Narrative
FA7/CU17NBL is a line derived in the CU17NBL acylsugar benchmark breeding line by transferring the FA2 introgression into CU17NBL. The FA7 QTL modifies the fatty acid chains of the acylsugars produced, decreasing the length of moderate length fatty acids from by 2 carbons.
1. Leckie, BM, R Halitschke, DM De Jong, JR Smeda, A Kessler, and MA Mutschler 2014. Quantitative trait loci regulating the fatty acid profile of acylsugars in tomato, Molecular Breeding: 34 (3) pp 1201-1213. The impact of FA2 on the fatty acids of acylsugars is to increase the length of branched chain fatty acids, which are typically 4 or 5 carbons, by 6 to 8 carbons
The FA7QTL containing introgression was transferred into the prior benchmark line, CU071026, as described in Smeda, 2016, and the epistatic interaction of FA7 with the FA2 QTL, which also affects acylsugar fatty acid side chains, was described in Smeda et al 2017.
1. Smeda JR, AL Schilmiller, RL Last, MA Mutschler. 2016 Introgression of acylsugar chemistry QTL modifies the composition and structure of acylsugars produced by high-accumulating tomato lines." Molecular Breeding. DOI 10.1007/s11032-016-0584-6
2. Smeda JR., AL Schilmiller, A Kessler, MA Mutschler 2017. Combination of QTL Affecting Acylsugar Chemistry Reveals Additive and Epistatic Genetic Interactions to Increase Acylsugar Profile Diversity. Molecular Breeding: 104 DOI 10.1007/s11032-017-0690-0
The creation of the major Cornell acylsugar lines including CU071026 and CU17NBL is reviewed in the publication by Mutschler (2021).
CU17NBL has 5 S. pennellii introgressions which combined are ca. 11% of the CU17NBL genome. The locations and sizes of these locations using the 2.5 genome build are:
• Chromosome 2: the Chr2 introgression, from 53,792,960 - 55,238,304 bp: Therefore, it is 1,445,344 bp in length.
• Chromosome 3: the Chr3 introgression, from 2,143,744 - 64,451,474 bp: Therefore, it is 62,307,730 bp length.
• Chromosome 7: the Chr7 introgression, from 65,554,074 – 65,801,666 bp: Therefore, it is 247,592 bp in length.
• Chromosome 8: the Chr8 introgression, from 60,843,834 – 63,384,503 bp: Therefore, it is 2,540,669 bp in length
• Chromosome 10: the Chr10U introgression, from 0 - 1,916,909 bp: Therefore, it is 1,916,909 bp in length.
The additional introgression of FA7/CU17NBL is:
• Chromosome 7: the FA7 introgression, from ca. 56,725,136 bp to 59,231,709 bp. Therefore, it is ca. 2,506,573 bp in length.
A variant of the FA7/CU17NBL line, named FA2/FA7/CU17NBL, was also created that is the same as FA7/CU17NBL except that also has a chromosome 2 introgression containing the FA2 QTL that also affects the fatty acid side chains of acylsugars. Seed of FA2/FA7/CU17NBL has also been deposited.
The source of the FA2QTL and the FA7 QTL containing introgressions to create FA2/CU17NBL and FA2/FA7/CU17NBL lines was the analogous line in CU071026 line, FA2/FA7/CU071026.
The FA7/CU17NBL line is very similar in acylsugar level and acylsugar types to that of its analogous line in CU071026 background: FA7/ CU071026. A publication regarding creation and complete characterizations of QTL6/CU17NBL and QTL6/Sw-5/CU17NBL, and other variant lines in CU17NBL is in preparation.