School of Biological Science and Engineering, North Minzu University, Yinchuan, 750021, China.
State Key Laboratory of Efficient Production of Forest Resources, Yinchuan, 750004, China.
BMC Plant Biol. 2024 May 23;24(1):441. doi: 10.1186/s12870-024-05092-7.
Goji (Lycium barbarum L.) is a perennial deciduous shrub widely distributed in arid and semiarid regions of Northwest China. It is highly valued for its medicinal and functional properties. Most goji varieties are naturally self-incompatible, posing challenges in breeding and cultivation. Self-incompatibility is a complex genetic trait, with ongoing debates regarding the number of self-incompatible loci. To date, no genetic mappings has been conducted for S loci or other loci related to self-incompatibility in goji.
We used genome resequencing to create a high-resolution map for detecting de novo single-nucleotide polymorphisms (SNP) in goji. We focused on 229 F1 individuals from self-compatible '13-19' and self-incompatible 'new 9' varieties. Subsequently, we conducted a quantitative trait locus (QTL) analysis on traits associated with self-compatibility in goji berries. The genetic map consisted of 249,327 SNPs distributed across 12 linkage groups (LGs), spanning a total distance of 1243.74 cM, with an average interval of 0.002 cM. Phenotypic data related to self-incompatibility, such as average fruit weight, fruit rate, compatibility index, and comparable compatibility index after self-pollination and geitonogamy, were collected for the years 2021-2022, as well as for an extra year representing the mean data from 2021 to 2022 (2021/22). A total of 43 significant QTL, corresponding to multiple traits were identified, accounting for more than 11% of the observed phenotypic variation. Notably, a specific QTL on chromosome 2 consistently appeared across different years, irrespective of the relationship between self-pollination and geitonogamy. Within the localization interval, 1180 genes were annotated, including Lba02g01102 (annotated as an S-RNase gene), which showed pistil-specific expression. Cloning of S-RNase genes revealed that the parents had two different S-RNase alleles, namely S1S11 and S2S8. S-genotype identification of the F1 population indicated segregation of the four S-alleles from the parents in the offspring, with the type of S-RNase gene significantly associated with self-compatibility.
In summary, our study provides valuable insights into the genetic mechanism underlying self-compatibility in goji berries. This highlights the importance of further positional cloning investigations and emphasizes the importance of integration of marker-assisted selection in goji breeding programs.
枸杞（Lycium barbarum L.）是一种分布广泛的多年生落叶灌木，分布在中国西北干旱和半干旱地区。它因其药用和功能特性而备受重视。大多数枸杞品种是天然自交不亲和的，这给其繁殖和栽培带来了挑战。自交不亲和是一种复杂的遗传特征，关于自交不亲和的位点数量一直存在争议。迄今为止，还没有对枸杞的 S 位点或其他与自交不亲和相关的基因座进行遗传图谱构建。
我们使用基因组重测序创建了一个高分辨率图谱，用于检测枸杞中的从头单核苷酸多态性（SNP）。我们专注于自交亲和品种“13-19”和自交不亲和品种“新 9”的 229 个 F1 个体。随后，我们对与枸杞浆果自交亲和相关的性状进行了数量性状位点（QTL）分析。遗传图谱由分布在 12 个连锁群（LG）上的 249327 个 SNPs 组成，总长度为 1243.74cM，平均间隔为 0.002cM。2021-2022 年收集了与自交不亲和相关的表型数据，如平均果实重量、果实率、亲和指数和自交授粉和同株异花授粉后的可比亲和指数，以及代表 2021-2022 年平均值的额外一年（2021/22）的数据。共鉴定到 43 个与多个性状相关的显著 QTL，占观察到的表型变异的 11%以上。值得注意的是，2 号染色体上的一个特定 QTL 在不同年份都存在，无论自交和同株异花授粉之间的关系如何。在定位区间内，注释了 1180 个基因，包括 Lba02g01102（注释为 S-RNase 基因），其表现出雌蕊特异性表达。S-RNase 基因的克隆表明，亲本具有两个不同的 S-RNase 等位基因，即 S1S11 和 S2S8。F1 群体的 S 基因型鉴定表明，四个 S 等位基因在后代中从亲本中分离出来，S-RNase 基因的类型与自交亲和性显著相关。
综上所述，我们的研究为枸杞浆果自交亲和的遗传机制提供了有价值的见解。这凸显了进一步进行定位克隆研究的重要性，并强调了在枸杞育种计划中整合标记辅助选择的重要性。
