1 , Anaoc.0011s1462.1 , Anaoc.0010s1145.1 , Anaoc.0010s1144.1, Anaoc.0010s0529.1, Anaoc.0007s1304.1, Anaoc.0016s0113.1, Anaoc.0006s0105.1 ) likely playing a significant influence on yield. The extent to which these genes could contribute to yield is discussed and their in-depth study could offer new molecular marker tools for varietal selection in cashew.
Yao et al. (Wed,) studied this question.