Soil Water Content Directly Affects Bud Burst Rate in Single-Node Cuttings of Perennial Plants

Santiago Signorelli,Juwita R Dewi,Michael J Considine

doi:10.3390/agronomy12020360

Santiago Signorelli, Juwita R Dewi + Show 1 more

Open Access

https://doi.org/10.3390/agronomy12020360

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Abstract

The use of single-node cuttings of shoots as explants to study bud dormancy and its physiology under controlled conditions is a common practice in grapevine (Vitis vinifera L.) or other perennial plant research. In particular, this method has been extensively used to understand the effect of different chemicals on bud dormancy and bud burst. However, the soil water content in those experiments is usually not reported and its relevance is often neglected. Here, we observed that an unevenly distributed soil water content in a tray containing multiple explants results in an uneven pattern of bud burst within the same treatment. Thus, we hypothesised that soil water content can dramatically affect bud burst. To investigate this, we first established that fresh single-node cuttings were able to transport water into the buds. We then tested the rate of bud burst at different water treatments (35%, 55%, 70%, 85%, and 100% of field capacity; FC). We observed a clear dependence of bud burst on water, in which, at very low levels of water, bud burst does not occur; after 35% FC, bud burst rate increases with water content until around 85% FC; and, from 85% FC, bud burst rate becomes independent of water content. These data highlight the critical importance of monitoring soil water content in any bud burst assay in perennials. Finally, we provide a detailed protocol for determining and controlling field capacity and other soil water content indicators.

Highlights

The use of explants of perennial plants is a common practice to evaluate kinetics of bud burst, for instance, to evaluate the depth of dormancy, the effect of environmental clues, or applied chemicals on bud burst [1,2,3,4]
The use of explants enables the use of controlled conditions, which is a major limitation when working with perennial plants, as well as removing the influence of dominance influences of the corpus and competing sinks
Agronomy 2022, 12,r3e6p0resentation of the tray showing the bending of the seedling tray and the water flux generated towards the centre

Summary

Introduction

The use of explants of perennial plants is a common practice to evaluate kinetics of bud burst, for instance, to evaluate the depth of dormancy, the effect of environmental clues, or applied chemicals on bud burst [1,2,3,4]. Despite the wide use of this methodology, the influence of water availability on bud burst has not been reported. This is important because the application of chemicals usually implies adding water to the single-node cuttings, as water is the most common solvent used. The water content of soil in single-node cuttings experiments is commonly not reported. We hypothesise that soil water content can explain much of the stochastic variability observed in bud burst experiments and, that determining a fixed water content within the experiments is critical to underpin the validity and reproducibility of data reported

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