Quantifying the expression of potato genetic diversity in the high Andes through growth analysis and modeling

Crop growth analysis and modeling based on a slightly modified version of the LINTUL model was used for the assessment of the effect of genetic diversity, as expressed by differences in characteristics such as ploidy, parentage and other specific traits, on the growth and yield responses of Andean potatoes to agroecological conditions in Bolivia. The aim of the present study was to conduct a comparative growth analysis of nine genotypes to describe their performance under the prevalent conditions in the high Andes. We also simulated the performance of nine genotypes from the species Solanum tuberosum subspecies andigenum and tuberosum, Solanumajanhuiri, and their hybrids as affected by frost. The simulations were run using a user-friendly simulation model based on the LINTUL framework.Three native genotypes: Ajanhuiri (S. ajanhuiri), Gendarme and Waycha (S. tuberosum ssp. andigenum); one introduced genotype: Alpha (S. tuberosum ssp. tuberosum); and five hybrids (Condori, Tunari, Sajama, Illimani, and Totoreña) provided the crop data required as inputs to the model, from field experiments conducted over four years under favorable management conditions. Each experimental location also provided daily weather data required by the model. Genotypic differences, ascribed to parentage and ploidy, were evidenced by differences in growth response observed under a range of simulated frost scenarios. The diploid ajanhuiri showed better canopy cover and yield than most tetraploids. However, the average yield of the tetraploids was reduced by including the long day Alpha genotype (tuberosum), which did not perform as well as the others. Nevertheless, Alpha showed higher harvest index than the average of the short day genotypes and hybrids. Andigenum genotypes showed 12% higher yields than the andigenum hybrids. Gendarme showed the best growth parameters overall followed by Waycha. The adapted LINTUL model was validated as it adequately (R2 > 0.88) reproduced observed field responses in the calibration experiments. This correspondence between the simulations and the experimental results demonstrated the adequacy of the model, which explained more than 82% of the variations in growth parameters. All statistical metrics used to test the validity of the model to simulate potato yield and yield components in the high Andes showed the model's robustness.