Author
LONGENBERGER, P - TEXAS A&M UNIVERSITY | |
SMITH, C - TEXAS A&M UNIVERSITY | |
THAXTON, P - TEXAS A&M UNIVERSITY | |
McMichael, Bobbie |
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/4/2006 Publication Date: 9/8/2006 Citation: Longenberger, P.S., Smith, C.W., Thaxton, P., McMichael, B.L. 2006. Developemnt of a screening method for drought tolerance in cotton seedlings. Crop Science. 46:2104-2110. Interpretive Summary: The development of efficient screening methods for evaluating large amounts of plant material for various traits such as drought tolerance is critical for advancing the development of improved varieties. A rapid screening method was developed for evaluating cotton seedlings for differences in drought tolerance under controlled environment conditions. Seedlings were subjected to three drought cycles where water was withheld until a predetermined soil water content was reached after which the plants were rewatered and the survival of the seedlings evaluated. It was determined that one drought cycle was sufficient for separating the germplasm as to the ability to survive. The utility of the screening method will be further assessed in forthcoming field studies where plants are subjected to similar drought conditions. Technical Abstract: The key to an efficient screening method is the ability to screen large amounts of plant material in the shortest time possible. Unfortunately, due to the complexity of drought tolerance, a quick and effective screen for this trait has yet to be established. The research reported herein was designed to evaluate a screening method for drought tolerance in cotton (Gossypium hirsutum L.) seedlings. Twenty-one converted race stocks (CRS) and two cultivars were evaluated for seedling drought tolerance (SDT) on an individual plant basis. CRS are day-sensitive primitive wild race stock lines that were converted to day neutrality for use in temperate region plant improvement programs (McCarty et al., 1993). Genotypes were evaluated October – November 2004 and February – March 2005 under greenhouse conditions at the Norman E. Borlaug Center for Southern Crop Improvement, College Station, TX. Seedlings were subjected to three sequential cycles of drought at 15 days after planting (DAP). Drought cycles consisted of withholding water until the moisture content of “indicator” ‘Deltapine 491’ (DP 491) plants, had an average volumetric water content of 0.07. Plants were then watered to saturation and allowed to drain to field capacity and percent survival recorded after 48 hours. Genotypes differed in their percent survival following three consecutive drought cycles. Drought cycles 2 and 3 did not contribute to the separation of genotypes. DP 491 was the most tolerant genotype evaluated. The CRS did not differ in drought tolerance with ‘Acala 1517-99’. CRS M-9044-0165 was the most stable genotype across the two experiments. |