Deo Thamiris G, Ferreira Rebecca C U, Lara Letícia A C, Moraes Aline C L, Alves-Pereira Alessandro, de Oliveira Fernanda A, Garcia Antonio A F, Santos Mateus F, Jank Liana, de Souza Anete P
Center for Molecular Biology and Genetic Engineering, University of Campinas, Campinas, Brazil.
Genetics Department, Escola Superior de Agricultura "Luiz de Queiroz," University of São Paulo, Piracicaba, Brazil.
Front Plant Sci. 2020 Feb 26;11:15. doi: 10.3389/fpls.2020.00015. eCollection 2020.
Forage grasses are mainly used in animal feed to fatten cattle and dairy herds, and guinea grass () is considered one of the most productive of the tropical forage crops that reproduce by seeds. Due to the recent process of domestication, this species has several genomic complexities, such as autotetraploidy and aposporous apomixis. Consequently, approaches that relate phenotypic and genotypic data are incipient. In this context, we built a linkage map with allele dosage and generated novel information of the genetic architecture of traits that are important for the breeding of . From a full-sib progeny, a linkage map containing 858 single nucleotide polymorphism (SNP) markers with allele dosage information expected for an autotetraploid was obtained. The high genetic variability of the progeny allowed us to map 10 quantitative trait loci (QTLs) related to agronomic traits, such as regrowth capacity and total dry matter, and 36 QTLs related to nutritional quality, which were distributed among all homology groups (HGs). Various overlapping regions associated with the quantitative traits suggested QTL hotspots. In addition, we were able to map one locus that controls apospory (apo-locus) in HG II. A total of 55 different gene families involved in cellular metabolism and plant growth were identified from markers adjacent to the QTLs and APOSPORY locus using the genome as a reference in comparisons with the genomes of and . Our results provide a better understanding of the genetic basis of reproduction by apomixis and traits important for breeding programs that considerably influence animal productivity as well as the quality of meat and milk.
饲草主要用于动物饲料，以育肥牛群和奶牛群，而俯仰臂形草（）被认为是通过种子繁殖的热带饲草作物中产量最高的品种之一。由于最近的驯化过程，该物种存在一些基因组复杂性，如同源四倍体和无孢子无融合生殖。因此，将表型和基因型数据相关联的方法尚处于起步阶段。在此背景下，我们构建了一个具有等位基因剂量的连锁图谱，并生成了俯仰臂形草育种中重要性状遗传结构的新信息。从一个全同胞后代中，获得了一个包含858个单核苷酸多态性（SNP）标记的连锁图谱，这些标记具有同源四倍体预期的等位基因剂量信息。后代的高遗传变异性使我们能够定位10个与农艺性状相关的数量性状位点（QTL），如再生能力和总干物质，以及36个与营养品质相关的QTL，它们分布在所有同源群（HG）中。与数量性状相关的各种重叠区域表明存在QTL热点。此外，我们能够在HG II中定位一个控制无孢子生殖的位点（无孢子位点）。以俯仰臂形草基因组为参考，与玉米和高粱基因组进行比较，从与QTL和无孢子生殖位点相邻的标记中总共鉴定出55个参与细胞代谢和植物生长的不同基因家族。我们的结果为更好地理解无融合生殖的遗传基础以及对育种计划重要的性状提供了帮助，这些性状会极大地影响动物生产力以及肉和奶的质量。
