Application of the TRAP technique to lettuce (Lactuca sativa L.) genotyping

Abstract

To demonstrate the applicability of the target region amplification polymorphism (TRAP) marker technique to lettuce genotyping, we fingerprinted 53 lettuce (Lactuca sativa L.) cultivars and six wild accessions (three from each of the two wild species, L. saligna L. and L. serriola L.). Seven hundred and sixty-nine fragments from 50 to 900 bp in length were amplified in 10 PCR reactions using 10 fixed primers in combination with four fluorescent labeled arbitrary primers. Three hundred and eighty-eight of these fragments were polymorphic among the 59 Lactuca entries and 107 fragments were polymorphic among the 53 lettuce cultivars and the six wild accessions; 251 fragments were present only in the wild species. These markers not only discriminated all cultivars, but also revealed the evolutionary relationship among the three species: L. sativa, the cultivated species, is more closely related to L. serriola than to L. saligna. Cluster analysis grouped the cultivars by horticultural types with a few exceptions. These results are consistent with previous findings using RFLP, AFLP, and SAMPL markers. The TRAP markers revealed significant differences in genetic variability among horticultural types, measured by the average genetic similarity among the cultivars of the same type. Within the sample set, the leaf type and butterhead types possessed relatively high genetic variability, the iceberg types had moderate variability and the romaine types had the lowest variability. The genetic behavior of TRAP markers was assessed with a mapping population of 45 recombinant inbred lines (RILs) derived from an interspecific cross between L. serriola and L. sativa. Almost all the markers segregated in the expected 1:1 Mendelian ratio and are being incorporated into the existing lettuce linkage maps. Our results indicate that the TRAP markers can provide a powerful technique for fingerprinting lettuce cultivars.

Analysis of RAPD and AFLP markers linked to resistance to Fusarium oxysporum f. sp. lactucae race 2 in lettuce (Lactuca sativa L.)

“…Markers were concentrated on a few limited linkage groups. It was thought to be due to poor polymorphisms in ice berg lettuce (Hu et al 2005). …”

Genetic Improvement of Maize by Marker-Assisted Breeding

“…TRAP 마커는 18 bp 짜리 2개의 프라이머를 이용하여 한 개의 프라이머는 목표 로 하는 유전자의 EST 데이터베이스를 기반으로 구성되는 고정 프라이머(fixed primer)이며, 다른 하나는 AT 나 GC 비율이 높은 부분에서 인트론이나 엑손과 결합하도록 구성 된 임의의 프라이머를 이용한다 (Hu & Vick, 2003). TRAP 마커는 특정 유전자 염기서열에 대해 개발된 마커이기 때문 에 germplasm 간의 genotyping이나 농업적으로 유용한 유 전 형질에 대한 마커로서 육종에 활용하는 데 많이 이용되 고 있다 (Hu et al, 2005).…”

Genomics Meets Biodiversity: Advances in Molecular Marker Development and Their Applications in Plant Genetic Diversity Assessment

“…Despite this limitation it has been widely used for multiple purposes in different plant species (e.g. Hu et al, 2005;Alwala et al, 2006;Hu et al, 2007).…”