PROPOSED BREEDING STRATEGY FOR YIELD IMPROVEMENT OF HEXAPLOID TRITICALE (X TRITICOSECALE WITTMACK) .1. GENETIC-VARIABILITY AND PHENOTYPIC STABILITY

An experiment to partition the components of variation in selected lin es of triticale was conducted at Lincoln, Canterbury, New Zealand. Gen etic variation, genotype x environment interaction, and phenotypic sta bility of 20 quantitative characters, as well as biochemical variation were studied in 11 hexaploid triticale lines. For the quantitative st udy, the lines were grown in four environments. The randomised complet e block design was used in each environment. Data were collected on an individual plant basis except for five characters, measured on a plot basis. The results showed that genetic variation for most of the char acters was high as expressed by the high broad sense heritability (>50 %). Biochemical variation showed major differences between lines, thou gh each line, except 'Till' and 'Salvo', was relatively homogenous. Ge notype x environment interaction was strong for 16 characters. Lines s uch as 'Lasko', 'Salvo', 'Presto', 'Juanillo', 'Aranui', and 'Swans' h ave great potential for triticale yield improvements as they had avera ge stability and were well adapted to all environments. Of the early m aturing lines-'Fulls', 'Juanillo', 'Swans', and 'Till' are likely to b e the best for incorporation in the breeding programme as they had ave rage stability and could be harvested earlier than other lines.