Effects of exogenous auxin on yield in foxtail millet ( Setaria italica L.) when applied at the grain-filling stage
Foxtail millet ( L.) is of high nutritious value, which is an important crop in arid and semi-arid regions. The objective of this experiment was to explore the effects of the synthetic auxin naphthalene acetic acid (NAA) on the physiological processes of foxtail millet, and to provide a theoretical...
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Published in | Frontiers in plant science Vol. 13; p. 1019152 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
Frontiers Media S.A
04.01.2023
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Subjects | |
Online Access | Get full text |
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Summary: | Foxtail millet (
L.) is of high nutritious value, which is an important crop in arid and semi-arid regions. The objective of this experiment was to explore the effects of the synthetic auxin naphthalene acetic acid (NAA) on the physiological processes of foxtail millet, and to provide a theoretical basis and technical approaches for its efficient use in millet cultivation. Two foxtail millet varieties ('Jingu 21' and 'Zhangzagu 5') were treated with six concentrations of NAA from 0-144 mg L
at the grain-filling stage in field experiments. The photosynthetic pigment contents, gas exchange parameters, chlorophyll fluorescence parameters, and grain yield were measured in foxtail millet. The results showed that low concentrations of NAA (18-36 mg L
) increased the contents of photosynthetic pigments, and increased the activities of antioxidant enzymes, the photosynthetic rate, and the activity of photosystem system II (PS II). At higher NAA concentrations, the facilitation effect of the treatments diminished, showing a clear concentration effect. In this study, yield was significantly and positively correlated with PS II effective quantum yield (Y(II)) and the PSII electron transport rate (ETR), and the net photosynthetic rate (Pn) was significantly and positively correlated with chlorophyll content, stomatal conductance (Gs), Y(II), and ETR. These results also indicated that exogenous NAA application promotes the production of ATP and NADPH by increasing the efficiency of electron transfer within the photosystems and also improved photochemical utilization, which facilitates the fixation and reduction of carbon, ultimately leading to an increase in Pn and increasing grain yield in foxtail millet. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Reviewed by: Panfeng Guan, Zhengzhou University, China; Faisal Zulfiqar, The Islamia University of Bahawalpur, Pakistan; Ran Han, Shandong Academy of Agricultural Sciences, China Edited by: Shuaifeng Geng, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, China These authors have contributed equally to this work This article was submitted to Crop and Product Physiology, a section of the journal Frontiers in Plant Science |
ISSN: | 1664-462X 1664-462X |
DOI: | 10.3389/fpls.2022.1019152 |