Almeida-Pereira C S, Silva A V C, Alves R P, Feitosa-Alcantara R B, Arrigoni-Blank M F, Alvares-Carvalho S V, Costa T S, White L A S, Pinto V S, Sampaio T S, Blank A F
Laboratório de Recursos Genéticos Vegetais e Óleos Essenciais, Departamento de Engenharia Agronômica, Universidade Federal de Sergipe, São Cristóvão, SE, Brasil.
Laboratório de Biologia Molecular, Embrapa Tabuleiros Costeiros, , Brasil.
Genet Mol Res. 2017 May 18;16(2):gmr-16-02-gmr.16029602. doi: 10.4238/gmr16029602.
Brazil has about 300 Croton species in different types of vegetation. Croton tetradenius Baill., which is endemic to the Northeast region and predominant in the Caatinga vegetation, stands out among the several species of this genus. Considering the importance of knowing the genetic variability of a species, the objective of this study was to analyze the genetic diversity of the genotypes of natural populations of C. tetradenius in the State of Sergipe, using ISSR molecular markers. Forty individuals were sampled in four natural populations of the State of Sergipe, Brazil. Thirteen primers were used for DNA amplification using ISSR-PCR, totaling 77 amplified fragments, of which 94.8% were polymorphic. Results of the cluster analysis obtained by the Jaccard's similarity index, using the UPGMA method, resulted in the formation of six distinct clusters. Analysis of molecular variance (AMOVA), used to estimate the genetic variability among populations, revealed significant genetic variance (P < 0.01) between and within the studied populations, and most of the genetic diversity was found (87%) within populations. According to the Jaccard's similarity index, none of the studied plants was genetically identical. CTE210 and CTE305 presented high similarity index (0.76), while CTE105 presented low similarity index (<0.16) with all related individuals. ISSR markers were efficient and allowed the formation of a molecular profile, and had sufficient polymorphism to estimate the genetic variability between the accessions of the studied populations.
巴西不同类型植被中有约300种巴豆属植物。巴豆（Croton tetradenius Baill.）是巴西东北部特有的物种，在卡廷加植被中占主导地位，在该属的多个物种中尤为突出。考虑到了解一个物种遗传变异性的重要性，本研究的目的是利用ISSR分子标记分析塞尔希培州巴豆自然种群基因型的遗传多样性。在巴西塞尔希培州的四个自然种群中采集了40个个体样本。使用13条引物通过ISSR-PCR进行DNA扩增，共获得77个扩增片段，其中94.8%具有多态性。采用UPGMA方法，根据Jaccard相似性指数进行聚类分析，结果形成了六个不同的聚类。用于估计种群间遗传变异性的分子方差分析（AMOVA）显示，研究种群之间和种群内部均存在显著的遗传方差（P < 0.01），且大部分遗传多样性（87%）存在于种群内部。根据Jaccard相似性指数，所研究的植物在遗传上均不相同。CTE210和CTE305表现出较高的相似性指数（0.76），而CTE105与所有相关个体的相似性指数较低（<0.16）。ISSR标记是有效的，能够形成分子图谱，且具有足够的多态性来估计研究种群材料间的遗传变异性。
