Author
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Knepper, Caleb |
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Mou, Beiquan |
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Submitted to: Journal of Visualized Experiments
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/30/2014 Publication Date: 4/27/2015 Citation: Knepper, C.P., Mou, B. 2015. Semi-high throughput screening for potential drought-tolerance in lettuce (Lactuca sativa) germplasm collections. Journal of Visualized Experiments. (98):e52492. doi: 10.3791/52492. Interpretive Summary: Fresh water availability for agricultural use is an urgent and growing concern across the United States as well as many regions of the world. Short term drought events along with regulatory intervention in the regulation of water availability coupled with the looming threat of long-term climate changes that may lead to reduced precipitation in many important agricultural regions has increased the need to hasten the development of crops adapted for improved water use efficiency in order to maintain or expand production in the coming years. This article describes a method by which a large collection of the lettuce (Lactuca sativa L.) varieties was screened for drought-tolerance traits. This paper is not meant as a step-by-step guide to identifying at either the physiological or molecular level drought-tolerance traits in lettuce, but rather represents a method developed and refined through the screening of thousands of different lettuce varieties. The nature of this screen is based in part on the streamlined measurements focusing on only three water-stress indicators including leaf relative water content, wilt, and differential plant growth following drought-stress. The purpose of rapidly screening a large lettuce collection is to narrow the candidate pool to a manageable number of varieties to which more intensive physiological, molecular, and genetic methods can be applied to identify specific drought-tolerant traits in either the lab or field. Candidates identified can also be directly incorporated into breeding programs as a source of drought-tolerance traits. Although the protocol as presented was developed and adapted to lettuce, it has been successfully adapted for use in a screen for drought-tolerance in spinach (Spinacia oleracea) and could be modified simply to screen any leafy vegetable crop. Technical Abstract: This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of the world. Short term drought events along with regulatory intervention in the regulation of water availability coupled with the looming threat of long-term climate shifts that may lead to reduced precipitation in many important agricultural regions has increased the need to hasten the development of crops adapted for improved water use efficiency in order to maintain or expand production in the coming years. This protocol is not meant as a step-by-step guide to identifying at either the physiological or molecular level drought-tolerance traits in lettuce, but rather is a method developed and refined through the screening of thousands of different lettuce varieties. The nature of this screen is based in part on the streamlined measurements focusing on only three water-stress indicators: leaf relative water content, wilt, and differential plant growth following drought-stress. The purpose of rapidly screening a large germplasm collection is to narrow the candidate pool to a point in which more intensive physiological, molecular, and genetic methods can be applied to identify specific drought-tolerant traits in either the lab or field. Candidates can also be directly incorporated into breeding programs as a source of drought-tolerance traits. |
