Development of a recurrent apple breeding programme in New Zealand: a synthesis of results, and a proposed revised breeding strategy

Abstract

This paper describes an apple breeding population that has been developed in New Zealand since 1990 to broaden the genetic base for cultivar breeding. The population is now in its third generation, with recurrent selection for general combining ability being the underlying approach. During the 20 years of the programme, nearly 1,000 trees have been progeny tested. An early focus on selection within open-pollinated tests has been replaced by selection within control-pollinated tests. Genetic evaluation methods along with estimates of genetic parameters (e.g. heritability, genetic correlations, and genotype-by-environment interactions), genetic gain, and genetic diversity are summarised in this paper. The third-generation crossing programme involving nearly 350 parents is almost completed and seedlings from these crosses are in the nursery. In the revised breeding strategy, three hierarchal populations are envisioned to better integrate this broad-based population with the more commercially focused cultivar breeding programme: main breeding population (MBP), elite breeding populations (EBP) and cultivar development populations (CDP). A two-subline structure and a minimum of two crosses per parent will be implemented in the MBP. EBP will focus on developing parents for breeding goals of the CDP. Forward-selected (based on estimated breeding values) candidates from the main-and elite populations will be used as parents of the CDP. Cloning of seedlings in elite populations and also in the firststage of cultivar development, will be investigated as a tool for enhancing predictability and shortening the cycle for delivering genetic gain.

Precocity and a long-term cropping in apple progenies grown on M 9 rootstock

“…Otherwise, our results concerning the start of fruiting are in agreement with data published by Visser (1964Visser ( , 1967. Our results concerning the mean level of yields within the studied progenies are more or less in agreement with currently published data (Kellerhals, Meyer 1994;Brown, Maloney 2009;Kumar et al 2010;Durand et all, 2013).…”

“…A range of large apple breeding programmes are presently being conducted in many countries of the world focused also on the aim to obtain novelties with higher and regular fruit-bearing (Sansavini et al 2005;Brown, Maloney 2009Kumar et al 2010;Tóth et al 2012).…”

Cryopreservation of winter-dormant apple buds: establishment of a duplicate collection of Malus germplasm

“…), one of the most economically important cultivated fruit crops, has been subjected to heavy selection and breeding programs. Historically, apple breeders worked with a narrow genetic base involving crosses among popular commercial cultivars (Kumar et al 2009), but the introduction of traits from wild species has a long history, too. Greater genetic diversity in apple breeding is needed to develop innovative cultivars with resistance to various diseases, good fruit quality, high productivity, and increased health benefits, as well as reduced growing and handling costs.…”

Genetic diversity and apple leaf spot disease resistance characterization assessed by SSR markers

“…However, a limited number of Malus species has been used up to present for breeding disease resistance, except few breeding programs, like Purdue Rutgers, Illinois, USA, and some European apple breeding programs (Korban and Tartarini 2009). The majority of the parents used in breeding programs have explored a strait gene pool, involving crosses among widespread commercial cultivars (Kumar et al 2010). For instance, the varieties Red Delicious, Golden Delicious and Jonathan, have been frequently utilized on apple breeding, producing several of the current cultivars (Noiton and Alspach 1996).…”