|May Iii, Oscar|
Submitted to: World Cotton Research Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/1998
Publication Date: N/A
Technical Abstract: Increased fiber strength is desirable to facilitate open-end yarn manufacture and textile performance. Improving fiber strength by conventional breeding has been successful, but biotechnology coupled with breeding offers the possibility of more immediate improvement. Monsanto Company is a leader in efforts to incorporate value added traits into cotton cultivars. As part of Monsanto's discovery program, coding sequences are isolated from various species, and then inserted into cotton via Agrobacterium or particle bombardment mediated transformation. Deltapine 50 (DP 50) plants with increased fiber strength were recently discovered after transformation by particle bombardment. The inserted sequences included a ubiquitous GUS marker gene, driven by the 35s CaMV promoter, and a proprietary plasmid containing a fiber specific promoter. Non-mendelian segregation for fiber strength and GUS were noted in some small R3 and R4 populations isolated from the original R0 plant. Thus, the objective of this study was to examine some large populations to determine the heritability and expression of fiber strength under field conditions. We examined heritability of fiber strength and GUS by self-pollinating R4 plants and outcrossing them to germplasms other than DP 50. In 1997, we evaluated the resulting progeny rows, F1s, F2s, and BC1F1s. Fiber strength of most GUS-positive plants was increased from 5-10 g/tex over DP 50. Non-mendelian segregation for GUS and fiber strength were noted in some progeny rows, BC1F1s, and F2s. A few lines appear to transmit strength and GUS to their progeny. Although no commercial product is imminent, we are continuing breeding efforts to isolate a germplasm with stable expression of increased strength.