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van Wesemael, J.

Publications and source records attributed to van Wesemael, J..

2 recordsLinked to original sources

Unlocking the power of gene banks: diversity in base growth temperature provides opportunities for climate-smart agriculture

Implementation of context-specific solutions, including cultivation of varieties adapted to current and future climatic conditions, were found to be effective in establishing resilient, climate-smart agricultural systems. Gene banks play a pivotal role in this. However, a large fraction of the collections remains neither genotyped nor phenotyped. Hypothesising that significant genotypic diversity in Musa temperature responses exists, this study aimed to assess the diversity in the worlds largest banana gene bank in terms of base temperature (Tbase) and to evaluate its impact on plant performance in the East African highlands during a projected climate scenario. 116 gene bank accessions were evaluated in the BananaTainer, a tailor-made high throughput phenotyping installation. Plant growth was quantified in response to temperature and genotype-specific Tbase were modelled. Growth response of two genotypes was validated under greenhouse conditions, and gas exchange capacity measurements were made. The model revealed genotype-specific Tbase, with 30 % of the accessions showing a Tbase below the reference of 14 {degrees}C. The Mutika/Lujugira subgroup, endemic to the East African highlands, appeared to display a low Tbase, although within subgroup diversity was revealed. Greenhouse validation further showed low T sensitivity/tolerance to be related to the photosynthetic capacity. This study, therefore, significantly advances the debate of within species diversity in temperature growth responses, while at the same time unlocking the power of gene banks. Moreover, we provide a high throughput method to reveal the existing genotypic diversity in temperature responses, paving the way for future research to establish climate-smart varieties.

physiology↗

The impact of stomatal kinetics on diurnal photosynthesis and water use efficiency under fluctuating light

Dynamic light conditions require continuous adjustments of stomatal aperture. As stomatal conductance (gs) kinetics are a magnitude slower than photosynthesis (A), they are hypothesized to be key to plant productivity and water use efficiency. Using step-changes in light intensity, we studied the diversity of light-induced gs kinetics in relation to stomatal anatomy in five banana genotypes (Musa spp.) and modelled the impact on A and intrinsic water use efficiency (iWUE). Banana generally exhibited a strong limitation of A by gs, indicating a priority for water saving. Significant genotypic differences in gs kinetics and gs-based limitations of A were observed. For two contrasting genotypes the impact of differential gs kinetics on A and iWUE was further investigated under realistic diurnally fluctuating light conditions and at whole-plant level. Genotype-specific stomatal kinetics observed at the leaf level were corroborated at whole-plant level, suggesting that despite differences in gs control at different locations in the leaf and across leaves, genotype-specific responses are still maintained. However, under diurnally fluctuating light conditions gs speediness had only a momentary impact on the diurnal iWUE and carbon gain. During the afternoon there was a setback in kinetics: the absolute gs and the gs responses to light were damped, strongly limiting A and the diurnal iWUE. We conclude that the impact of the differential gs kinetics on the limitation of A was dependent on the target light intensity, the magnitude of change, the gs prior to the intensity change and particularly the time of the day. One sentence summaryGenotype-specific stomatal rapidity is for the first time validated at whole-plant level, but under fluctuating light the impact of stomatal dynamics depends on other factors like the time of the day.

plant biology↗