Narrative
FA2/FA7/CU17NBL is a line derived in the CU17NBL acylsugar benchmark breeding line by transferring both the FA2 and FA7 containing introgressions into CU17NBL background. As shown by Leckie et al (2014), the FA2 QTL modifies the fatty acid chains of the acylsugars produced, increasing the length of branched chain fatty acids from the original 4 or 5 carbons, by 6 to 8 additional carbons. The FA7 QTL modifies the fatty acid chains of the acylsugars produced, decreasing the length of moderate length fatty acids from by 2 carbons.
The FA7QTL containing introgression was transferred into the prior benchmark line, CU071026, as described in Smeda et al (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).
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 1,445,344 bp in length
• Chromosome 10: the Chr10U introgression, from 0 - 1,916,909 bp: Therefore, it is 2,540,669 bp in length.
The additional introgressions of FA2/FA7/CU17NBL are:
• Chromosome 2: the FA2 introgression, from ca. 45,323,696 bp to 46,678,079 bp. Therefore, it is ca. 1,354,383 bp in length
• 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.