Heritability estimates in contrasting environments as influenced by the adaptation level of barley germ plasm

Abstract

Low heritability estimates in marginal or stress environments have often been used as one of the main justification for conducting selection work in environments with optimum or near‐optimum conditions for plant growth and grain yield. In this study, we have examined the relationships between grain yield and broad‐sense heritability in four groups of recombinant inbred lines (RILs) obtained from four barley crosses derived from parents differing in adaptation to stress. The RILs and the parents were grown in 13 combinations of years and locations (environments) in Syria and Jordan. Grain yields ranged from about 30 kg ha−1 to nearly 4000 kg ha−1 and genotype × environment interactions explained about half of the total variance for environmentally standardised data. Broad‐sense heritability in the individual year–location combinations varied from 0 to 0.68 and both the simple correlation and the rank correlation coefficients between grain yield and heritability were not significant. Genotype × years within individual locations, which measures the repeatability of a location in discriminating between genotypes, was also independent from the yield level, confirming that low‐yielding locations can be reliable selection environments. Also, there was no relationship between the type of cross and the magnitude of heritability in the various environments, but, as expected, the magnitude of heritability was significantly associated with the genetic distance between the parents. It is concluded that, holding all other factors affecting response to selection constant, concerns about the magnitude of heritability at low‐yielding locations are not justified and should not prevent them from being used as selection sites.

Mapping adaptation of barley to droughted environments

“…One of the encouraging findings in the present study is the detection of significant genetic variation for yield in the eight severely stressed environments where the mean yield was less than 2 t/ha. This is similar to a previous report of a lack of correlation between broad sense heritability and mean yield where heritabilities exceeding 50% were observed in environments yielding less than 1 t/ha (Al Yassin et al 2005). Moreover, we were also able to detect between two and five significant QTLs in environments with mean yields less than 2 t/ha and one of the most consistent genomic regions that we detected in the whole study was located in bin 7 on chromosome 7H, where four out of the five significant associations came from the four Jordanian sites with mean yield ranging from 0.3 to 1.2 t/ha.…”

Genetic Dissection of Heat Stress Tolerance in Soybean through Genome-Wide Association Studies and the Use of Genomic Prediction to Enhance Breeding Applications

“…We noted seven accessions had initiated flowering (R1 growth stage) within three weeks of plants, which is dramatically different from the normal expectation of planting to R1 duration of about 6-8 weeks. Generally, heritability was lower under heat stress, a trend also observed in other crops under marginal conditions (Al-Yassin et al, 2005; Kumar et al, 2007; Longmei et al, 2021).…”

Genetic parameters and morpho-agronomic characterization of barley in the Brazilian Savannah

“…Broad sense heritability, which can vary within the same species, was not found here, showing the value of preliminary selection in the representative environment for commercial production. In contrast, values between 0 and 93% were reported for barley in environments where climate and soil factor varied considerably (27,29).…”