Analysis of genetic control of â-carotene and L-ascorbic acid accumulation from a wild cherry orange-brownish tomato accession

Abstract

[EN] An additive-dominance, additive 9 additive (ADAA) and genotype 9 environment interaction mix model was used to study the genetic control of beta-carotene and L-ascorbic acid in six basic generations (P-1, P-2, F-1, F-2, BC1P1 and BC1P2) of tomato derived from the cross CDP8779 accession (Solanum lycopersicum L.) x CDP4777 accession (S. lycopersicum var. cerasiforme). The study was performed in two environments: (1) open field; (2) protected environment, consisting of hydroponic cultivation in a glasshouse. The results indicate that beta-carotene accumulation was mainly additive (32.2% of the genetic component), with a small dominant component (4.2%) and an important additive x environment interaction contribution (63.6%). In target environments with moderate to high temperatures and no limiting radiation, this the expression additive x environment interaction could substantially enhance the beta-carotene content. This trait showed also a high narrow-sense heritability (h(2) = 0.62). Ascorbic acid accumulation was also mainly additive (61.7% of the genetic component), with a minor additive epistatic component (21.5%). This epistatic effect caused a negative heterosis that reduced the positive main additive effect. Nevertheless, in the described target environments, the additive 9 environment interaction contribution (16.8%) may enhance the ascorbic acid content and compensate for the negative heterosis effect. The total narrow-sense heritability of this trait can be considered useful (h(2) = 0.52). In conclusion, the CDP4777 accession is a very interesting donor parent for the joint improvement of beta-carotene (without diminishing lycopene content) and ascorbic acid content in commercial nutraceutical tomato breeding programmes; the F-1 hybrids derived from this accession showed nearly 450% of the commonly reported average beta-carotene content and close to 130% of the ascorbic acid content of the female parent.