QTL Mapping of Zeaxanthin Content in Sweet Corn Using Recombinant Inbred Line Population across Different...

Area of Science:

• Plant genetics
• Nutritional science
• Agricultural science

Background:

• Zeaxanthin, a xanthophyll carotenoid, is abundant in dietary sources like sweet corn.
• Understanding the genetic regulation of zeaxanthin content is crucial for crop improvement.

Purpose of the Study:

• To investigate the genetic basis of zeaxanthin content regulation in sweet corn.
• To construct a genetic map and identify quantitative trait loci (QTLs) associated with zeaxanthin accumulation.

Main Methods:

• A recombinant inbred line (RIL) population of 191 families was developed from two inbred lines with contrasting zeaxanthin levels.
• Zeaxanthin content was quantified using high-performance liquid chromatography (HPLC).
• A linkage map was constructed using 175 polymorphic simple sequence repeat (SSR) markers.

Main Results:

• Eight QTLs controlling zeaxanthin content were identified on chromosomes 4, 5, 7, 9, and 10.
• A major QTL on chromosome 7 (umc1632-umc1401) was consistently detected across environments, explaining 11.28–20.25% of phenotypic variation.
• This major QTL is implicated as the primary genetic factor regulating zeaxanthin content in sweet corn grains.

Conclusions:

• The study established a genetic map for sweet corn and identified key QTLs for zeaxanthin content.
• These findings offer valuable genetic insights and theoretical guidance for breeding sweet corn varieties with enhanced zeaxanthin levels.
• This research supports the development of nutritionally improved sweet corn through targeted genetic selection.