Level and transmission of genetic heterozygosity in apricot (Prunus armeniaca L.) explored using simple sequence repeat markers

In this study, 17 peach simple sequence repeat (SSR) sequences were used in the exploration of the genetic heterozygosity level of several apricot cultivars from Spain, France, Greece, and the USA, and 23 descendants. The genotypes can be classified in three groups as a function of their genetic heterozygosity ( 1) local cultivars from Murcia ( Spain) ('Gitanos' and 'Pepito del Rubio') and several descendants from crosses among these cultivars, with very low genetic heterozygosities ( less than 0.30); ( 2) cultivars from France and Spain ('Moniqui', 'Currot' and 'Bergeron') and several descendants, with intermediate levels of genetic heterozygosity ( around 0.45); and ( 3) cultivars 'Orange Red' and 'Goldrich' from North America and 'Lito' from Greece, with the remaining descendants, having genetic heterozygosities higher than 0.50. The results showed the high increase of genetic heterozygosity in the case of descendants from complementary crosses. The use of cultivars from North America could increase greatly the genetic heterozygosity in the Spanish apricot breeding programs, enlarging the genetic variability of the local cultivars. On the other hand, in the case of transgressive crosses among local Spanish cultivars, the increase of genetic heterozygosity was much lower.