Resilience of rice (Oryza spp.) pollen germination and tube growth to temperature stress

Resilience of rice cropping systems to potential global climate change will partly depend on the temperature tolerance of pollen germination (PG) and tube growth (PTG). Pollen germination of high temperature-susceptible Oryza glaberrima Steud. (cv. CG14) and Oryza sativa L. ssp. indica (cv. IR64) and high temperature-tolerant O. sativa ssp. aus (cv. N22), was assessed on a 5.6–45.4 °C temperature gradient system. Mean maximum PG was 85% at 27 °C with 1488 µm PTG at 25 °C. The hypothesis that in each pollen grain, the minimum temperature requirements (Tn) and maximum temperature limits (Tx) for germination operate independently was accepted by comparing multiplicative and subtractive probability models. The maximum temperature limit for PG in 50% of grains (Tx(50)) was the lowest (29.8 °C) in IR64 compared with CG14 (34.3 °C) and N22 (35.6 °C). Standard deviation (sx) of Tx was also low in IR64 (2.3 °C) suggesting that the mechanism of IR64’s susceptibility to high temperatures may relate to PG. Optimum germination temperatures and thermal times for 1 mm PTG were not linked to tolerating high temperatures at anthesis. However, the parameters Tx(50) and sx in the germination model define new pragmatic criteria for successful and resilient PG, preferable to the more traditional cardinal (maximum and minimum) temperatures

Study to Find Hemodynamic Changes and Complications Occurring with Propofol and Etomidate During General Anaesthesia: A Tertiary Care Institutional Based Study

Background: Among general anesthesia induction drugs, etomidate is the only imidazole, and it has the most favourable therapeutic index for single bolus administration. Propofol is non-barbiturate short acting intravenous anaesthetic agent. It is a phenol derivative (2,6-Diisopropylphenol). Hence; the present study was undertaken for assessing the hemodynamic changes and complication occurring with propofol and etomidate during general anaesthesia. Materials & Methods: A total of 40 patients scheduled to undergo surgical procedure under general anesthesia were enrolled. All the patients were divided broadly into two study groups with 20 patients in each group as follows: Group 1: Propofol group, and Group 2: Etomidate group. Propofol group received propofol at 2 mg/kg and etomidate group received etomidate at 0.2 mg/kg. Pain on injection and myoclonic movements were recorded, if any at induction. As soon as the onset of unconsciousness occurs consumed dose of anaesthetic were recorded individually. All the results were recorded and analysed by SPSS software. Results: Mean heart rate among patients of group 1 at baseline, at induction and at 10 minutes was 85.6, 98.4 and 81.3 respectively. Mean heart rate among patients of group 2 at baseline, at induction and at 10 minutes was 84.2, 96.1 and 82.7 respectively. Mean arterial pressure among patients of group 1 at baseline, at induction and at 10 minutes was 89.3, 80.4 and 94.6 respectively. Mean arterial pressure among patients of group 2 at baseline, at induction and at 10 minutes was 90.1, 88.6 and 95.4 respectively. Significant results were obtained while comparing the mean arterial pressure at induction among the two study groups. Pain on injection was seen in 2 patients of group 1 and 1 patient of group 2. Conclusion: From the above results, the authors concluded that etomidate was better in comparison to propofol during general anaesthesia

Not Available

Not AvailableNot AvailableNot Availabl

Intercropping—A Low Input Agricultural Strategy for Food and Environmental Security

Intensive agriculture is based on the use of high-energy inputs and quality planting materials with assured irrigation, but it has failed to assure agricultural sustainability because of creation of ecological imbalance and degradation of natural resources. On the other hand, intercropping systems, also known as mixed cropping or polyculture, a traditional farming practice with diversified crop cultivation, uses comparatively low inputs and improves the quality of the agro-ecosystem. Intensification of crops can be done spatially and temporally by the adoption of the intercropping system targeting future need. Intercropping ensures multiple benefits like enhancement of yield, environmental security, production sustainability and greater ecosystem services. In intercropping, two or more crop species are grown concurrently as they coexist for a significant part of the crop cycle and interact among themselves and agro-ecosystems. Legumes as component crops in the intercropping system play versatile roles like biological N fixation and soil quality improvement, additional yield output including protein yield, and creation of functional diversity. But growing two or more crops together requires additional care and management for the creation of less competition among the crop species and efficient utilization of natural resources. Research evidence showed beneficial impacts of a properly managed intercropping system in terms of resource utilization and combined yield of crops grown with low-input use. The review highlights the principles and management of an intercropping system and its benefits and usefulness as a low-input agriculture for food and environmental security

Developing Rice with High Yield under Phosphorus Deficiency: Pup1 Sequence to Application1[W][OA]

The major quantitative trait locus (QTL) Phosphorus uptake1 (Pup1) confers tolerance of phosphorus deficiency in soil and is currently one of the most promising QTLs for the development of tolerant rice (Oryza sativa) varieties. To facilitate targeted introgression of Pup1 into intolerant varieties, the gene models predicted in the Pup1 region in the donor variety Kasalath were used to develop gene-based molecular markers that are evenly distributed over the fine-mapped 278-kb QTL region. To validate the gene models and optimize the markers, gene expression analyses and partial allelic sequencing were conducted. The markers were tested in more than 80 diverse rice accessions revealing three main groups with different Pup1 allele constitution. Accessions with tolerant (group I) and intolerant (group III) Pup1 alleles were distinguished from genotypes with Kasalath alleles at some of the analyzed loci (partial Pup1; group II). A germplasm survey additionally confirmed earlier data showing that Pup1 is largely absent from irrigated rice varieties but conserved in varieties and breeding lines adapted to drought-prone environments. A core set of Pup1 markers has been defined, and sequence polymorphisms suitable for single-nucleotide polymorphism marker development for high-throughput genotyping were identified. Following a marker-assisted backcrossing approach, Pup1 was introgressed into two irrigated rice varieties and three Indonesian upland varieties. First phenotypic evaluations of the introgression lines suggest that Pup1 is effective in different genetic backgrounds and environments and that it has the potential to significantly enhance grain yield under field conditions

Developing Rice with High Yield under Phosphorus Deficiency: Pup1 Sequence to Application1[W][OA]

The major quantitative trait locus (QTL) Phosphorus uptake1 (Pup1) confers tolerance of phosphorus deficiency in soil and is currently one of the most promising QTLs for the development of tolerant rice (Oryza sativa) varieties. To facilitate targeted introgression of Pup1 into intolerant varieties, the gene models predicted in the Pup1 region in the donor variety Kasalath were used to develop gene-based molecular markers that are evenly distributed over the fine-mapped 278-kb QTL region. To validate the gene models and optimize the markers, gene expression analyses and partial allelic sequencing were conducted. The markers were tested in more than 80 diverse rice accessions revealing three main groups with different Pup1 allele constitution. Accessions with tolerant (group I) and intolerant (group III) Pup1 alleles were distinguished from genotypes with Kasalath alleles at some of the analyzed loci (partial Pup1; group II). A germplasm survey additionally confirmed earlier data showing that Pup1 is largely absent from irrigated rice varieties but conserved in varieties and breeding lines adapted to drought-prone environments. A core set of Pup1 markers has been defined, and sequence polymorphisms suitable for single-nucleotide polymorphism marker development for high-throughput genotyping were identified. Following a marker-assisted backcrossing approach, Pup1 was introgressed into two irrigated rice varieties and three Indonesian upland varieties. First phenotypic evaluations of the introgression lines suggest that Pup1 is effective in different genetic backgrounds and environments and that it has the potential to significantly enhance grain yield under field conditions