|KOTHARI, NEHA - Texas Agrilife Research|
|Campbell, Benjamin - Todd|
|DEVER, JANE - Texas Agrilife Research|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2015
Publication Date: 12/30/2015
Citation: Kothari, N., Campbell, B.T., Dever, J.K., Hinze, L.L. 2015. Combining ability and performance of cotton germplasm with diverse seed oil content. Crop Science. 56:19-29.
Interpretive Summary: In the US, cotton yield has improved dramatically over the last few decades as the result of breeding and management techniques. In contrast, oil content of cotton seeds has stagnated during this time even though researchers have voiced the importance of developing cotton with higher oil and protein content to address long-term nutrition and food supply needs. The current study addresses whether oil content has the potential for genetic improvement through breeding by evaluating the performance of several types of cotton and their combinations. This study shows that high and low values for seed oil content can be transferred from parents to their progeny in a breeding program. In addition, there is sufficient genetic diversity to improve this trait even further than what is seen in current commercial cotton. Oil content can be increased at the same time as important fiber traits including length and strength to produce cotton with economically important traits. However, environmental conditions can interfere with genetic improvement efforts. Cottonseed oil has tremendous potential in our food network because it is high in healthy unsaturated fats, primarily linoleic acid, and does not break down as easily as other vegetable oils during cooking and frying. We have shown that cottonseed oil content can be increased, thus enhancing the food nutritive value of cotton for consumers, and raising its economic value for producers in the US and worldwide.
Technical Abstract: A line by tester analysis was used to identify superior general and specific combining parents for seed oil content in upland cotton (Gossypium hirsutum L.). This experiment was conducted using four lines (PD 7723, PD 94042, PD 3246 and PD 5377) and four testers (TX 21, TX 101, TX 182 and TX 244) with varying seed oil content selected from accessions in the U.S. National Cotton Germplasm Collection. Combining abilities were determined by crossing the four lines and four testers to develop the sixteen hybrids evaluated here. Seed oil content was found to be a heritable trait (H2 = 0.52). Overall, TX 182 and TX 101 had higher combining abilities while PD 94042 had the lowest combining ability for oil content. Among hybrid combinations, PD 3246 * TX 101, PD 7723 * TX 101 and PD 5377 * TX 182 had the highest combining abilities while hybrids with the PD 94042 parent yielded lowered combining abilities. All traits tested in these environments showed highly significant genotype by environment effects. The highest mean oil was observed in Florence, SC during 2010 (TX 182, 28.28%). This study shows that there is sufficient additive variance available for plant breeders to improve seed oil content. In addition, correlation analyses indicated that oil content can be increased at the same time as seed index, boll size and fiber traits including elongation, uniformity, upper half mean length and strength.