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United States Department of Agriculture

Agricultural Research Service

Title: DNA Markers Linked to Ligon Lintless (Li1) Mutant in Cotton

Authors
item Karaca, Mehmet - MISSISSIPPI STATE UNIV
item Saha, Sukumar
item Jenkins, Johnie
item Zipf, Allan - ALABAMA A&M UNIVERSITY
item Kohel, Russell
item Stelly, David - TEXAS A&M UNIVERSITY

Submitted to: Journal of Heredity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 13, 2002
Publication Date: October 1, 2002
Citation: KARACA, M., SAHA, S., JENKINS, J.N., ZIPF, A., KOHEL, R.J., STELLY, D. Simple sequence repeat (SSR) markers linked to the ligon lintless (li1) mutant in cotton. JOURNAL OF HEREDITY. 2002. v.93.p.221-224.

Interpretive Summary: Identification of a locus specific to fiber development is an important step toward manipulation and improvement of cotton fiber properties. Ligon lintless (Li1) is a monogenic, novel dominant mutant in cotton, whose expression results in extreme reductions in fiber length on mature seed. This mutant is especially important considering the fact that fiber price in textile industries is dependent on the content of short versus long fibers in a cultivar. The objectives of this research were to: (1)utilize the Li1 mutant to understand fiber initiation; (2) develop a linkage map of Simple Sequence Repeat Length Polymorphisms (SSRLPs) markers with Li1 locus, and (3)determine the chromosomal location of Li1 locus based on marker-assisted identification. Scanning Electron Microscopy (SEM) results demonstrated that there were no differences between TM-1 and Li1 at fiber initiation indicating that the genetic control of fiber initiation was very similar between both lines. This suggested that no phenotypic effects of Li1 on fiber initiation, however, Li1 showed effects on fiber elongation. A total of 22 SSRLP loci and the Li1 locus were found to be linked on 8 linkage groups (LNK) covering a total distance of 218.3 cM. LNK-1 consisted of Li1 and the MP4030-113, MP673-189, MP530-142, and MP3994-94 loci. MP4030-113 and MP673-189 loci linked to Li1 were located on the short arm of chromosome 22. This research first identified DNA markers linked to Li1 and its location on chromosome 22. This is the first morphological marker assigned to chromosome 22.

Technical Abstract: Ligon lintless (Li1) is a monogenic, novel dominant mutant in cotton whose expression results in extreme reductions in fiber length on mature seed. A DNA marker linked to Li1 locus provides a valuable tool for the identification of fiber elongation factor(s). The objectives of this research were to: (1) utilize the Li1 mutant to understand fiber initiation; (2) develop a linkage map of Simple Sequence Repeat Length Polymorphisms (SSRLPs) markers with Li1 locus, and (3) determine the chromosomal location of Li1 locus based on marker-assisted identification. Scanning Electron Microscopy (SEM) studies of fiber number and fiber development in a normal, TM-1, genotype and the near isogenic Li1, mutant at 1 and 3 days post anthesis (dpa) revealed little difference in the two at early stages of development. Similarity of early development in normal and mutant genotypes suggests that Li1 gene expression occurs in later stage of development, probably during the elongation phase. In efforts to map the location of Li1 within linkage groups, 38 SSRLP loci were found to be polymorphic between TM-1 and Li1 and suitable for mapping using an F2 population. Of these loci 22 SSRLP loci along with Li1 were located on 8 linkage groups covering a total genetic distance of 318.3 cM. Li1 was closely linked with SSRLP locus MP4030-113 at a distance of 12.8 cM and two SSRLP loci from the Li1 linkage group (LNK-1) were located on the short arm of chromosome 22 suggesting that it is also located on this chromosome arm.

Last Modified: 10/26/2014
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