Soil drought occurrence during dry season has been the main constraint, besides prolonged flooding during rainy season, in increasing cropping intensity and rice productivity in tropical riparian wetland. Use of droug...Soil drought occurrence during dry season has been the main constraint, besides prolonged flooding during rainy season, in increasing cropping intensity and rice productivity in tropical riparian wetland. Use of drought tolerant rice genotype might be a suitable option for overcoming such problem. This study focused on the effects of gradual soil drying during early vegetative growth stage on morphological and physiological traits of five Oryza glaberrima genotypes, namely RAM12, RAM14, RAM59, RAM97 and RAM101, and two Oryza sativa subsp japonica genotypes, i.e. Koshihikari and Minamihatamochi. The plants were subjected to 6 d of gradual soil drying condition from 15 days after transplanting(DAT) to 20 DAT, and were allowed to recover until 22 DAT. Gradual soil drying reduced plant growth as indicated by dry mass accumulation. Drought reduced stomatal conductance and increased leaf rolling score of all the genotypes. All the genotypes showed comparable response on stomatal conductance, but O. glaberrima genotypes performed higher in leaf rolling recovery. Meanwhile, O. sativa genotypes decreased total leaf area and specific leaf area, but increased specific leaf weight in order to avoid further damages due to drought stress. Drought tolerance mechanisms in RAM101, RAM12, RAM59 and RAM14 were associated with leaf morpho-physiological responses, root traits and dry biomass accumulation.展开更多
Wilt disease with unknown etiology causes mass mortality in commercial Acacia mangium nurseries in South Sumatra.This pathogen induces symptoms of chlorosis in the lower leaves and develops into the shoots;subsequentl...Wilt disease with unknown etiology causes mass mortality in commercial Acacia mangium nurseries in South Sumatra.This pathogen induces symptoms of chlorosis in the lower leaves and develops into the shoots;subsequently,the plants wither and die.This research identifies the path-ogenic species causing this wilt disease and to assess its pathogenicity or virulence.Fifteen isolates of Fusarium oxysporum with varying colony sizes and color pigments were recovered from symptomatic A.mangium seedlings.The pathogenicity test showed that all isolates could infect plants with wilt severity reaching 80%,and the pathogen was verified as causing vascular disease.Koch’s postulate was verified by re-isolating the F.oxysporum isolates.The pathogen was confirmed by observing the morphological characters and elongation factor 1-α(tef1-α)gene sequences as F.oxysporum.展开更多
基金funded by the Program of the United Graduate School of Agricultural Sciences, Kagoshima Universitysupported by Program Penelitian Unggulan Profesi Universitas Sriwijaya (Grant No. 0006/UN9/SK.LP2M.PT/2018)+1 种基金Program PMDSU (Grant No. 093/SP2H/LT/DRPM/IV/2018)Enhancing International Publication Program by Directorate of Higher Education of the Ministry of Research, Technology and Higher Education of the Republic of Indonesia
文摘Soil drought occurrence during dry season has been the main constraint, besides prolonged flooding during rainy season, in increasing cropping intensity and rice productivity in tropical riparian wetland. Use of drought tolerant rice genotype might be a suitable option for overcoming such problem. This study focused on the effects of gradual soil drying during early vegetative growth stage on morphological and physiological traits of five Oryza glaberrima genotypes, namely RAM12, RAM14, RAM59, RAM97 and RAM101, and two Oryza sativa subsp japonica genotypes, i.e. Koshihikari and Minamihatamochi. The plants were subjected to 6 d of gradual soil drying condition from 15 days after transplanting(DAT) to 20 DAT, and were allowed to recover until 22 DAT. Gradual soil drying reduced plant growth as indicated by dry mass accumulation. Drought reduced stomatal conductance and increased leaf rolling score of all the genotypes. All the genotypes showed comparable response on stomatal conductance, but O. glaberrima genotypes performed higher in leaf rolling recovery. Meanwhile, O. sativa genotypes decreased total leaf area and specific leaf area, but increased specific leaf weight in order to avoid further damages due to drought stress. Drought tolerance mechanisms in RAM101, RAM12, RAM59 and RAM14 were associated with leaf morpho-physiological responses, root traits and dry biomass accumulation.
基金The work was supported by the Directorate General of Research and Development,Ministry of Research,Technology and Higher Education through the PMDSU scholarship 2020−2021 according to the Director of Research and Community Service,Directorate of Research and Community Service,chaired by Ahmad Muslim number 0124/UN9/SB3.LP2M.PT/2020.
文摘Wilt disease with unknown etiology causes mass mortality in commercial Acacia mangium nurseries in South Sumatra.This pathogen induces symptoms of chlorosis in the lower leaves and develops into the shoots;subsequently,the plants wither and die.This research identifies the path-ogenic species causing this wilt disease and to assess its pathogenicity or virulence.Fifteen isolates of Fusarium oxysporum with varying colony sizes and color pigments were recovered from symptomatic A.mangium seedlings.The pathogenicity test showed that all isolates could infect plants with wilt severity reaching 80%,and the pathogen was verified as causing vascular disease.Koch’s postulate was verified by re-isolating the F.oxysporum isolates.The pathogen was confirmed by observing the morphological characters and elongation factor 1-α(tef1-α)gene sequences as F.oxysporum.
