E.L. Cointry

Estimation of genetic parameters for yield traits in globe artichoke (Cynara scolymus L.).

Ten yield and phenological traits were evaluated in a population of 23 globe artichoke (Cynara scolymus L.) clones in order to estimate broad sense heritability, genetic coefficient of variation, expected selection gain and genetic correlations. The variation among clones was highly significant (p < 0.01) for all the characters, while the clone x year interaction was highly significant (p < 0.01) for days to first harvest (DH), harvest period (HP) and bottom height (BH). The interaction was also significant (p < 0.05) for the number of artichokes harvested (AN), height/diameter ratio (MR) and bottom diameter (BD). Heritability was intermediate to high: 0.83, 0.82, 0.94, and 0.48 for yield (YD), AN, MR and HP, respectively. The expected selection advance was related to the magnitude of the genetic coefficient of variation, and was over 30% of the mean for weight of secondary artichokes, bottom weight, harvest period and yield. Characters with highest association with yield were the number of artichokes and weight of secondary artichokes, W2, (rg= 0.98 and 0.99, respectively). Harvest period and days to harvest were negatively correlated (rg= -0.92**). DH was positively correlated with YD, W2, W1 and BW; while the opposite was true for HP; indicating that high yielding clones with good head size should be searched for in late maturing materials. Among the bottom quality characters, the high correlation between BW and W1 (rg= 0.94) would enable the consideration of the latter as an indicator of good industrial quality.

Diallel analysis for traits of economic importance in globe artichoke (Cynara scolymus)

Abstract A breeding strategy for globe artichoke (Cynara scolymus) is suggested after General and Specific Combining Ability between several clones were estimated to determine the gene action for yield‐related and morphological traits. Two sets of diallel crosses, without parents, using four selected clones in each were developed. A completely randomised design with three replications for each diallel cross was used. Significant differences between the mean values of several traits among both diallel sets were found. Most of the variables evaluated were primarily controlled by additive genetic effects. Therefore, simple recurrent selection would be effective for increasing the mean value of these variables.

Selección de progenitores en espárrago

The principal aim of this experiment was to ascertain what the variables are which best explain the variations among individuals within the populations of asparagus which originates from the cultivar Argenteuil and as a result select better plants to form new populations. The test, using 1,280 plants, was carried out at he experimental farm in the Facultad Ciencias Agrarias de la Universidad Nacional de Rosario, Santa Fe, Argentina, in 1996. During 1997 and 1998 the number of spears per plant (TU), the mean weight of spears (PM), mean diameter of spears (DI) total yield (RE), marketable yield (RM), days to first harvest (DAC), number of stalks (NUTA), plant height (ALT) and fresh weight of the fern (MASAV) were measured. According to an analysis of the principal components, the variables RE, RM, PM, DI and TU were responsible for 60% of the variation that exists within the population evaluated.