Effect of fungal endophytes of rice variety Ld 368 on growth and brown spot disease incidence of rice

Abstract

Use of chemicals for growth enhancement and disease control in plants has resulted in hazardous influences to the environment and human health. Therefore, less harmful methods should be implemented and the possibility of using microbes for this purpose has been investigated. Endophytic fungal assemblages have been known to enhance plant growth and decrease disease incidence in some crops including rice and thus can be used as an alternative to chemicals. Therefore, this study was aimed to isolate the endophytic fungal communities associated with the rice variety Ld 368 with a view to examine the possibility of using them for plant growth enhancement and management of brown spot disease incidence. Brown spot disease caused by Bipolaris oryzae is one of the major rice diseases prevalent in Sri Lanka. Healthy plant parts of variety Ld 368 were used for the isolation of endophytes. 31 endophytic fungal species were isolated, and eight of the most frequently isolated fungal species were tested for their ability to inhibit the growth of B. oryzae using dual culture assays. From the fungal species tested, Trichoderma sp.1, Trichoderma sp.2 and Chaetomium sp. inhibited the colony growth of Bipolaris Oryzae significantly (P ≤ 0.05) under in-vitro conditions. Based on the results of in-vitro tests, spore suspensions of the more effective endophytes were inoculated separately to healthy Ld 368 seedlings to evaluate their efficacy in controlling brown spot disease and to determine their effect on rice plant growth under greenhouse conditions. Two inoculation methods (i.e. seedling and soil inoculation) were used to identify the best approach to introduce the endophytic fungi into the plants. Plants inoculated with Trichoderma sp.1 and Chaetomium sp. using seedling inoculation method showed the lowest disease incidence as well as a significant difference (P ≤ 0.05) in shoot length and fresh and dry weight of plants. These results indicated that the tested endophytic fungal sp. have the ability to control brown spot disease incidence and enhance plant growth of rice variety Ld 368.

Mangrove endophytic fungi: Biocontrol potential against Rhizoctonia solani and biofertilizers for fragrant rice cultivation

“…Rice ( Oryza sativa L.) is a widely cultivated crop which serves as the staple dietary for more than half of the world's population, particularly to Asians and Africans [ 1 ]. However, it is prone to both biotic and abiotic stresses whose combined effect can reduce the average crop yield by more than 50 % [ [2] , [3] , [4] , [5] ].…”

Hongos patógenos del grano/semilla de arroz (<i>Oryza sativa</i>) asociados al manchado: Alternativas sustentables de control

“…Los hongos endófitos como Chaetomium globosum mejoran el crecimiento de las plantas y reducen la incidencia de enfermedades. En Priyadarshani et al (2018) se probó el efecto de endófitos de hongos aislados con mayor frecuencia en planta de arroz. Las plantas inoculadas con dichos endófitos mostraron un aumento significativo en la altura de la planta, el peso fresco y el peso seco en comparación con las plantas no inoculadas después de 4 semanas, tiempo que podría deberse a la tasa de colonización de los hongos endófitos.…”

“…estudios. EnAbdel-Fattah et al (2007) las plántulas de arroz tratadas con Trichoderma harzianum mostraron un porcentaje de incidencia de la mancha marrón entre un 46,9% y un 53,5% Priyadarshani et al (2018). observaron incidencias mucho más bajas de la enfermedad, con valores del 5% y 15% con plántulas de arroz tratadas con Trichoderma spp.…”

“…ensayadas mostraron distintos grados de antagonismo con cada uno de los patógenos cuando fueron enfrentados en cultivos duales. Se registran antecedentes similares de este hongo frente a patógenos de arroz(Abdel-Fataah et al 2007; Hassan et al 2017; Khalili et al2012;Priyadarshani et al 2018). Las cepas de Trichoderma harzianum utilizadas en este estudio, fueron usadas previamente enMoya et al (2020) frente a Pyrenophora teres en cebada donde mostraron una capacidad inhibitoria en un rango de 18% a 54% en comparación con el control, resultados superiores a los reportados en este estudio.…”

“…Las cepas de Trichoderma harzianum utilizadas en este estudio, fueron usadas previamente enMoya et al (2020) frente a Pyrenophora teres en cebada donde mostraron una capacidad inhibitoria en un rango de 18% a 54% en comparación con el control, resultados superiores a los reportados en este estudio. EnPriyadarshani et al (2018) reportaron valores de inhibición micelial entre un 47% a un 64,4% para Trichoderma spp. y 29,5% para Chaetomium spp.…”