Confounding Factors in Container-Based Drought Tolerance Assessments in Solanum tuberosum

Abstract

Potato is an important food crop with high water-use-efficiency but low drought tolerance. The bottleneck in drought tolerance breeding is phenotyping in managed field environments. Fundamental research on drought tolerance is predominantly done in container-based test systems in controlled environments. However, the portability of results from these systems to performance under field conditions is debated. Thus, we analyzed the effects of climate conditions, container size, starting material, and substrate on yield and drought tolerance assessment of potato genotypes compared to field trials. A leave one out assessment indicated a minimum of three field trials for stable tolerance prediction. The tolerance ranking was highly reproducible under controlled-conditions, but weakly correlated with field performance. Changing to variable climate conditions, increasing container size, and substituting cuttings by seed tubers did not improve the correlation. Substituting horticultural substrate by sandy soil resulted in yield and tuber size distributions similar to those under field conditions. However, as the effect of the treatment × genotype × substrate interaction on yield was low, drought tolerance indices that depend on relative yields can be assessed on horticultural substrate also. Realistic estimates of tuber yield and tuber size distribution, however, require the use of soil-based substrates.

LIDAR-Based Phenotyping for Drought Response and Drought Tolerance in Potato

“…The comparison of the DRYMp distribution showed large differences between lines and considerable variation between years. The differences between years may result from insufficient sample size for tolerance assessment in a single experiment (Köhl et al 2021). Based on the data from experiments F3 to F8 (see Table S1), Köhl et al (2021) showed that a minimum of three experiments is required to achieve a stable tolerance assessment.…”

“…The differences between years may result from insufficient sample size for tolerance assessment in a single experiment (Köhl et al 2021). Based on the data from experiments F3 to F8 (see Table S1), Köhl et al (2021) showed that a minimum of three experiments is required to achieve a stable tolerance assessment. Therefore, we calculated a general DRYMp for each genotype for the three test environments from the combined data of the three (big-bag, pot) or seven (field) experiments; the distribution of which are shown in Fig.…”

“…During the experiment, plants grew in big-bags with a substrate volume similar to the soil volume per plant in the field trials. Drought stress was imposed by increasing the time interval between subsequent irrigations, thus mimicking the situation in the field, where drought stress arises from infrequent water supply by rain (Köhl et al 2021).…”

Cultivation Using Coir Substrate and P or K Enriched Fertilizer Provides Higher Resistance to Drought in Ecologically Diverse Quercus Species

“…We acknowledge that plant response in a semi-controlled environment does not necessarily translate to the performance of open-field performance of planted seedlings under drought [ 129 , 130 ], since in other studies, lower growth and photosynthesis rates have been found in potted plants, without changes in biomass ratios among plant parts as compared to open-field transplants [ 131 ]. Thus, our results should be confirmed with field trials where roots have an entire soil profile to develop.…”

Expression analysis of candidate genes as indicators for commencing drought stress in starch potatoes

“…First, in the present study, plants were derived from in vitro cultivation without storage starch from a seed tuber. Because the size of the seed tubers influences the performance of the plants, the comparability of plants from in vitro culture is limited (Köhl et al, 2021). Furthermore, the substrate is an essential factor for drought stress trials (Köhl et al, 2021).…”