International Journal of Plant Genomics 
Volume 2007 (2007), Article ID 97386, 10 pages
doi:10.1155/2007/97386
Research Article

Common QTL Affect the Rate of Tomato Seed Germination under Different Stress and Nonstress Conditions

Majid R. Foolad, Prakash Subbiah, and Liping Zhang

 Department of Horticulture and The Intercollege Graduate Degree Programs in Genetics and Plant Biology, The Pennsylvania State University, University Park 16802, PA, USA
Received 21 August 2007; Accepted 24 November 2007

Recommended by Hikmet Budak

Abstract

The purpose of this study was to determine whether the rates of tomato seed germination under different stress and nonstress conditions were under common genetic controls by examining quantitative trait loci (QTL) affecting such traits. Seeds of BC1 progeny of a cross between a slow-germinating tomato breeding line and a rapid-germinating tomato wild accession were evaluated for germination under nonstress as well as cold, salt, and drought stress conditions. In each treatment, the most rapidly-germinating seeds were selected, grown to maturity, and subjected to molecular marker analysis. A selective genotyping approach detected between 6 and 9 QTL affecting germination rate under each of the four conditions, with a total of 14 QTL identified. Ten QTL affected germination rate under 2 or 3 conditions, which were considered germination-related common QTL. Four QTL affected germination rate only in one treatment, which were considered germination-related, condition-specific QTL . The results indicated that mostly the same QTL affected seed germination under different stress and nonstress conditions, supporting a previous suggestion that similar physiological mechanisms contribute to rapid seed germination under different conditions. Marker-assisted selection for the common QTL may result in progeny with rapid seed germinability under different conditions.