New QTLs for lint percentage and boll weight mined in introgression lines from two feral landraces into Gossypium hirsutum acc TM‐1

Abstract

Overuse of a small number of Upland cotton cultivars has narrowed cotton's genetic base, leading to major difficulties in developing cotton cultivars with diverse genetic backgrounds that are able to adapt to adverse conditions. To effectively broaden the genetic base, chromosome introgression lines (ILs) were developed, where TM‐1, the genetic standard of Upland cotton, was used as the common recipient and its two feral landraces, TX‐256 and TX‐1046, were used as the donors. A total of 115 ILs, with an average segment length of 11.15 cM, were first developed via intraspecific hybridization by marker‐assisted selection (MAS) in BC3F2 generations, spanning 3887.75 cM of the cotton genome. Association analysis showed that 63 markers were found to be associated with boll weight (BW), lint percentage (LP) and seed index. The percent of phenotypic variance explained by 148 QTLs detected was 4.12% on average. Eleven and five new QTLs for BW and LP (one stable QTL identified for LP in all environments) were detected, respectively, which can be used for efficiently pyramiding favourable alleles into one cultivar by MAS.

Mapping of fiber quality QTLs reveals useful variation and footprints of cotton domestication using introgression lines

“…Interestingly, compared the yield-related trait QTLs detected in more than three environments, we also found that the number of QTLs showing negative effects on fiber yield-related traits is much more than that of QTLs showing positive effects (25 negative QTLs:15 positive QTLs) ( Supplementary Information Table S1 ). When comparing our results with those of our previous report 17 , and a report by Said et al . 13 on intraspecific and interspecific populations, for example, we found that seven qBWs, five qLPs and five qSIs had never been reported before.…”

“…The total length of introgression segments of the 66 ILs derived from TX-256 was 1,104.15 cM, which accounted for 28.40% of the whole introgression fragment. The length of the introgression fragments of 49 ILs from TX-1046 was 2,783.60, accounting for 71.60% of the whole introgression fragment17. Here, both the joint genetic linkage map and 115 ILs were employed to map QTLs of fiber quality traits.…”

“…These traits are also affected by biotic stressors, including premature senescence, Verticillium wilt, insects and weeds, and by abiotic stress conditions, including flooding, extreme temperatures and drought 11 12 . Researchers have detected QTLs associated with fiber properties from both intraspecific populations of G. hirsutum and interspecific crosses between G. hirsutum and G. barbadense , as well as their later generations 13 14 15 16 17 . At the same time, the large number of differentially expressed genes highlights the complex alteration of global gene expression machinery that resulted from human selection of a longer, stronger, and finer fiber.…”

Genetic Mapping in Cotton

“…Zhang et al [127] developed chromosome introgressed lines using TM-1 and TX-256 and TX-1046 and observed 5 QTLs related to ginning out turn and concluded 1 stable QTL which was observed in multiple environments.…”

“…Zhang et al [127] observed QTLs related to fiber length, micronaire and strength using SSR and SNPs in a RIL population consisted of 196 individuals developed from 0 to 153 and sGK9708. They identified 25 QTLs on chromosome 25 and 17 among them were common in minimum two locations.…”