NEW APRICOT GERMPLASM SELECTED BY TEN CHARACTERISTICS

Some of the main problems in apricot growing in temperate climate are caused by the relatively short dormant period of this species, low hardiness of generative buds, early blooming, relatively short harvest season, and insufficient fruit quality of some of the existing cultivars. A breeding program was developed at the Apricot Research Station, Silistra, Bulgaria with the main objective to significantly enrich the genetic diversity in Prunus armeniaca, as well as to increase the efficacy of the selection process by estimating breeding value of the main cultivars when used as parents in controlled crosses or in open pollination. Over 3600 seedlings were obtained from 72 intraspecific crosses and from 58 open pollinated cultivars. Approximately 1300 hybrids, reached the adult phase were studied in detail by ten important biological and pomological characteristics during 1989-1999. Twenty-nine elites, which completed their dormancy period after the control cultivar ‘Hungarian Best’, were selected. Thirteen highly cold-resistant seedlings and 75 elites with first bloom of 3 to 9 days in average after the control were also selected. Over two hundred seedlings were selected for their season of ripening—from 19 days before to 56 days after the standard cultivar. Five of them were categorized as very early ripening, 65 early, 119 late, 14 very late, and 2 were extremely late ripening. The average productivity of 46 elites exceeded this of the standard cultivar by 3 to 5 times. We selected 16 hybrids with large and 3 with very large fruit. Thirty-nine seedlings, bearing fruit with over 50% blush, and 42 elites with excellent fruit taste were selected. After a complete evaluation by all ten characteristics, the best nine elites, which combine greatest number of valuable traits expressed at the highest level, were selected and recommended for cooperative trial plantings and further commercial development.

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