The New Zealand pear breeding project

The HortResearch pear breeding project commenced in 1983 with the aim of producing a new range of pear cultivars suitable for exporting from New Zealand to markets in Europe, Asia and North America. The project originally had four parts, Japanese, Chinese, European, and Inter-specific pear breeding. Now our breeding lines are more complex with most crosses including genetic backgrounds of more than one species as we believe that the largest genetic gains in fruit quality we are making are coming from our interspecific crosses. Annually about 3000 seedlings are produced and planted in the selection orchard. Seedlings are screened in the field for low susceptibility to pear scab, powdery mildew, and fireblight. Once the seedlings are fruiting, selection is made on fruit characteristics. We make directional selection for juicy flesh, lack of grit cells, high sweetness, high aroma, smooth bright skin finish, and large fruit size. Selection for fruit shape, sourness, texture, and colour is non-directional. Generation periods as low as 5 years have been achieved, by which time more than 80% of the seedlings have fruited. About 2% of the seedlings are selected for further evaluation in regional sites on clonal rootstocks. At this stage orchard and postharvest performance is assessed in detail. While we are continuing to select for tradition style pears, a lot of interest is being expressed in the innovations in fruit texture, flavour, and skin colour that are observed in the inter-specific populations. Character combinations of interest include European pear aroma with crisp juicy texture, red colour, and extended shelf life. Two Inter-specific selections have received Plant Variety Rights, one European and one Japanese selection are proposed and four other interspecific selections are being assessed for their commercial potential.