Comparative genetic analysis of quantitative traits in sunflower (Helianthus annuus L.). 2. Characterisation of QTL involved in developmental and agronomic traits

Abstract

Seed weight and oil content are important properties of cultivated sunflower under complex genetic and environmental control, and associated with morphological and developmental characteristics such as plant height or flowering dates. Using a genetic map with 290 markers for a cross between two inbred sunflower lines and 2 years of observations on F3 families, QTL controlling seed weight, oil content, plant height, plant lodging, flowering dates, maturity dates and delay from flowering to maturity were detected. QTL detected were compared between the F2 and F3 generations and between the 2 years of testing for the F3 families in 1997 and 1999. Some of the QTL controlling seed weight overlapped with those controlling oil content. Several other co-localisations of QTL controlling developmental or morphological characteristics were observed and the relationships between the traits were also shown by correlation analyses. The relationships between all these traits and with resistance to Sclerotinia sclerotiorum and Diaporthe helianthi are discussed.

Contributions of Flowering Time Genes to Sunflower Domestication and Improvement

“…Not all of the genes underlying detected QTLs are expected to have experienced the same selective pressures during either domestication or improvement, however. Genetic variation for flowering has been detected in crosses between elite lines (Leon et al 2000(Leon et al , 2001Bert et al 2003), and different lines may have different recent histories of selection on flowering time by farmers in different geographic regions. This scenario would increase diversity and obscure a signature of selection.…”

Changes in antioxidant systems in sunflower partial resistant and susceptible lines as affected by Sclerotinia sclerotiorum

“…In Iran, infections of the sunflower basal stem are considered a potential threat to the entire crop. Earlier studies suggested that inheritance of resistance to S. sclerotiorum is polygenic and partial resistance to S. sclerotiorum involves many genes, each of them singly makes a relatively small contribution to the overall resistance (Castano et al 1993;Bert et al 2004). Using parental lines and their recombinant inbred lines, Davar et al (2010) identified several quantitative trait loci for partial resistance to S. slerotiorum under controlled conditions.…”

Testing sunflower inbred lines for tolerance to Phoma black stem

“…Darvishzadeh et al (2010) found the inbred lines F1250/03, M5-54-1, M6-862-1, two wild accessions and two lines developed by mutagenesis to be tolerant. Although tolerant genotypes were identified, full resistance was not found (Roustee et al, 2000a;Bert et al, 2004).…”