Shade stress on maize seedlings biomass production and photosynthetic traits

Liuzheng Yuan,Zhiyong Cai,Huiqiang Wang,Shidie Zhu,Hui Zhang,Yundong Zhang,Tianqi Li,Lu Zhang,Jiafeng Fu,Jiayou Liu,Manman Yuan,Weihua Wu,Hongtao Zhang,Haixia Yan

doi:10.1590/0103-8478cr20201022

Liuzheng Yuan, Zhiyong Cai + Show 12 more

Open Access

https://doi.org/10.1590/0103-8478cr20201022

Copy DOI

Journal: Ciência Rural	Publication Date: Jan 1, 2022
Citations: 5	License type: CC BY 4.0

Affiliation: Luohe Academy of Agricultural Sciences

Abstract

ABSTRACT: The responses of two maize (Zea mays L.) cultivars, ‘LY336’ (shade tolerant) and ‘LC803’ (shade sensitive), to shade stress in a pot experiment conducted in the 2015 and 2016 growing seasons were investigated. The impact of 50% shade stress treatment on shoot biomass, photosynthetic parameters, chlorophyll fluorescence, and malondialdehyde (MDA) content was evaluated. The shoot biomass of the two maize hybrids was decreased significantly by shade stress treatment, for shade stress 7 d, the LC803 and LY336 were reduced by 56.7% and 44.4% compared with natural light. Chlorophyll fluorescence parameters of LY336 were not significantly affected by shade stress, whereas those of LC803 were significantly affected, the Fo increased under shade stress; however Fm, FV/FM and ΦPSII were decreased under shade stress. Among photosynthetic parameters measured, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate were significantly decreased compared with natural light, LY336 and LC803 reduction by 28.0%, 22.2%, 57.7% and 35.5%, 18.9%, 62.4%; however, intercellular CO2 concentration (Ci) was significantly increased, for the two cultivars. Under shade stress for different durations (1, 3, 5, 7 d), Pn, Gs, Ci, and MDA content differed significantly between the two cultivars. Results indicated that different maize genotypes showed different responses to shading. Shade-tolerant genotypes are only weakly affected by shade stress.

Highlights

Maize (Zea mays L.) is the third most important crop worldwide after wheat and rice (WATTO et al, 2011)
Under shading for 7 d, the shoot biomass of Lianchuang 803’ (LC803) was reduced by 56.7% and that of LY336 was reduced by 44.4% compared with the biomass produced under natural light
Chlorophyll fluorescence Analysis of chlorophyll a fluorescence parameters revealed that the Fo of LY336 increased non-significantly by 3.9% in the shading treatment, whereas the Fo of LC803 increased significantly by 32.1% in the shading treatment (P < 0.05), compared with that under natural light (Table 2)

Summary

Introduction

Maize (Zea mays L.) is the third most important crop worldwide after wheat and rice (WATTO et al, 2011). Shading of maize at different developmental stages decreases grain yield, and affects the normal development of other agronomically important traits, such as reduction in internode length (FOURNIER & ANDRIEU, 2000), reduced Dry matter accumulation (GAO et al, 2017), delays in flowering and silking time (CUI et al, 2014; STRUIK, 1983; WANG et al, 2020), decrease in kernel set in the apical ear region or varying degrees of barrenness (CUI et al, 2014), inhibition of silk elongation (FOURNIER & ANDRIEU, 2000; WANG et al, 2020), increase or decrease in plant height, delay in appearance of new leaves (STRUIK, 1983), and reduction in leaf thickness (WARD & WOOLHOUSE, 2006). Yuan et al identified a number of major quantitative trait loci (YUAN et al, 2012), protein regulatory networks(GAO et al, 2020) and microRNAs (YUAN et al, 2016) that regulate the mechanism of shade tolerance

Objectives

Methods

Results

Conclusion