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ARS Home » Southeast Area » Charleston, South Carolina » Vegetable Research » Research » Publications at this Location » Publication #86130
Title: NUCLEAR DNA CONTENT AMONG SWEETPOTATO CULTIVARS AND RELATED IPOMOEA SPECIES IN SECTION BATATAS

Author
item Bohac, Janice
item AUSTIN, DANIEL - FLORIDA ATLANTIC UNIV.
item KRAMER, RAMONA - CLEMSON UNIVERSITY

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: The sweetpotato is a crop affected by many diseases and insects and has limitations in where it is grown because of lack of tolerance to environmental conditions like cold and wet soils. It has many wild relatives that are a resource for genes for pest resistance and resistance to environmental stress. Also many of these wild species make important compounds of potential use as natural pesticides or pharmaceutical use. However, one of the barriers to using these wild relatives for sweetpotato improvement is that the sweetpotato has 90 chromosomes, and the wild relatives have 30 to 60 chromosomes. There are methods to increase the chromosome numbers of these species. What is needed is a rapid method to screen large number of seedling lines rapidly and accurately. This work describes such a method using a specific stain for DNA. The amount of DNA stain measured was found to correlate well with the chromosome number for sweetpotato and the wild relatives.

Technical Abstract: A method was developed to utilize DNA flow cytometry for determination of the ploidy of sweetpotato - Ipomoea batatas (L). Lam. - and members of the Ipomoea family without the use of chromosome counting. This method used an enzymatic pretreatment of leaves followed by isolation of nuclei and staining with propidium iodide (PI). The method was altered until consistent results were obtained with standards (chicken red blood cells (CRBC), diploid I. trifida, tetraploid I. batatas, and hexaploid I. batatas). The method was used to determine the relative DNA content of Ipomoea species within the group Batatas. These results were compared to representative Ipomoea species outside the group Batatas, and non-Ipomoea species within Convolvulaceae. There was found to be linear relationship between DNA content and ploidy between sweetpotato and its closest Ipomoea relatives, diploid I. trifida and tetraploid I. batatas.