A major quantitative trait locus for wheat total root length associated with precipitation distribution

Area of Science:

• Plant Genetics
• Crop Science
• Agricultural Biotechnology

Background:

• Optimizing root system architecture (RSA) is crucial for crop water and nutrient acquisition, especially in challenging environments.
• Parental reproductive environment (PRE) can significantly influence offspring growth and development.

Purpose of the Study:

• To identify quantitative trait loci (QTL) for root system architecture (RSA)-related traits in wheat.
• To investigate the genetic basis of total root length (TRL) and its potential for crop improvement.

Main Methods:

• Evaluated 10 RSA traits across five hydroponic tests using seeds from different PREs.
• Utilized a Wheat55K SNP array and a recombinant inbred line population to detect QTL.
• Developed and validated Kompetitive Allele-Specific PCR (KASP) markers for a major QTL.

Main Results:

• Detected 28 putative QTL for RSA traits across thirteen chromosomal regions.
• Identified a major QTL, QTrl.sicau-2SY-4D, on chromosome 4DS, explaining 15.81-38.48% of phenotypic variation for TRL.
• This QTL exhibited pleiotropic effects on multiple root and shoot traits and was validated in diverse genetic populations.

Conclusions:

• QTrl.sicau-2SY-4D is a significant and potentially valuable QTL for enhancing TRL in wheat breeding.
• The positive allele of this QTL is prevalent in wheat varieties from arid regions of Northwest China, suggesting its adaptive significance.
• Four candidate genes related to root development were identified within the QTL region.