Estimates of Heritability and Genetic Correlation for Five Traits in Female Hop Accessions

Abstract

Little has been published on the heritability of traits in hop (Humulus lupulus). What has been published does not provide adequate information for the determination of selection protocol. This article is the first to report narrow sense heritabilities and genetic correlations for economic traits in female hop plants. Seven female and 14 male accessions were crossed using a North Carolina Mating Design I. At least two offspring per cross were analyzed in three replicates for the determination of genetic parameters. Data were collected on yield, α-acids, β-acids, hop storage index (HSI), and essential oil content. Significant differences (P ≤ 0.05) among maternal families were observed for all five traits. USDA female accessions 56013 (1,985.28 kg/ha) and 56009 (2117.28 kg/ha) produced offspring with highest average yield. Maternal lines 21055 and 21254 produced families with the highest average α-acids content, while 65009 produced offspring with the highest average content of β-acids. Maternal families derived from 21522, 56013, and 65009 all had more desirable HSI values than did the other families. Finally, 21055, 62013, and 65009 produced offspring possessing the highest average content of essential oils of the maternal lines. Narrow sense heritability values were highest for α-acids (h2 = 0.88 ± 0.17), moderate for β-acids content (h2 = 0.35 ± 0.02) and HSI (h2 = 0.31 ± 6.1 × 10–6), and low for essential oil content (h2 = 0.12 ± 5.3 × 10–4). Heritability value for yield was more difficult to ascertain significance due to the high standard error associated with the estimate (h2 = 0.20 ± 1,463). Significant negative genetic correlations were estimated between α-acids and β-acids (r = – 0.42), α-acids and yield (r = −0.66), HSI and yield (r = −0.63), and essential oil content and yield (r = −0.38). Significant positive genetic correlations observed were for β-acids with yield (r = 0.84), HSI with α-acids (r = 0.28), and essential oil content and α-acids (r = 0.43). The information obtained from this research should enable hop breeders to make informed decisions regarding breeding protocol for these five economic traits.