Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA), Estación Experimental Agroindustrial Obispo Colombres (EEAOC)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Las Talitas, Tucumán, Argentina.
Sugarcane Breeding Program of RIDESA/UFSCar, Araras, São Paulo, Brazil.
PLoS One. 2023 Aug 15;18(8):e0289504. doi: 10.1371/journal.pone.0289504. eCollection 2023.
Sugarcane breeding programs incorporate foreign material to broaden the genetic base, expanding the gene pool. In South America, the Inter-university Network for the Development of the Sugarcane Industry (RIDESA) and Estación Experimental Agroindustrial Obispo Colombres (EEAOC) sugarcane breeding programs from Brazil and Argentina, respectively, have never exchanged materials. In that sense, the knowledge of the genetic diversity and population structure among sugarcane genotypes of both germplasm banks, determined in a reliable way through their molecular profiles, will provide valuable information to select the best parental accessions for crossing aimed at the efficient introgression of desirable alleles. For that, the aim was to determine the genetic diversity and population structure of 96 Saccharum commercial hybrids from RIDESA and EEAOC sugarcane breeding programs by using TRAP, SSR and markers related to disease resistance (e.g. Bru1 and G1). Genetic structure was determined through genetic similarity analysis, analysis of molecular variance (AMOVA), Multidimensional scaling (MDS), and a Bayesian method. Average PIC values were 0.25 and 0.26, Ho values were 0.24 and 0.28, and He values were 0.25 and 0.28, for TRAP and SSR primers, respectively. Genetic similarity, MDS, and analysis of structure revealed that Brazilian and Argentinean genotypes clustered in two groups clearly differentiated, whereas AMOVA suggested that there is more variability within programs than between them. Regarding Bru1 markers, Brazilian genotypes showed high frequency of haplotype 1 (71.4%) whereas Argentinean genotypes showed high frequency of haplotype 4 (80.8%); haplotypes 1 and 4 are indicated for the presence and absence of the brown rust resistance gene (Bru1), respectively. Respecting the G1 marker, most of the evaluated genotypes (60.4%) showed the presence of the fragment, in a similar proportion for genotypes of both programs. In conclusion, the exchange of materials, at least the most diverse genotypes, between RIDESA and EEAOC breeding programs will allow extending the genetic base of their germplasm banks, and the knowledge of genetic diversity will help breeders to better manage crosses, increasing the probability of obtaining more productive varieties.
甘蔗育种计划整合外来材料，以拓宽遗传基础，扩大基因库。在南美洲，巴西的大学间甘蔗工业发展网络（RIDESA）和阿根廷的奥比斯波·科伦布雷农业工业实验站（EEAOC）的甘蔗育种计划从未交换过材料。从这个意义上说，通过分子谱图可靠地确定这两个种质库的甘蔗基因型的遗传多样性和群体结构的知识，将为选择用于杂交的最佳亲本提供有价值的信息，以实现理想等位基因的有效导入。为此，目的是利用 TRAP、SSR 和与抗病性相关的标记（例如 Bru1 和 G1），确定来自 RIDESA 和 EEAOC 甘蔗育种计划的 96 个甘蔗商业杂种的遗传多样性和群体结构。通过遗传相似性分析、分子方差分析（AMOVA）、多维尺度分析（MDS）和贝叶斯方法确定遗传结构。TRAP 和 SSR 引物的平均 PIC 值分别为 0.25 和 0.26，Ho 值分别为 0.24 和 0.28，He 值分别为 0.25 和 0.28。遗传相似性、MDS 和结构分析表明，巴西和阿根廷的基因型聚类为两个明显分化的组，而 AMOVA 表明，各计划内的变异性大于计划之间的变异性。关于 Bru1 标记，巴西基因型显示单倍型 1 的高频率（71.4%），而阿根廷基因型显示单倍型 4 的高频率（80.8%）；单倍型 1 和 4 分别表示存在和不存在抗褐色锈病基因（Bru1）。关于 G1 标记，评估的基因型中大多数（60.4%）显示该片段的存在，两个计划的基因型的比例相似。总之，RIDESA 和 EEAOC 育种计划之间至少交换最具多样性的材料，将允许扩大其种质库的遗传基础，遗传多样性的知识将有助于育种者更好地管理杂交，增加获得更具生产力品种的概率。
