Evaluation of apricot fruit quality diversity in two countries, France and New Zealand

International audience

English. New Zealand and French stone fruit industries desire new long-storing, sweettasting apricot cultivars. The climacteric nature of apricots (a high ethylene production that stimulates softening via cell wall degradation) shortens their storage life. Breeders in France (FR) and New Zealand (NZ) have some apricot populations producing fruit with unusually low climacteric behavior and with a large range of total soluble solids (TSS). Trials in FR and NZ shared the same research protocols, for optimal comparison and verification. Up to 60 genotypes representative of fruit diversity in each country were studied in June-July 2016 in FR and January-February 2017 in NZ, with four cultivars in common. For each genotype, six fruits, selected according to firmness, were characterized for fruit quality traits on the day of harvest. Measurements were intact fruit: compression firmness, near infrared spectroscopy (NIRS), ethylene production, skin color, and penetrometer; and fruit tissue samples: TSS, titratable acidity (TA), andindividual sugar and organic acid contents. A large diversity was observed for firmness, from 4 to 55 N in NZ and 1 to 36 N in FR. Ethylene production ranged from 0 to 740 nmol h-1 kg-1 in NZ and 0 to 4257 nmol h-1 kg-1 in FR, and discriminated between known lowand high-ethylene cultivars. Conversely, the variability was larger in NZ than in FR for biochemical content: TSS ranged from 8 to 24 °Brix in NZ and 10 to 22 °Brix in FR and TA from 85 to 514 meq kg-1 in NZ and 24 to 350 meq kg-1 in FR. NIRS has the ability to discriminate across countries. The fruit genetic variability opens new opportunities for breeding programs.