Open Access

ARTICLE

Effects of Paclobutrazol Seed Priming on Seedlings Quality, Physiological and Bakanae Disease Index Characteristics of Rice (Oryza sativa L.)

by Hossam S. El-Beltagi^1,2,*, Mohamed Fathi El-Nady³, Adel A. Rezk^1,4, Abdelaziz M. Tahoon⁵, Mohammed I. Al-Daej¹, Dina Abdulmajid⁶, Mohamed M. El-Mogy⁷, Elsayed Abd Elmaksoud Abomarzoka⁸, Sherif Mohamed El-Ganainy^7,9, Metwaly Mahfouz Salem Metwaly³

1 Agricultural Biotechnology Department, College of Agriculture and Food Sciences, King Faisal University, Al-Ahsa, 31982, Saudi Arabia
2 Biochemistry Department, Faculty of Agriculture, Cairo University, Gamma St, Giza, 12613, Egypt
3 Department of Agricultural Botany, Faculty of Agriculture, Kafrelsheikh University, Kafr El-sheikh, 33516, Egypt
4 Plant Virology Department, Plant Pathology Research Institute, Agriculture Research Center, Giza, 12619, Egypt
5 Rice pathology Department, Plant Pathology Research Institute, Agricultural Research Center (ARC), Kafr El-Sheikh, 33717, Egypt
6 Rice Research and Training Centre, Field Crops Research Institute, Agricultural Research Centre, Kafr El-Sheikh, 33717, Egypt
7 Department of Arid Land Agriculture, College of Agriculture and Food Sciences, King Faisal University, Al-Ahsa, 31982, Saudi Arabia
8 Crop Physiology Research Department, Field Crops Research Institute, Agricultural Research Center, Kafr El-Sheikh, 33717, Egypt
9 Plant Pathology Research Institute, Agricultural Research Centre (ARC), Giza, 12619, Egypt

* Corresponding Author: Hossam S. El-Beltagi. Email:

(This article belongs to the Special Issue: Influence of Biotic and Abiotic Stresses Signals on Plants and their Performance at Different Environments)

Phyton-International Journal of Experimental Botany 2024, 93(10), 2535-2556. https://doi.org/10.32604/phyton.2024.056734

Received 29 July 2024; Accepted 10 October 2024; Issue published 30 October 2024

Abstract

Rice (Oryza sativa L.) is one of the most important cereal crops in the world. Bakanae disease is a significant rice disease widely distributed in rice-growing regions worldwide. Therefore, the present investigation aimed to assess the optimal concentrations of paclobutrazol (PBZ) as a treatment for rice grains (cv. Sakha 108) to control bakanae disease, also evaluating its impact on grain germination, seedling growth parameters as well as disease index. Paclobutrazol concentrations had no significant impact on seed germination, regardless of whether the seeds were incubated with Fusarium fujikuroi or not. Application of PBZ, either alone or in combination with fungal pathogens, negatively impacted the rice seedlings’ height. Paclobutrazol at 25, 50 and 100 mg/L, combined with the fungal pathogen positively impacted root length. Paclobutrazol at 3 and 6 mg/L mitigated the adverse impact on chlorophyll pigments content in infected seedlings. The highest proline contents were achieved by 100 mg/L PBZ alone or in combination with fungal pathogens. It has been observed that the application of PBZ, either alone or in combination with a fungal pathogen, leads to the enhancement of catalase, peroxidase, and polyphenol oxidase activities. The median lethal concentration of PBZ was 0.874 mg/L; applying low concentrations of paclobutrazol effectively increased the percentage of fungal growth suppression. Application of PBZ, at higher concentrations (50 and 100 mg/L), decreased infection percentage and disease severity index (DSI) significantly. These findings suggest that PBZ can be an effective treatment for controlling bakanae disease and enhancing resistance in rice plants.

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