Diversity of Leaf Cuticular Transpiration and Growth Traits in Field-Grown Wheat and Aegilops Genetic Resources

Kristína Gašparovič,Pavol Hauptvogel,Marián Brestič,Marek Živčák

doi:10.3390/agronomy11030522

Kristína Gašparovič, Pavol Hauptvogel + Show 2 more

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https://doi.org/10.3390/agronomy11030522

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Abstract

Plants are subjected to unregulated water loss from their surface by cuticular transpiration. Therefore, specific morphophysiological changes may occur during leaf development to eliminate water loss. This study aimed to examine the cuticular transpiration of 23 winter wheat genotypes and their wild-growing predecessors of the genus Aegilops, which were divided into three groups to demonstrate their diversity. The genotypes were sown in autumn and grown in regular field trials at the Research Institute of Plant Production in Piešťany, Slovakia. Cuticular transpiration and growth parameters were analyzed in the postanthesis growth stage. Gravimetric measurement of residual water loss was performed on detached leaves with a precisely measured leaf area. The lowest nonproductive transpiration values were observed in modern wheat genotypes, while higher cuticular transpiration was observed in a group of landraces. Aegilops species generally showed the highest cuticular transpiration with increased water loss, but the total water loss per plot was low due to the low leaf area of the wild wheat relatives. Some of the growth parameters showed a good correlation with cuticular transpiration (e.g., dry mass per plant), but direct relationships between leaf traits and cuticular transpiration were not observed. This study identified a high diversity in cuticular resistance to water loss in wheat and Aegilops accessions of different origins. The potential of identifying and exploiting genetic resources with favorable cuticular transpiration in crop breeding is discussed.

Highlights

The plant cuticle plays a crucial role in the survival of terrestrial plants [1,2]
Differences among the genotypes were highly significant for all traits (p < 0.05); the specific results of the analysis of variance (ANOVA) are not displayed here, and we focused mainly on the comparisons of individual genotypes and groups of genotypes
The lowest cuticular transpiration was observed in the group of modern wheat genotypes (Biscay, Piopio-4, and Mottin), in which we found almost 50% lower cuticular transpiration compared to the average value found in all genotypes (11.70 to 12.93 g m2 h−1 )

Summary

Introduction

The plant cuticle plays a crucial role in the survival of terrestrial plants [1,2]. Representing a dynamic and selective barrier between the plant and the atmosphere, it delays the onset of cellular dehydration stress under drought and is considered an essential component of protection from drought [3,4,5,6]. The extent of cuticular transpiration of the water in the plant and water acquisition from the soil significantly impacts plant fitness and survival [8,9]. Ultrastructure, and chemical composition can vary dramatically in a species-, organ- and tissue-specific manner [2,11]. As they develop their leaves, plants can resort to specific morphological alterations to regulate their water losses, such as changes in the palisade parenchyma thickness [12] or the epidermis and cuticle water tightness [13], the latter being essential to control water losses, especially during drought periods, through cuticular transpiration [14,15]

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