GENETIC ANALYSIS OF AGRONOMIC AND CHEMICAL CHARACTERS IN HOP (HUMULUS LUPULUS L.)
Genetic parameters of several important economic characters were estimated from a broad-based hop (Humulus lupulus L.) population created from genetic material derived from Europe and North America. This randomly chosen population was considered to represent a broad cross-section of germplasm available in New Zealand. Twenty seedlings from each of 40 maternal half sib families were grown in a randomised complete block design with four replications of five seedlings per plot. Measurements were made on each of the seedlings for three growing seasons. In total, 8 characters were measured on female seedlings, and three were measured on male seedling plants in the population. Estimates of genetic variances for each character and genetic correlations between the various characters were calculated for each season separately. The entire data set was then analysed over the three seasons to estimate the importance of genotype x year interactions for each of the measured characters. Narrow sense heritabilities for both family and individual seedling selection schemes were then calculated for each character. The 40 maternal parents, which were in a nearby germplasm collection, were also measured for four characters over five seasons. Heritability estimates for these four characters were determined by the regressions analysis of parent on offspring. For the two most important characters, yield and alpha acids, the heritability estimates for half sib families was considered to be high, while estimates for single plants showed that heritability for yield was low and high for alpha acids. For most characters, there was a significant family x year interaction component of variance but this was much smaller than that of the variance component for families. The expected genetic advance for each character for three different recurrent selection schemes was calculated. In general, phenotypic recurrent selection was considered to be a better option than half sib family recurrent selection schemes. There was a positive genetic correlation between yield and alpha acids in the study. The implications of using this broad-based population for selection are discussed.
Beatson, R.A. (2005). GENETIC ANALYSIS OF AGRONOMIC AND CHEMICAL CHARACTERS IN HOP (HUMULUS LUPULUS L.). Acta Hortic. 668, 53-58
plant breeding, quantitative genetics, genotype x environment interaction, heritability, recurrent selection