Multi-environment QTL mapping in blackcurrant (Ribes nigrum L.) using mixed models

Abstract

The first genetic linkage map of blackcurrant, published by Brennan et al. (Euphytica 161:19-34, 2008), identified regions where quantitative trait loci (QTLs) for some important traits were located. The analysis was complicated by the fact that the mapping population was found to contain two subgroups, with segregation ratios consistent with these being crossed and selfed offspring. The QTL analysis was based on the trait mean over 3 years and focused on the crossed offspring. Here we proposed a mixed model multi-environment approach for this population. The 3 years are considered as three separate environments, the data from both the selfed and crossed offspring are combined and different residual terms are explored to model the correlation between the years. This permits tests for interactions between the QTLs, the year and the type of offspring (selfed or crossed). This is applied to re-analyse two important traits, anthocyanin concentration and budbreak. Several additional QTLs were identified, some affecting the trait in both the selfed and crossed offspring, others in just one.

Genotype and microclimate conditions influence ripening pattern and quality of blackcurrant (Ribes nigrum L.) fruit

“…Thus, the growing conditions and microclimate have a larger effect on AsA content in 'Intercontinental' than in 'Titania'. Some researchers suggest that, although ascorbic acid content depends on the genotype, significant environmental effects have been noted in the level of ascorbic acid (Hancock et al, 2007;Pedersen, 2008;Brennan, Graham, 2009;Hackett et al, 2010). Our study revealed a strong negative correlation (r = −0.95) between average temperature in July and ascorbic acid content in the fruit.…”

Candidate genes associated with bud dormancy release in blackcurrant (Ribes nigrum L.)

“…In 2003, the LOD score for budbreak in this region was less than the usual threshold of 3.0, but the QTL effect was the same sign [ 15 ]. A more powerful QTL by environment (year) analysis of the combined 2003 and 2004 data [ 23 ] showed that SERB09L03 ( GT022654 ) and SERB03C05 ( GT027101 ) were significantly associated with budbreak (p-value < 0.001) and that there was no significant QTL by year interaction. The mean budbreak for the heterozygous genotype at these SNPs was 4.0 days (se 2.35) earlier than the homozygote in 2002 and 1.6 (se 0.84) earlier in 2003.…”

Polyphenol variability in the fruits and juices of a cider apple progeny

“…Numerous studies have focused on the genetic bases of phenolic compounds . Anthocyanins have been particularly well studied in fruits since they are major contributors to fruit quality . A cluster of three MYB genes involved in the anthocyanin content was identified following a quantitative trait locus (QTL) study on grape .…”