Genetic mapping of AFLP markers in Japanese bunching onion (Allium fistulosum)

Abstract

The first genetic linkage map of Japanese bunching onion (Allium fistulosum) based primarily on AFLP markers was constructed using reciprocally backcrossed progenies. They were 120 plants each of (P 1 )BC 1 and (P 2 )BC 1 populations derived from a cross between single plants of two inbred lines: D1s-15s-22 (P 1 ) and J1s-14s-20 (P 2 ). Based on the (P 2 )BC 1 population, a linkage map of P 1 was constructed. It comprises 164 markers -149 amplified fragment length polymorphisms (AFLPs), 2 cleaved amplified polymorphic sequences (CAPSs), and 12 simple sequence repeats (SSRs) from Japanese bunching onion, and 1 SSR from bulb onion (A. cepa) -on 15 linkage groups covering 947 centiMorgans (cM). The linkage map of P 2 was constructed with the (P 1 )BC 1 population and composed of 120 loci -105 AFLPs, 1 CAPS, and 13 SSRs developed from Japanese bunching onion and 1 SSR from bulb onion -on 14 linkage groups covering 775 cM. Both maps were not saturated but were considered to cover the majority of the genome. Nine linkage groups in P 2 map were connected with their counterparts in P 1 map using co-dominant anchor markers, 13 SSRs and 1 CAPS.

Mapping of Quantitative Trait Loci Controlling Seedling Growth in Bunching Onion (Allium fistulosum L.)

“…Mapping populations were the same as described by Ohara et al (2005a). Two inbred lines-D1s-15s-22 (Senju group: D) and J1s-14s-20 (Kujo group: J)-were used as the parents.…”

“…Similarly, a D map was constructed using the (J) BC 1 population. SSR markers newly reported by Tsukazaki et al (2007) were mapped on previous maps (Ohara et al, 2005a). Linkage analysis was conducted using a computer program (MAPMAKER/EXP 3.0; Lander et al, 1987) with the Kosambi function (Kosambi, 1944).…”

“…1) (Ohara et al, 2005a). The J map covered 1,068 cM with 16 linkage groups (J1-J16), and D map 1,104 cM with 15 linkage groups (D1-D15).…”

“…These QTLs are expected to be targets of marker-aided selection (MAS) for rapid seedling growth. We previously reported a cluster of distorted markers showing an excess of heterozygotes near AFS012 on D3, and speculated about the presence of loci related to heterosis or inbreeding depression (Ohara et al, 2005a). This speculation was strongly supported by the detection of a highly effective QTL in the proximity of AFS012 on D3 in the present study.…”

“…Recently, we developed simple sequence repeat (SSR) markers of bunching onion (Song et al, 2004), and constructed 2 linkage maps mainly based on amplified fragment length polymorphism (AFLP) markers using reciprocal backcrossed progenies (Ohara et al, 2005a).…”