Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an ...Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an eco-friendly and economical option.In the current study,F_(3) progenies derived from a cross of susceptible parent PMS-18-B(PAU 10845-1-1-1-1)×resistant parent RP Path 77(RP patho-17)were used to identify potential QTLs linked to BS resistance and to associate this resistance with a temporal spike in defense-related enzymes.展开更多
A field study was undertaken to ascertain the effects of elicitors viz. benzothiadiazole （BTH） and salicylic acid （SA） on defense related enzymes viz. peroxidase, phenylalanine ammonia lyase, superoxide dismutase,...A field study was undertaken to ascertain the effects of elicitors viz. benzothiadiazole （BTH） and salicylic acid （SA） on defense related enzymes viz. peroxidase, phenylalanine ammonia lyase, superoxide dismutase, chitinase and 13-1,3-glucanase, and phenols in rice （Pusa Basmati I） plants. First foliar spray of BTH （50 mg/kg） and SA （50 mg/kg） was done at the maximum tillering stage and inoculation with Rhizoctonia solani was carried 24 h after elicitor treatment. Elicitors were further sprayed at every growth stage. Time course analysis showed peak accumulation of defense related enzymes and phenols in the rice leaves treated with BTH and SA, and accumulation was the highest at the flowering stage. Higher enzymatic activity was observed in elicitor treated plants inoculated with R. solani. Compared to the untreated control plants, application of elicitors before R. solani inoculation significantly elicited the defense related enzymes and phenols. Moreover, application of elicitors had a positive effect on yield and disease reduction. It is suggested that pretreatment of rice leaves with BTH and SA could be used to enhance the level of protection against sheath blight and to improve rice yield in the fields.展开更多
Brown rot or bacterial wilt of potato caused by Ralstonia solanacearum, is an economically important disease. Potato, cv. Nicola, was found to be relatively highly resistant to the infection with R. solanacearum and s...Brown rot or bacterial wilt of potato caused by Ralstonia solanacearum, is an economically important disease. Potato, cv. Nicola, was found to be relatively highly resistant to the infection with R. solanacearum and showed 15.12% wilt disease index, meantime, cv. Kara showed intermediate resistance with 37.40% disease index while, cv. Spunta was susceptible and showed 80.33% disease index. The role of defense-related enzymes in imparting resistance in potato against R. solanacearum was investigated by quantifying enzymes activity and gene expression of three defense- related enzymes, peroxidase, polyphenol oxidase and catalase. Peroxidase showed maximum activity 0.488 min<sup>-1</sup>·g<sup>-1</sup> early at 12 h after pathogen inoculation in the cv. Nicola, whereas in susceptible cultivar Spunta showed lower activity of maximum 0.226 min<sup>-1</sup>·g<sup>-1</sup> later at 48 h after inoculation. While, the moderately resistant cultivar Kara showed intermediate activity for the peak and its time. Meanwhile, polyphenol oxidase showed similar trends to that of peroxidase. On the contrary, catalase showed the highest activity values in the susceptible, cv. Spunta, while, in relatively highly resistant (cv. Nicola) and the moderately resistant (cv. Kara) showed lower values of activity and up to 96 h after inoculation. Meanwhile, gene expression of related enzymes the RT-PCR was used. At zero time, the relatively highly resistant potato cultivar, Nicola, showed the highest values of gene expression for both Peroxidase (POD) and Poly Phenol Oxidase (PPO). While, the susceptible potato cultivar, Spunta showed the lowest values. On the contrary, Catalase (CAT) gene expression was the highest in the susceptible, cv. Spunta, and was the lowest in the relatively highly resistant, cv. Nicola, while, was of intermediate values in the intermediate resistance, cv. Kara. Results show that peroxidase and polyphenol oxidase activities can be used as biochemical markers to reveal the resistance and susceptibility nature of potato cultivars against bacterial wilt disease of potato caused by R. solanacaerum.展开更多
基金supported by Punjab Agricultural University,Ludhiana,India,for providing the infrastructure and other facilities for conducting experiments.All other forms of support and financial assistance are duly acknowledged.
文摘Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an eco-friendly and economical option.In the current study,F_(3) progenies derived from a cross of susceptible parent PMS-18-B(PAU 10845-1-1-1-1)×resistant parent RP Path 77(RP patho-17)were used to identify potential QTLs linked to BS resistance and to associate this resistance with a temporal spike in defense-related enzymes.
基金supported by the University Grants Commission Rajiv Gandhi National Fellowship(RGNF) of India
文摘A field study was undertaken to ascertain the effects of elicitors viz. benzothiadiazole （BTH） and salicylic acid （SA） on defense related enzymes viz. peroxidase, phenylalanine ammonia lyase, superoxide dismutase, chitinase and 13-1,3-glucanase, and phenols in rice （Pusa Basmati I） plants. First foliar spray of BTH （50 mg/kg） and SA （50 mg/kg） was done at the maximum tillering stage and inoculation with Rhizoctonia solani was carried 24 h after elicitor treatment. Elicitors were further sprayed at every growth stage. Time course analysis showed peak accumulation of defense related enzymes and phenols in the rice leaves treated with BTH and SA, and accumulation was the highest at the flowering stage. Higher enzymatic activity was observed in elicitor treated plants inoculated with R. solani. Compared to the untreated control plants, application of elicitors before R. solani inoculation significantly elicited the defense related enzymes and phenols. Moreover, application of elicitors had a positive effect on yield and disease reduction. It is suggested that pretreatment of rice leaves with BTH and SA could be used to enhance the level of protection against sheath blight and to improve rice yield in the fields.
文摘Brown rot or bacterial wilt of potato caused by Ralstonia solanacearum, is an economically important disease. Potato, cv. Nicola, was found to be relatively highly resistant to the infection with R. solanacearum and showed 15.12% wilt disease index, meantime, cv. Kara showed intermediate resistance with 37.40% disease index while, cv. Spunta was susceptible and showed 80.33% disease index. The role of defense-related enzymes in imparting resistance in potato against R. solanacearum was investigated by quantifying enzymes activity and gene expression of three defense- related enzymes, peroxidase, polyphenol oxidase and catalase. Peroxidase showed maximum activity 0.488 min<sup>-1</sup>·g<sup>-1</sup> early at 12 h after pathogen inoculation in the cv. Nicola, whereas in susceptible cultivar Spunta showed lower activity of maximum 0.226 min<sup>-1</sup>·g<sup>-1</sup> later at 48 h after inoculation. While, the moderately resistant cultivar Kara showed intermediate activity for the peak and its time. Meanwhile, polyphenol oxidase showed similar trends to that of peroxidase. On the contrary, catalase showed the highest activity values in the susceptible, cv. Spunta, while, in relatively highly resistant (cv. Nicola) and the moderately resistant (cv. Kara) showed lower values of activity and up to 96 h after inoculation. Meanwhile, gene expression of related enzymes the RT-PCR was used. At zero time, the relatively highly resistant potato cultivar, Nicola, showed the highest values of gene expression for both Peroxidase (POD) and Poly Phenol Oxidase (PPO). While, the susceptible potato cultivar, Spunta showed the lowest values. On the contrary, Catalase (CAT) gene expression was the highest in the susceptible, cv. Spunta, and was the lowest in the relatively highly resistant, cv. Nicola, while, was of intermediate values in the intermediate resistance, cv. Kara. Results show that peroxidase and polyphenol oxidase activities can be used as biochemical markers to reveal the resistance and susceptibility nature of potato cultivars against bacterial wilt disease of potato caused by R. solanacaerum.
