Institute of Crop Molecular Breeding, The Shennong Laboraory, Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Henan Provincial Key Laboratory for Oil Crops Improvement, Postgraduate T&R Base of Zhengzhou University, Henan Academy of Agricultural Sciences, Ministry of Agriculture, Zhengzhou, 450002, China.
School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450002, China.
BMC Genomics. 2024 Jan 16;25(1):65. doi: 10.1186/s12864-024-10005-x.
Pod shell thickness (PST) is an important agronomic trait of peanut because it affects the ability of shells to resist pest infestations and pathogen attacks, while also influencing the peanut shelling process. However, very few studies have explored the genetic basis of PST.
An F segregating population derived from a cross between the thick-shelled cultivar Yueyou 18 (YY18) and the thin-shelled cultivar Weihua 8 (WH8) was used to identify the quantitative trait loci (QTLs) for PST. On the basis of a bulked segregant analysis sequencing (BSA-seq), four QTLs were preliminarily mapped to chromosomes 3, 8, 13, and 18. Using the genome resequencing data of YY18 and WH8, 22 kompetitive allele-specific PCR (KASP) markers were designed for the genotyping of the F population. Two major QTLs (qPSTA08 and qPSTA18) were identified and finely mapped, with qPSTA08 detected on chromosome 8 (0.69-Mb physical genomic region) and qPSTA18 detected on chromosome 18 (0.15-Mb physical genomic region). Moreover, qPSTA08 and qPSTA18 explained 31.1-32.3% and 16.7-16.8% of the phenotypic variation, respectively. Fifteen genes were detected in the two candidate regions, including three genes with nonsynonymous mutations in the exon region. Two molecular markers (Tif2_A08_31713024 and Tif2_A18_7198124) that were developed for the two major QTL regions effectively distinguished between thick-shelled and thin-shelled materials. Subsequently, the two markers were validated in four F lines selected.
The QTLs identified and molecular markers developed in this study may lay the foundation for breeding cultivars with a shell thickness suitable for mechanized peanut shelling.
豆壳厚度（PST）是花生的一个重要农艺性状，因为它影响豆壳抵抗害虫侵害和病原体攻击的能力，同时也影响花生脱壳过程。然而，很少有研究探索 PST 的遗传基础。
利用厚壳品种粤优 18（YY18）和薄壳品种潍花 8（WH8）杂交衍生的 F 分离群体，鉴定 PST 的数量性状位点（QTLs）。基于混池分离群体测序（BSA-seq），初步将 4 个 QTL 定位在 3、8、13 和 18 号染色体上。利用 YY18 和 WH8 的基因组重测序数据，为 F 群体的基因型设计了 22 个竞争性等位基因特异性 PCR（KASP）标记。鉴定并精细定位了两个主要 QTL（qPSTA08 和 qPSTA18），qPSTA08 位于 8 号染色体（0.69-Mb 物理基因组区域），qPSTA18 位于 18 号染色体（0.15-Mb 物理基因组区域）。此外，qPSTA08 和 qPSTA18 分别解释了 31.1-32.3%和 16.7-16.8%的表型变异。在两个候选区域检测到 15 个基因，包括外显子区域有 3 个非同义突变的基因。为两个主要 QTL 区域开发的两个分子标记（Tif2_A08_31713024 和 Tif2_A18_7198124）有效地区分了厚壳和薄壳材料。随后，在四个选定的 F 系中验证了这两个标记。
本研究鉴定的 QTLs 和开发的分子标记可能为培育适合机械化花生脱壳的品种奠定基础。
