Freeze response indicators in sugarcane (Saccharum spp. hybrids)

Area of Science:

• Agricultural Science
• Plant Biology
• Biochemistry

Background:

• Extreme weather events, such as the 2022 winter freeze and 2023 summer drought in the Southern U.S., highlight the need for climate-resilient sugarcane varieties.
• Current sugarcane breeding programs lack specific genetic markers for cold tolerance, relying on post-freeze damage assessments.

Purpose of the Study:

• To identify quantitative markers for freeze damage in sugarcane.
• To develop novel chemical phenotyping approaches for assessing cold tolerance in sugarcane.

Main Methods:

• Cluster analysis was used to identify potential freeze damage markers, including fluorescent amino acids.
• Fluorescence microscopy and fluorescent nanoparticles were employed to visualize cellular markers in sugarcane fiber components.
• Comparative analysis of sugarcane cultivars under freeze conditions.

Main Results:

• The sugarcane cultivar HoCP 04-838 demonstrated significantly higher tolerance to freeze damage, exhibiting 3-5 fold lower stalk fracture.
• This tolerant variety contained high fiber content and showed the lowest particulate juice decomposition byproducts (p<0.05).
• Fluorescent markers, associated with lipids and hydrophobic components, were visualized in lignin cells around vascular bundles of the tolerant cultivar.

Conclusions:

• Fluorescence-based cellular markers in sugarcane fiber can effectively assess cold tolerance.
• Developed chemical phenotyping methods offer a more efficient alternative to traditional post-freeze damage assessment for sugarcane breeding.
• This research facilitates the expedited release of climate-resilient sugarcane varieties.