Inheritance of entire and lobed leaf in Cynara cardunculus L

Abstract

In globe artichoke (Cynara cadunculus var. scolymus), the presence of entire leaf type in adult plants is a characteristic of the early Catanesi group, as 'Violet de Provence' and 'Blanca de Tudela', among others. Both of these attributes (i.e., entire leaf and precocity) failed to be transmitted by sexual means. In the cultivated cardoon (Cynara cadunculus var. altilis) some materials also present uniformely entire mature leaves, with a weak intensity of lobing and absence of secondary lobes. In this case, the attribute is seed maintained. In the present contribution we studied the inheritance of entire leaf type in a cross of a globe artichoke genetic stock ('Cada 33- 49-25') of deeply lobed leaves and a local landrace of cultivated cardoon ('Schiavoni'), possessing uniform entire leaves. All the observations were conducted in field adult plants about four months after transplantation. The F1 ('Schiavoni' × 'Cada 33-49-25') plants were of the lobed leaf type. The F2 showed 183 lobed leaf and 69 entire leaf type plants. This segregation fitted a 3:1 ratio (χ2=0.76; p=0.38). The backcross towards the entire leaf parent presented 51 lobed and 42 entire leaf plants, adjusting a 1:1 ratio (χ2=0.87; p=0.35). We concluded that entire leaf is governed by a single recessive allele that could be designated (el). In adition, as the entire leaf type is only found in the early cultivars of globe artichoke, we studied the days to anthesis of the first capitulum in the F2 population, in a way to see if there was also a relation in our material between entire leaf and precocity. The F2 was randomly divided in nine groups of about 20 plants. The date of first capitulum anthesis was recorded in each plant, and avararaged in each of the nine groups according to leaf type (entire and lobed). No significant differences were found in the number of days to reach flowering of the first capitulum between plants bearing entire and lobed leaves (F=2.77; p<0.13; df=1, n=9). Thus, in our segrergating population, the association between entire leaf and precocious flowering did not hold.