7 research outputs found
Data for "Ozone-tolerant rice for air-polluted environments"
No full textDescription of dataset
This dataset provides data from a project aimed at breeding of ozone tolerant rice lines. The lines were developed by introgressing previously reported ozone tolerance QTL (Frei et al. 2008) into the Bangladeshi elite rice varieties BINA dhan11 and BRRI dhan 28. The genetic markers and genotypes of the resulting lines are documented in the file ‘Sequence and Genotyping’. The different lines were then tested in a greenhouse experiment and field experiment (ozone concentrations, see file ‘Ozone data’). The remaining files present physiological and morphological data of the different breeding lines under control and high ozone conditions.
Abbreviations
- O3 = ozone
- ppm = parts per million
- ppb = parts per billion
- KASP = Kompetitive Allele-Specific PCR
- LBS = leaf bronzing score
- NDVI = normalized difference vegetation index
- Lic2 = Lichtenthaler index 2 (representing carotenoid/chlorophyll ratio)
- SC = stomatal conductance
- PhiPS2 = Quantum efficiency of photosystem 2 of light adapted leaves
- A = CO2 assimilation rate
- MDA = malondialdehyde
References
- Frei M, Tanaka JP, Wissuwa M (2008) Genotypic variation in tolerance to elevated ozone in rice: dissection of distinct genetic factors linked to tolerance mechanisms. Journal of Experimental Botany 59, 3741-3752.
- Alam MA, Islam MM, Do MK, Osimahon BO, Karki AK, Baburajan AI, Hartung M, Autarmat S, Feng Y, Wissuwa M, Frei M (2025) Ozone-tolerant rice for air-polluted environments. Global Change Biology, in press
Developing ozone-tolerant rice (Oryza sativa L.) through marker-assisted breeding for enhancing food security in air-polluted environments
No full textEnvironmental stressors, particularly tropospheric ozone (O₃), which significantly reduces crop yields, are increasingly threatening global food security. Rice (Oryza sativa L.), a staple food for more than half of the world’s population, is highly vulnerable to ozone stress. Chronic exposure to ozone results in reduced photosynthesis, accelerated senescence, and significant yield losses. This study aimed to develop ozone-tolerant rice varieties through marker-assisted breeding, focusing on two quantitative trait loci (QTLs), OzT8 and OzT9, known for conferring ozone tolerance.
The research was conducted in four phases. The first phase investigated the interactive effects of ozone stress and blast disease (Magnaporthe oryzae) on different rice genotypes under controlled greenhouse conditions. Physiological measurements—including spectral reflectance indices, gas exchange parameters, biochemical analysis, and yield data—revealed that ozone exposure reduced blast disease severity. However, blast infection did not significantly affect the sensitivity of rice to ozone. While breeding for ozone tolerance had long been hindered by concerns about potential trade-offs with disease resistance, this study provided confidence that breeding for both traits is feasible.
In the second phase, marker-assisted backcross breeding was employed to introgress OzT8 and OzT9 from the donor parent Kasalath into two ozone-sensitive Bangladeshi rice varieties, BRRI dhan28 and Binadhan-11. Successive generations of genotypic and phenotypic selection resulted in the development of breeding lines homozygous for the tolerant alleles. Subsequently, 77 breeding lines harboring OzT8 and/or OzT9 were evaluated in a greenhouse experiment. These lines were assessed for key physiological traits—such as stomatal conductance, chlorophyll fluorescence, nitrogen balance index—and agronomic traits, including grain yield and biomass accumulation. Several lines demonstrated enhanced ozone tolerance, improved photosynthetic efficiency, reduced lipid peroxidation, and superior yield performance compared to their parental lines.
In the third and fourth phases, comprehensive greenhouse and field trials were conducted to confirm the performance of the selected breeding lines. Physiological traits (e.g., nitrogen balance index, stomatal conductance, chlorophyll fluorescence) and agronomic traits (e.g., grain yield, harvest index) were thoroughly analyzed. Results validated the superior performance of breeding lines containing both OzT8 and OzT9, with several lines showing significant yield improvements under ozone stress conditions.
This study highlights the potential of marker-assisted breeding in developing ozone-tolerant rice varieties, offering a promising solution to mitigate ozone-induced yield losses and improve rice production in air-polluted regions. It concludes with a recommendation for multi-location trials to validate the stability of ozone tolerance across diverse environments and to explore the integration of additional QTLs for greater genetic diversity and broader adaptation.German Research Foundation (DFG
Interactive effects of tropospheric ozone and blast disease (Magnaporthe oryzae) on different rice genotypes
No full textRising tropospheric ozone concentrations can cause rice yield losses and necessitate the breeding of ozone-tolerant rice varieties. However, ozone tolerance should not compromise the resistance to important biotic stresses such as the rice blast disease. Therefore, we investigated the interactive effects of ozone and rice blast disease on nine different rice varieties in an experiment testing an ozone treatment, blast inoculation, and their interaction. Plants were exposed to an ozone concentration of 100 ppb for 7 h per day or ambient air throughout the growth period. Half of the plants were simultaneously infected with rice blast inoculum. Grain yield was significantly reduced in the blast treatment (17%) and ozone treatment (37%), while the combination of both stresses did not further decrease grain yields compared to ozone alone. Similar trends occurred for physiological traits such as vegetation indices, normalized difference vegetation index (NDVI), photochemical reflectance index (PRI), Lichtenthaler index 2 (Lic2), and anthocyanin reflectance index 1 (ARI1), as well as stomatal conductance and lipid peroxidation. Ozone exposure mitigated the formation of visible blast symptoms, while blast inoculation did not significantly affect visible ozone symptoms. Although different genotypes showed contrasting responses to the two types of stresses, no systematic pattern was observed regarding synergies or trade-offs under the two types of stresses. Therefore, we conclude that despite the similarities in physiological stress responses to ozone and blast, the tolerance to these stresses does not appear to be genetically linked in rice. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11356-022-19282-z
Association of faecal pH with childhood stunting: Results from a cross-sectional study
No full textBackgroundGut microbiota plays an important role in the growth of children. The gut of children with optimum growth is enriched in certain species, especially Bifidobacteria and Clostridia. Bifidobacteria and commensal Clostridia both contribute to formation of acidic stool, and an elevated faecal pH indicates reduction of these species in the gut. The purpose of the study was to investigate the association of faecal pH with childhood stunting.MethodsIn this cross-sectional study, 100 children with length-for-age Z score (LAZ) <−1 aged between 12 and 18 months were enrolled from the ongoing Bangladesh Environmental Enteric Dysfunction study conducted in Dhaka, Bangladesh. LAZ was measured by anthropometry and data on factors affecting linear growth were recorded. Faecal pH measurement was done using pH metre on freshly collected non-diarrhoeal faecal samples following standard procedure. Multiple quantile regression was done to quantify the relation between faecal pH and LAZ scores.ResultsThe mean LAZ and faecal pH of the children were −2.12±0.80 and 5.84±1.11, respectively. Pearson correlation analysis showed a statistically significant negative correlation between stool pH and the LAZ scores (p<0.01). After inclusion of other factors affecting linear growth into the regression model, a statistically significant inverse association was observed between faecal pH and LAZ score (p<0.01).ConclusionElevated faecal pH was found to have a significant association with stunted growth. As an indicator of gut microbiota status, faecal pH might have emerged as a possible indirect determinant of childhood stunting.Trial registration numberNCT02812615</jats:sec
