Regional variation in performance of New Zealand × Spanish white clover (Trifolium repens L.) hybrids in New Zealand

Abstract

Performances were analysed for F₁ progenies derived from hybridisation of 12 Spanish white clover plants with 7 New Zealand plants. Progenies were grown at 4 locations in New Zealand and growth data analysed for different seasons. The F₁ progenies successfully combined cool-season growth of the Spanish parents with the warm-season growth of the New Zealand parents. Gains in cool-season growth were, however, usually larger and more consistent at Palmerston North than at the other three locations. Differences among progeny groups from individual parent plants were significant for both the New Zealand and Spanish sources in all seasons at all locations. Progeny performances interacted strongly with season and location. However, results suggested that selection for cool-season growth at Palmerston North should produce material with improved cool-season growth at all locations. Relative gains at Lincoln and Gore would be small wherever selection was carried out. Interactions among individual Spanish and New Zealand parent plants were generally absent or weak. Although the Spanish component contributed greatly to winter growth at Palmerston North, the New Zealand population nevertheless made a large contribution to the genetic variance among F₁ progenies. Therefore further selection for winter growth within the F₁ propulation should take account of both parents.