Genome mapping in F1 population of crossbred Italia and Mercan grape varieties: Establishment of AFLP and SSR linkage groups towards significant morphological characters and fungal diseases

Abstract

This research aims at the establishment of a genome map for F₁ population developed by crossbreeding of Italia and Mercan grape varieties. A co-dominant marker SSR (Simple Sequence Repeats) and a dominant marker AFLP (Amplified Fragment Length Polymorphism) were used in the study. Double-pseudotestcross mapping technique was used for genome mapping. The study analyzed 60 plants selected from the F₁ population as well as the parental grape varieties, which differed in regards to resistance to diseases and some morphological characteristics. Amplification products were evaluated as “available” and “not available” at the end of silver staining for SSR and radioactive marking for AFLP. Polymorphic loci were determined according to their segregation ratios ranging between 1: 1 and 3: 1 at the end of X² tests. 3.0 LOD value was used in Mapmaker/Exp 3.0 package program for mapping. Two separate genetic linkage maps (maternal and paternal) were observed which included 6 and 1 linkage groups, respectively. Linkage of the loci located on the linkage groups to the observed diseases and morphological characters were analyzed with regression and variance analyses. A total of 818 primer pairs were tested on the two parents (Italia and Mercan), 60 F₁ (Italia × Mercan population) and two reference grape cultivar (Cabarnet Sauvignon and Merlot), successfully amplifying 112 markers. When the resistance traits to fungal diseases were analyzed during the study, no markers related with resistance to Botrytis cinerea and downy mildew could be found. However, it was found that the markers (VrZAG29a, VrZAG29c) related with the control of resistance to powdery mildew were on a locus which was in linkage group.

Keywords: Vitis vinifera L., grape, SSR, AFLP, mapping

African Journal of Biotechnology Vol. 9(36), pp. 5879-5886, 6 September, 2010