De novo domestication of wild tomato using genome editing

Breeding of crops over millennia for yield and productivity1 has led to reduced genetic diversity. As a result, beneficial traits of wild species, such as disease resistance and stress tolerance, have been lost2. We devised a CRISPR–Cas9 genome engineering strategy to combine agronomically desirable traits with useful traits present in wild lines. We report that editing of six loci that are important for yield and productivity in present-day tomato crop lines enabled de novo domestication of wild Solanum pimpinellifolium. Engineered S. pimpinellifolium morphology was altered, together with the size, number and nutritional value of the fruits. Compared with the wild parent, our engineered lines have a threefold increase in fruit size and a tenfold increase in fruit number. Notably, fruit lycopene accumulation is improved by 500% compared with the widely cultivated S. lycopersicum. Our results pave the way for molecular breeding programs to exploit the genetic diversity present in wild plants

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

[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.This research was financed by the Spanish Ministry of Science and Innovation (MICINN) (project AGL2005-08083-C03-01). The authors thank Dr. Luis Mejia and the Universidad de San Carlos of Guatemala for providing the CPD4777 accession, among others. The authors thank Professor Jun Zhu, director of the Bioinformatics Institute, Zhejiang University, China, for his comments and for kindly providing the software used in the data analyses.Adalid Martinez, AM.; Rosello Ripolles, S.; Valcárcel Germes, M.; Nuez Viñals, F. (2011). Analysis of genetic control of â-carotene and L-ascorbic acid accumulation from a wild cherry orange-brownish tomato accession. Euphytica. 184(2):251-263. doi:10.1007/s10681-011-0584-xS251263184