Assessment of artichoke hybrids under USA and Italian conditions and the hereditability of some important traits

Abstract

Globe artichoke (Cynara cardunculus L. subsp. scolymus) hybrids are not Mendelian F1 with the consequent uniformity postulated by Mendel. This is due to the fact that hybrids are not originated from crosses between two pure lines; in fact, globe artichoke suffers strong inbreeding depression. Hence, the hybrid uniformity is one of the most important characteristics together with their improved characteristics for quality and morphological traits. To select hybrids lines, to be introduced for fresh consumption and industry processes, some uniform lines with promising characteristics have been selected in California in spring 2014 and evaluated in two contrasting environments such as the California desert of Brawley (33°02'48”N; 115°31'43”W) in spring 2014 and the Italian Mediterranean environmental conditions of Ladispoli (Rome) (41°57'29N; 12°07'10E) in spring 2015. The same procedures have been also adopted in the following year. The characteristics distribution among the evaluated hybrids has been studied utilizing multivariate and regression analyses. Hybrids have been also characterized by molecular markers to assess their genetic distance and parents' effects. Hybrids, on the base of their morphological traits, could be divided into 3 or 4 clusters the most important traits to discriminate the hybrids in all the years are earliness, spiny, distance between main head and first shoot, head shape, receptacle shape, bracts density, bract shape, and bract color. Hereditability values, of some important traits such as: earliness, plant height, presence of spines, presence of mucron, colour, head shape, and head compactness, have been estimated in globe artichoke. The differences between maternal and paternal hereditability are also reported and discussed.