Major Quantitative Trait Loci Control Low-Temperature Germination in Lettuce.

Area of Science:

• Plant genetics
• Crop science
• Agricultural biotechnology

Background:

• Low-temperature stress during germination hinders lettuce establishment, impacting yield and uniformity.
• Understanding the genetic basis of cold germination is crucial for improving crop resilience.

Purpose of the Study:

• Investigate the genetic architecture of cold germination in lettuce.
• Identify genomic regions and candidate genes controlling cold germination ability.

Main Methods:

• Utilized a biparental recombinant inbred line population from a cross between *Lactuca sativa* and *Lactuca serriola*.
• Performed quantitative trait locus (QTL) analysis to identify genomic regions associated with cold germination.

Main Results:

• Identified two significant genomic regions associated with cold germination, explaining 35% of phenotypic variance.
• Cultivated lettuce showed superior cold germination compared to wild lettuce.
• Candidate genes involved in hormone signaling and stress response were identified in the QTL regions.

Conclusions:

• Cold germination in lettuce is a genetically complex trait influenced by domestication and breeding.
• The identified genomic regions and candidate genes provide targets for marker-assisted breeding.
• Improving cold germination can enhance lettuce seedling establishment and extend cultivation into cooler environments.