Combining NDVI and Bacterial Blight Score to Predict Grain Yield in Field Pea

Abstract

Field pea is the most commonly grown temperate pulse crop, with close to 15 million tons produced globally in 2020. Varieties improved through breeding are important to ensure ongoing improvements in yield and disease resistance. Genomic selection (GS) is a modern breeding approach that could substantially improve the rate of genetic gain for grain yield, and its deployment depends on the prediction accuracy (PA) that can be achieved. In our study, four yield trials representing breeding lines' advancement stages of the breeding program (S0, S1, S2, and S3) were assessed with grain yield, aerial high-throughput phenotyping (normalized difference vegetation index, NDVI), and bacterial blight disease scores (BBSC). Low-to-moderate broad-sense heritability (0.31–0.71) and narrow-sense heritability (0.13–0.71) were observed, as the estimated additive and non-additive genetic components for the three traits varied with the different models fitted. The genetic correlations among the three traits were high, particularly in the S0–S2 stages. NDVI and BBSC were combined to investigate the PA for grain yield by univariate and multivariate GS models, and multivariate models showed higher PA than univariate models in both cross-validation and forward prediction methods. A 6–50% improvement in PA was achieved when multivariate models were deployed. The highest PA was indicated in the forward prediction scenario when the training population consisted of early generation breeding stages with the multivariate models. Both NDVI and BBSC are commonly used traits that could be measured in the early growth stage; however, our study suggested that NDVI is a more useful trait to predict grain yield with high accuracy in the field pea breeding program, especially in diseased trials, through its incorporation into multivariate models.

Breeding for Biotic Stress Resistance in Pea

“…Implementation of GS approaches to improve biotic stresses in pea is only initiating, and very few reports are available so far on the development of GS models for disease resistance. Efforts have been made to produce the first GS models for resistance to ascochyta blight [194], bacterial blight [195], or rust [196]. Implementation of GS techniques is expected to steadily increase as genotyping costs decrease.…”

The Exceptionally Large Genomes of the Fabeae Tribe: Comparative Genomics and Applications in Abiotic and Biotic Stress Studies

“…Other studies on biotic stresses have been taking advantage of the Caméor pea genome availability, such as studies on resistance against insects [82,83], the parasitic plant Orobanche crenata [20], herbivores [84], and bacterial blight [97]. In these studies, the pea genome was useful for genotyping using the genome as a reference in GWAS for pea resistance to aphids [82]; comparative mapping between a high-density genetic map and the pea genome for genetic dissection of pea resistance to broomrape (Orobanche crenata) [20]; identification of candidate genes related to pea response to bruchid and herbivores [83,84]; and prediction of grain yield for field pea using bacterial blight disease scores [97]. The ZW6 pea genome was used in a comprehensive dataset of full-and partial-length NLR (nucleotide-binding leucine-rich repeat immune receptors) resistance genes across 100 chromosome-level plant genomes [98].…”

Genomic prediction and selection response for grain yield in safflower

“…Multivariate models showed higher prediction accuracy than univariate models in GS studies ( Jia and Jannink, 2012 ; Sun et al, 2019 ). The additional information in genetically correlated traits is exploited in multivariate models, and the higher the correlation is, the greater the multivariate models would benefit ( Zhao et al, 2022a ). Rutkoski et al (2016) included canopy temperature and normalized difference vegetation index in a multivariate model, which resulted in a 70% prediction accuracy improvement for grain yield in wheat.…”