Effect of Gibberellic Acid on Growing-Point Development of Non-Vernalized Wheat Plants under Long-Day Conditions.

Milan Skalicky,Vaclav Hejnak,Jan Kubes,Jaroslava Martinkova,Pavla Vachova,Shokoofeh Hajihashemi

doi:10.3390/plants9121735

Milan Skalicky, Vaclav Hejnak + Show 4 more

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https://doi.org/10.3390/plants9121735

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Abstract

The goal of this study was to determine whether the application of gibberellic acid (GA3) to seeds of common wheat varieties with different vernalization and photoperiod requirements affects the transition from vegetative to generative stage. Three varieties of wheat with different photoperiod sensitivities and vernalization were selected for the experiment—the winter varieties, Mironovskaya and Bezostaya, and the spring variety, Sirael. Seeds were treated with different concentrations of GA3 and plants were grown under long-day conditions with monitoring of their photosynthetic activity (Fv/Fm, Pn, E, gs). We monitored the activity of the photosynthetic apparatus by checking the plants to see if they were growing properly. The phenological stages of the wheat species were checked for indications of a transition from the vegetative to the generative stage. Selected concentrations of GA3 had no effect on the compensation of the vernalization process (transition to the generative phase). Chlorophyll fluorescence was one of the factors for monitoring stress. The variety, Bezostaya, is similar to the spring variety, Sirael, in its trends and values. The growth conditions of Bezostaya and Sirael were not affected by the activity of the photosynthetic apparatus. The development of growing points in winter varieties occurred at the prolonged single ridge stage. The spring variety reached the stage of head emergence after sixty days of growth (changes to the flowering phase did not appear in winter wheat). Application of GA3 to the seeds had no effect on the transition of the growing point to the double-ridge generative stage. The present study highlights the priming effect of GA3 on seeds of common wheat varieties with different vernalization and photoperiod requirements as it affected the transition from vegetative to generative stage.

Highlights

In wheat (Triticum aestivum L.), flowering is regulated genetically but is influenced by environmental factors such as photoperiod and temperature [1]
The double-ridge stage is considered the moment of transition of the growing point from the vegetative to generative stage of development [47,48,49]
The results of our experiments revealed that after 60 days, the growing points in the winter wheats, Mironovskaya and Bezostaya (Figure 4), were at the single-ridge stage at all GA3 concentrations; the transition into the generative stage did not take place

Summary

Introduction

In wheat (Triticum aestivum L.), flowering is regulated genetically but is influenced by environmental factors such as photoperiod and temperature [1]. The adaptability of wheat to a wide range of environments is favored by allelic diversity in genes regulating growth habit (VRN) and photoperiod response (PPD) [2,3]. Wheat is primarily a long-day (LD) plant that requires a photoperiod of fourteen hours or more [4]. The major environmental signal modulating flowering time is the photoperiod, the variation in day length during the growing season [5]. Natural variations in photoperiod response are mainly determined by allelic differences in the PPD1 gene [3,6] and the photoperiod requirement may differ at different stages of development.

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