Sweet sorghum is an emerging biofuel candidate crop with multiple benefits as a source of biomass energy. Increase of biomass and sugar productivity and quality is a central goal in its improvement. Target region amplified polymorphism (TRAP) is a polymerase chain reaction (PCR) based functional marker system that can detect genetic diversity in the functional region of target genes. Thirty sweet sorghum genotypes were used to study the potential of 24 pairs of TRAP marker system in assessing genetic diversity with regard to three lignin and three sucrose biosynthesis genes. A total of 1638 bands were produced out of which 1161 (70.88%) were polymorphic at least at one locus. The average polymorphic information content (PIC), resolving power (RP), marker index (MI), Shannon’s diversity index (H), and gene diversity values were 0.32, 8.86, 1.74, 3.25, and 0.329, respectively. Analysis of molecular variance (AMOVA) revealed a highly significant genetic variation both within and among accessions studied (P = 0.01). However, the variation within the population was higher than among the populations (accessions). Bootstrap analysis showed that the number of loci amplified using this marker system is sufficient to estimate the available genetic diversity. The thirty genotypes were categorized into five clusters using a similarity matrix at 0.72 coefficient of similarity. The genotypes were also grouped mostly according to their geographic origin where the Ethiopian and Egyptian genotypes tend to fall in specific clusters. Moreover, the genotypes reflected the same pattern of distribution when ordinated using principal coordinate analysis. In conclusion, TRAP marker can be used as a powerful tool to study genetic diversity in sweet sorghum.

中文翻译：

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目标区域扩增多态性（TRAP）标记物识别甜高粱遗传变异性的适用性

甜高粱是一种新兴的生物燃料候选作物，具有多种优势，可作为生物质能的来源。提高生物质和糖的生产率和质量是其改进的主要目标。目标区域扩增多态性（TRAP）是基于聚合酶链反应（PCR）的功能标记系统，可以检测目标基因功能区域的遗传多样性。30种甜高粱基因型用于研究24对TRAP标记系统在评估三个木质素和三个蔗糖生物合成基因遗传多样性方面的潜力。总共产生了1638个条带，其中1161个条带（70.88％）至少在一个位点是多态的。平均多态信息含量（PIC），分辨力（RP），标记指数（MI），香农多样性指数（H）和基因多样性值分别为0.32、8.86、1.74、3。25和0.329。分子变异分析（AMOVA）显示，在所研究的种质内和种之间，遗传差异非常显着（P = 0.01）。但是，种群内部的差异高于种群之间的差异（种质）。引导分析表明，使用该标记系统扩增的基因座数量足以估计可用的遗传多样性。使用相似系数为0.72的相似度矩阵，将30个基因型分为5个簇。基因型也主要根据其地理起源进行分组，其中埃塞俄比亚和埃及的基因型倾向于以特定的簇落入。此外，当使用主坐标分析进行协调时，基因型反映了相同的分布模式。结论，