Genotypic diversity and genetic parameters of 'Tahiti' acid lime using different rootstocks

Abstract The objective of this work was to estimate the genetic parameters and to evaluate the genotypic diversity of 12 'Tahiti' acid lime (Citrus latifolia) genotypes grafted onto two rootstocks. The experiment was carried out from July 2017 to January 2019, in the municipality of São Mateus, in the state of Espírito Santo, Brazil. Vegetative (stem diameter, canopy projection diameter, and plant height), productive (yield and fruit number), and fruit quality (fruit diameter, soluble solids content, and juice yield) traits were determined. A mixed model was used to estimate heritability and repeatability coefficients, as well as to predict clonal values. Scion diversity was determined through the standardized mean difference of Euclidean distances, and genotypes were clustered by modified Tocher. Clustering quality and trait importance were evaluated using the principal component analysis (PCA). Genotypic variance was observed, which is indicative of the possibility of selection of superior genotypes. The Tocher method showed the presence of three clusters, which is in alignment with the PCA results. The multivariate analyses allows of the selection and the recommendation of superior 'Tahiti' acid lime genotypes.

摘要 本研究旨在估算嫁接于两种砧木的12份塔希提酸莱姆（'Tahiti' acid lime, Citrus latifolia）基因型的遗传参数，并评价其基因型多样性。试验于2017年7月至2019年1月在巴西圣埃斯皮里图州圣马特乌斯市开展。本研究测定了营养生长性状（茎粗、冠幅直径及株高）、生产性状（单株产量及果实数）以及果实品质性状（果实直径、可溶性固形物含量及出汁率）。采用混合模型估算遗传力与重复力系数，并预测无性系值。通过标准化欧氏距离均值差评价接穗多样性，并采用改良Tocher法对基因型进行聚类。采用主成分分析（PCA）评价聚类质量与性状重要性。研究观测到基因型方差，表明筛选优良基因型具备可行性。改良Tocher法将供试材料划分为3个类群，该结果与主成分分析结果一致。多变量分析可为优良塔希提酸莱姆基因型的筛选与推荐提供依据。