Open Access

ARTICLE

Foliar Application of Brassinolide Induced Regulation of Grain Yield and Quality, Antioxidant Responses and Aroma in Fragrant Rice

Jinhai Liu^1,2,3,#, Rifang Lai^1,2,3,#, Longxin He^1,2,3, Pipeng Xing^1,2,3, Haowen Luo^1,2,3, Shuying Yang⁴, Yingbin Zou⁴, Xiangru Tang^1,2,3,*

1 State Key Laboratory for Conservation and Utilization of Subtropical Agricultural Bioresources, South China Agricultural University, Guangzhou, 510642, China
2 Scientific Observing and Experimental Station of Crop Cultivation in South China, Ministry of Agriculture, Guangzhou, 510642, China
3 Guangzhou Key Laboratory for Science and Technology of Aromatic Rice, Guangzhou, 510642, China
4 College of Agronomy, Hunan Agricultural University, Changsha, 410128, China

* Corresponding Author: Xiangru Tang. Email:
# These authors contributed equally to the work

Phyton-International Journal of Experimental Botany 2022, 91(5), 1061-1071. https://doi.org/10.32604/phyton.2022.017634

Received 26 May 2021; Accepted 09 October 2021; Issue published 24 January 2022

Abstract

Brassinolide (BR) is a new green plant growth regulator. The present field study was conducted on two fragrant rice cultivars (i.e., Meixiangzhan-2 and Xiangyaxiangzhan) to study the effects of foliar application of BR on fragrant rice performance. At the heading stage, BR solutions at 0.05, 0.15, 0.25 and 0.50 mg L-1 were sprayed on fragrant rice at 600 liters per hectare; these treatments were named as BR1, BR2, BR3 and BR4, respectively. The treatment sprayed with distilled water was taken as a control (CK). Compared with CK, the BR2 treatment significantly enhanced the chlorophyll concentration and net photosynthetic rate for Meixiangzhan-2, and Xiangyaxiangzhan. The BR3 and BR4 treatments increased the concentrations of chlorophyll a, chlorophyll b and carotenoid, and also enhanced net photosynthetic rate by 31.91% and 40.43%, respectively. Higher grain yields were recorded in the BR2 treatment than on CK on Meixiangzhan-2, while on Xiangyaxiangzhan, the BR3 and BR4 treatments increased grain yield compared with CK. In relation to CK, higher head rice rates were recorded in the BR2 treatment for Meixiangzhan-2, and in the BR3 and BR4 treatments for Xiangyaxiangzhan. BR treatments (BR2 for Meixiangzhan-2, BR3 and BR4 for Xiangyaxiangzhan) also significantly enhanced the activities of GPX, SOD and CAT by 10.22% to 23.00%, and reduced the malonaldehyde concentration. In addition, we observed that some BR treatments (BR2 for Meixiangzhan-2, BR3 and BR4 for Xiangyaxiangzhan) decreased the grain 2-acetyl-1-pyrroline concentration of fragrant rice.

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