Effect of Shading on Interspecific Competition Between Aegilops tauschii and Triticum aestivum

Abstract

Aegilops tauschii is a competitive invasive weed typically found in winter wheat fields. In this study, using the replacement series experiments designed by de Wit, the effects of different shading treatments on the morphological structure, physiological characteristics, and competitiveness of the invasive plant A. tauschii were comparatively analyzed with the aim of providing knowledge for the ecological control of this weed in wheat fields. The results showed that in terms of morphological characteristics, shading caused an increase in plant height, leaf area, and specific leaf area (SLA); and a decrease in the root-to-crown ratio (R/C) of both A. tauschii and wheat plants. With regard to physiological characteristics, both A. tauschii and wheat plants adapted to the low-light environment by increasing the chlorophyll content, with an increase of chlorophyll b in particular. It could be concluded from the changes in superoxide dismutase (SOD) activity and thiobarbituric acid reactive substances (TBARS) content that the low-intensity shading treatment significantly improved the stress resistance of A. tauschii , thus ensuring the continuation of its normal photosynthesis. In addition, the plasticity index average value of eight morphological indicators of A. tauschii (e.g., plant height and leaf area) was 0.18, which was greater than that of wheat (0.17). Similarly, the plasticity index average value of four physiological indicators of A. tauschii (e.g., chlorophyll content and SOD activity) was 0.46, which was also higher than that of wheat (0.37). Finally, the competitive balance (CB) value of A. tauschii showed that its competitiveness under low light conditions was still greater than wheat, but gradually diminished with increasing shading rate. In short, A. tauschii displays a certain adaptability to low light environments, but shading treatment may also significantly reduce its competitive inhibition of wheat.

Effects of soil drought on competitiveness of the invasive weed Aegilops tauschii

“…studied the invasive plant Urochloa arrecta and also suggested that the success of invasive grass plants occurs due to their drought resistance rather than their high competitiveness. However, according to the ndings in this study, regarding the effects of ooding(Wang et al 2021), shading(Wang et al 2022), and salt-alkali stress (Wang and Chen 2023) on the competitiveness of A. tauschii and its soil feedback, the successful invasion of A. tauschii is not only related to its outstanding adaptability but also may be related to its high competitiveness.…”

Effect of saline–alkaline stresses on the interspecific competition between Aegilops tauschii and Triticum aestivum

“…A. tauschii plants not only have strong reproduction ability, easy transmission and wide suitable range; but also display emergence times, growth habits very similar to wheat. This weed fiercely competes with wheat for resources such as fertilizer, water and light, resulting in a reduction in wheat production (Wang et al 2022). As one of the world's most important food crops, wheat has been frequently affected by salt stress.…”