Genome wide selection in Citrus breeding.

Area of Science:

• Plant breeding
• Genomics
• Quantitative genetics

Background:

• Genomic wide selection (GWS) is crucial for accelerating genetic improvement in perennial crops like Citrus.
• It enhances selection efficiency, particularly for traits with low heritability, and increases gain per unit time.

Purpose of the Study:

• To evaluate the efficiency of GWS in a Citrus population.
• To compare GWS performance against traditional phenotypic selection.
• To assess GWS for early and accurate phenotype prediction in Citrus breeding.

Main Methods:

• Genotyping of 180 Citrus hybrids using 5287 DArT-seq molecular markers.
• Phenotypic evaluation of 10 fruit quality traits.
• Prediction of marker effects on phenotypes using random regression - best linear unbiased predictor (rr-BLUP).
• Estimation of predictive ability, bias, and accuracy of GWS.

Main Results:

• Marker-based heritability for traits ranged from 16-28%.
• GWS predictive ability was 0.53–0.64, with regression coefficients near unity.
• Markers explained over 35% of the genetic variance.
• GWS showed lower accuracy than phenotypic selection but superior genetic gain per unit time.

Conclusions:

• Genomic wide selection is feasible and effective for Citrus breeding.
• GWS facilitates early and accurate phenotype prediction, shortening the breeding cycle.
• This approach offers significant advantages for improving perennial species like Citrus.