Author
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KLOTH, REINER - ORCHID BREEDER SELF EMPLO |
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Submitted to: Euphytica
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/9/2008 Publication Date: 11/24/2008 Citation: Kloth, R.H. 2008. The Inheritance Model for the Fiberless Trait in Upland Cotton (Gossypium Hirsutum L.) Line SL 1-7-1: Variation on a Theme. Euphytica. 164 :123-132 Interpretive Summary: Cotton fiber is the most important economic component in cotton production. Increased yield of cotton fiber is needed to make cotton a profitable crop in the USA. A fiberless experimental line (a line which does not produce cotton fiber) was crossed with fiber producing cotton lines and their descendants were evaluated. We discovered that the lack of fiber production was controlled by at least three genes. We will determine how these genes function to limit production of cotton fibers, and we then hope to increase the activity of the normal (non mutant) genes to increase fiber production, making cotton a more profitable crop for USA cotton grower Technical Abstract: Segregating populations were developed to evaluate the inheritance of the fiberless seed phenotype of upland cotton (Gossypium hirsutum L.) line SL 1-7-1. We report the inheritance of fuzzy, fuzzless and fiberless seed from crosses of SL 1-7-1 with wildtype DP 5690, Mexican fuzzless seed UA 3-3 (accession 143), Ballard fuzzless seed (accession 243) and MD 17 fiberless. Results from the F1, F2 and F2:3 progeny derived from the SL 1-7-1 X DP 5690 indicated that the expression of the fiberless phenotype fit a three loci model and that SL 1-7-1 was homozygous for the dominant fuzzless seed allele N1. The other two loci involved in the expression of the fiberless phenotype of SL 1-7-1 were evaluated for the presence of the recessive fuzzless seed alleles n2 and n3. F2- derived F3 families from SL 1-7-1 X DP 5690 with fuzzy seed (lacked N1) were deficient in at least one of the recessive fuzzless seed alleles n2 or n3. Absence of n2 or n3 in the SL 1-7-1 genotype was confirmed in the F2 population of the 143 X SL 1-7-1 cross. The homozygous expression of the one non-characterized locus in the SL 1-7-1 line does not produce progeny with a fuzzless seed coat, therefore, it is not classified as a fuzzless seed allele. We have designated this allele as en1, or recessive enhancer of N1. A putative inhibitor for en1 was also found in line 243 and MD 17 which we have designated Lp1. The expression of the fuzzless N1 and n2, along with the non fuzzless seed allele en1 produced plants with much lower lint percents. A comparison of the genotypes of SL 1-7-1 has allowed us to propose a common theme for the production of fiberless cotton. Three of the four fiberless lines described in the literature possess at least one of the fuzzless seed alleles, SL 1-7-1 (N1), MD 17 fiberless (N1 and n2) and XZ142w (n2). |
