Genetic Relationships Analysis of Lime and Acid Citrus by ISSR Markers

Abstract

The major commercial lime cultivars in Thailand are Mexican lime (Citrus aurantifolia (Christm.) Swingle) and Tahiti lime (C. latifolia (Yu. Tanaka) Tanaka). Nevertheless, those cultivars are not resistant to diseases or the fruit qualities are not meet the demand. To improve new cultivars, lime and acid Citrus germplasms are the sources of parental lines. Together, the study of the genetic relationship between lime and acid Citrus germplasms will benefit the parental lines selection. This study aims to study the genetic relationships of 55 accessions of lime and acid Citrus germplasms with Inter Simple Sequence Repeat (ISSR) markers. Four primers of ISSR generated 33 DNA bands with 87.5% polymorphism. Dendrogram revealed the ability of 4 ISSR primers to cluster lime and acid Citrus into four groups, a group of Mexican lime and Tahiti lime, a group of citron and lemon, a group of kaffir lime, and a group of finger lime which were able to classified lime and acid Citrus according to their species. Focusing on 26 accessions of Mexican lime, ISSR primer 814 could distinguish Mexican lime into two groups. Group A contained 13 accessions in which the average fruit weight, fruit rind thickness, and seed number were all less than group B which also contained 13 accessions.