Identification and comparative analysis of quantitative trait loci associated with parthenocarpy in processing cucumber

Abstract

Parthenocarpy (seedless fruit) is an economically important yieldrelated trait in cucumber (Cucumis sativus L.; 2n ¼ 2x ¼ 14). However, the genomic locations of factors controlling parthenocarpic fruit development in this species are not known. Therefore, an F 2 : 3 mating design was utilized to map quantitative trait loci (QTL) for parthenocarpy using a narrow cross employing two gynoecious, indeterminate and normal leaf lines [2A (parthenocarpic) and Gy8 (non-parthenocarpic)]. QTL detection was performed employing 2A-and Gy8-coupling phase data using the parthenocarpic yield of 126 F 3 families grown at two locations at Hancock, WI in 2000. The QTLs detected in this study were compared with the map locations of QTLs conditioning first-harvest yield of seeded cucumber characterized in a previous study. There were 10 QTLs for parthenocarpy detected defining four genomic regions, in which three QTLs also mapped to the same genomic regions as QTLs detected for fruit yield at first-harvest as reported in a previous study. The eight fluorescence amplified fragment length polymorphism (AFLP) markers linked to parthenocarpy through QTL mapping defined herein (four each in linkage groups 1 and 4) are candidates for use in marker-assisted selection programmes where breeding for increased levels of parthenocarpy is an objective in the elite-processing cucumber populations.

Analysis of generation means and components of variance for parthenocarpy in cucumber (Cucumis sativus L.)

“…This finding contrasts with those of Hawthorn and Wellington (1930) and Pike and Peterson (1969) who suggested that the inheritance of parthenocarpy in US processing cucumber is controlled by a single major gene. To gain more insight into the number of genes controlling parthenocarpy, a quantitative trait loci (QTL) analysis has recently been conducted that identified several genes (approximately 8 QTL) for parthenocarpy in the 2A × Gy8 population (Sun et al. 2006b).…”

Determination of Genetic Distance among Genotypes of Cucumber, Cucumis sativus L., Using ISSR Marks

“…[14,23,19] found the importance of using molecular DNA indicators in improving the quality and productivity of cucumber. [21,7,10,25] confirm the importance of molecular DNA indicators in forming genetic link maps of cucumber. [24] identifiedthe sites of genes, that responsible of parthenocarpy in cucumber, by using molecular DNA indicators.…”

Use of molecular markers aids in the development of diverse inbred backcross lines in Beit Alpha cucumber (Cucumis sativus L.)

“…Cucumber genetic maps have been constructed using narrow-and broad-based populations (Bradeen et al 2001;Fazio et al 2003;Sun et al 2006a;Yuan et al 2008). However, genetic mapping of economically important traits has not been performed using Beit Alpha cucumber germplasm.…”

“…Linkage groups F1, F2, F3, F4, F5, F6, and F6 are fromFazio et al (2003); linkage groups S1, S2, S3, S4, S5, S6, and S7 are fromSun et al 2006a; linkages groups Y1, Y2, Y3, Y4, Y5, Y6, and Y6 are fromYuan et al (2008) b BC 1 indicates markers used during the marker assisted selection (MAS) of the BC 1 generation c BC 2 indicates markers used during MAS of the BC 2 generation d Yes indicates the use of that marker during selection or evaluation, No indicates the exclusion of the marker e Expected allele frequency of the homozygous genotype of the recurrent parent in the BC 2 S 3 generation f Observed allele frequency towards the homozygous genotype of the recurrent parent at BC 2 S 3 generation…”