Identification of Spring Wheat with Superior Agronomic Performance under Contrasting Nitrogen Managements Using...

Area of Science:

• Plant breeding and genetics
• Agricultural science
• Quantitative genetics

Background:

• Linear Phenotypic Selection Index (LPSI) and Restrictive Linear Phenotypic Selection Index (RLPSI) are established methods for parent and progeny selection.
• The influence of economic weights on selection parameters like genetic gain and response to selection requires detailed investigation.

Purpose of the Study:

• To assess the impact of economic weights on selection parameters using multi-trait indices.
• To compare single-trait versus multi-trait selection indices (LPSI and RLPSI) under varying management conditions.
• To identify superior spring wheat cultivars for organic and conventional farming systems.

Main Methods:

• Evaluated 2304 economic weight combinations across four traits (maturity, plant height, grain yield, grain protein content).
• Compared single-trait and multi-trait selection indices (LPSI vs. RLPSI) with restrictions on expected genetic gain for yield or grain protein.
• Assessed cultivar performance across four organic (low nitrogen) and five conventional (high nitrogen) environments.

Main Results:

• Multi-trait selection indices outperformed single-trait indices.
• Selection parameters varied significantly based on economic weights, highlighting the need for optimization.
• Twenty-two superior spring wheat cultivars were consistently identified across multiple selection scenarios and economic weights.

Conclusions:

• Economic weight optimization is essential for effective multi-trait selection in spring wheat breeding.
• The identified superior cultivars are valuable for breeding programs, particularly for organic systems and nitrogen use efficiency studies.
• This research provides insights into optimizing selection strategies for diverse agricultural management systems.