Influence of foliar application of silicon on chlorophyll fluorescence, photosynthetic pigments, and growth in water-stressed wheat cultivars differing in drought tolerance

Abstract

The influence of foliar application of silicon (Si) on chlorophyll contents, chlorophyll fluorescence, and growth of four wheat cultivars differing in drought tolerance (Sirvan and Chamran, as relatively drought tolerant, and Shiraz and Marvdasht, as drought sensitive) was examined under water deficit (100% and 40% F.C.) created in a greenhouse. The results showed that water deficit decreased shoot and root lengths, shoot dry weight, root dry weight, water utilization efficiency, chlorophyll a and b, and chlorophyll stability index. In contrast, foliar application of Si improved plant growth parameters and chlorophyll pigment concentration under water deficit; however, it did not significantly affect wheat growth under control conditions. Limited water supply reduced the values of minimal fluorescence from dark-adapted leaf (F 0 ), maximal fluorescence from dark-adapted leaf (F m ), maximum quantum yield of PSII (F v /F m ), effective quantum yield of PSII (ΦPSII), photochemical quenching (q P ), and apparent photosynthetic electron transport rate (ETR). However, under water deficit, foliar application of Si application increased the earlier mentioned parameters. In contrast, nonphotochemical quenching (q N ) and F 0 /F m increased under water deficit, and application of Si further improved these parameters. Chlorophyll fluorescence analysis suggested that Si alleviated water deficit-induced adverse effects by reducing nonphotochemical quenching, while increasing F v /F m and q P , so that it improved the light use efficiency in the four wheat cultivars under stress. Overall, we concluded that drought-sensitive cultivars (Shiraz and Marvdasht) could resemble resistant cultivars upon foliar application of silicon.

Effect of Water Stress and some Anti - Transpirants on Growth, Yield and Quality of Okra Plants (Abelmoschus esculentus)

“…Data in Table 6 show that the highest significant values of chlorophylls a, b, total chlorophyll and chlorophyll a/b ratio of okra leaves were recorded at 10 days intervals during both seasons compared with irrigation intervals at 20 days which had the lowest significant values of the studied parameters. Similar results were obtained by Maghsoudi et al (2015).…”

Role of silicon under water deficit stress in wheat: (Biochemical perspective): A review

“…The foliar application of silicon resulted in beneficial effect on chlorophyll fluorescence and photosynthetic pigments, thereby suggesting an enhanced drought tolerance in wheat plants (Maghsoudi et al, 2015). Amongst the various methods (seed priming, fertigation and foliar spray) of applying Si, foliar spray was more effective in alleviating the adverse effects of drought.…”

“…Most of the work is done with soil application of silicon; however relatively little work has been carried out with respect to foliar treatment which has gained momentum recently e.g. Bukhari et al (2015) and Maghsoudi et al (2015) in wheat; Sayed and Gadallah, (2014) in maize; Pilon et al (2014) and (2013) in potato; Passala et al (2014) in Beneficial role of silicon: Beneficial effects of Si are usually obvious in crops which actively accumulate Si in their shoots. This is because most of the beneficial effects of Si are expressed through Si deposited on the leaves and stems.…”

Respuesta fisiológica diurna del tomate a la aplicación de silicio bajo condiciones de salinidad

“…Valores altos de Fo significan daños en el centro de reacción del PSII o una reducción de la capacidad para transferir la energía de excitación de la antena hacia el centro de reacción (Baker, 2008;Khan et al, 2016). Datos contradictorios son los reportados por Maghsoudi et al (2015) quienes estudiaron la Fo sobre la aplicación de Si en trigo sometido a estrés hídrico. Ellos explican que el estrés provocado por la falta de agua disminuyó los valores de Fo.…”