163 research outputs found
Enhancement of drought-induced senescence by the reproductive sink in fertile lines of wheat and Sorghum
The leaf senescence pattern was examined in water-stressed male sterile and fertile lines of wheat (Triticum aestivum) and sorghum (Sorghum vulgare). The study was conducted at the seedling stage and during grain development. The loss of leaf area and chlorophyll content induced by water stress was similar in the male sterile and fertile lines of wheat at the seedling stage. At the grain filling stage, leaf senescence occurred at a faster rate in the fertile lines as compared to sterile lines of both wheat and sorghum. The study indicates that a reproductive sink accentuates drought-induced leaf senescence
A comparison of physiological and yield characters in old and new wheat varieties
The Indian subcontinent has witnessed a spectacular improvement in yield of wheat during the past decade (Rao, 1978). This is reflected in the improvement of the average national yields as well as of those regions where wheat is grown as an irrigated crop (Sinha & Aggarwal, 1981). However, after the release of the double dwarf variety Kalyansona, only marginal improvement in yield has occurred in recent years. Despite this, the semi-dwarf character continues to be considered a major factor for improvement of wheat. Asana & Chattopadhyay (1970), Konar & Asana (1975), and Wattal & Asana (1976) observed no significant difference in yield between tall and semi-dwarf (medium tall) varieties in pot culture experiments where lodging was prevented and competition was partly reduced. They ascribed prevention from lodging and improvement in the ratio of grain to total above-ground dry matter as major advantages in the modern varieties. Somewhat similar conclusions have recently been drawn by Austin et al. (1980). However, a detailed comparison of various physiological and biochemical characters lias not been made to determine whether any advance has occurred in basic processes such as photosynthesis and nitrogen assimilation. The present study was an effort in this direction
Human health risk assessment of temporal and spatial variations of ground water quality at a densely industrialized commercial complex at Haridwar, India
The observations of present investigation revealed that the groundwater regime at State Infrastructure and Industrial Development Corporation of Uttarakhand Limited (SIDCUL) Industrial Estate (IE) was highly responsive to the anthropogenic stress of recharge and discharge parameters concerning the distressing industrial activities. The present study on groundwater characteristics of SIDCUL-IE, Haridwar in year 2013-2014 showed that the water of Sampling station-D (SSD) had relatively poor quality in comparison to the groundwater collected from Sampling station-A (SSA), Sampling station-B (SSB) and Sampling station-C (SSC). The samples had a high mineral load with relatively wider pH range. The physico-chemical parameters like pH (6.35 in October) at SSA, TDS (553.5 mg/l in November) at SSC, TH (600.0 mg/l in July) at SSB and alkalinity (525.0 mg/l in October) at SSD were beyond the prescribed limits of Bureau of Indian Standards (BIS). The Karl Pearson correlation matrix showed moderate to significantly positive correlation between various parameters like COD-phosphorus (r=0.629), temperature-DO (r=-0.477) at SSA; pH and bicarbonate (r=0.668) at SSB; pH-temperature (r=-0.551),turbidity-BOD (r=0.467), BOD-phosphorus (r=0.518), bicarbonate-acidity (r=-0.833) at SSC and TSS-turbidity (r=0.616), BOD-COD (r=0.6771) at SSD and temperature-DO (r=-0.666), hardness-acidity (r=-0.6542) BOD-COD (r=0.654) at control site. The overall quality of groundwater, though hard, was found acceptable for drinking purpose. The divergence in the results of groundwater samples taken from SIDCUL-IE and the Control site, 2 km away from SIDCUL-IE, indicated that groundwater pollution is increasing alarmingly which may have serious threats to human health in near future
Autoimmune Response as a Mechanism for a Dobzhansky-Muller-Type Incompatibility Syndrome in Plants
Epistatic interactions between genes are a major factor in evolution. Hybrid necrosis is an example of a deleterious phenotype caused by epistatic interactions that is observed in many intra- and interspecific plant hybrids. A large number of hybrid necrosis cases share phenotypic similarities, suggesting a common underlying mechanism across a wide range of plant species. Here, we report that approximately 2% of intraspecific crosses in Arabidopsis thaliana yield F1 progeny that express necrosis when grown under conditions typical of their natural habitats. We show that several independent cases result from epistatic interactions that trigger autoimmune-like responses. In at least one case, an allele of an NB-LRR disease resistance gene homolog is both necessary and sufficient for the induction of hybrid necrosis, when combined with a specific allele at a second locus. The A. thaliana cases provide insights into the molecular causes of hybrid necrosis, and serve as a model for further investigation of intra- and interspecific incompatibilities caused by a simple epistatic interaction. Moreover, our finding that plant immune-system genes are involved in hybrid necrosis suggests that selective pressures related to host–pathogen conflict might cause the evolution of gene flow barriers in plants
Heat and water stress induce unique transcriptional signatures of heat-shock proteins and transcription factors in grapevine
Grapevine is an extremely important crop worldwide.
In southern Europe, post-flowering phases of the growth
cycle can occur under high temperatures, excessive light, and
drought conditions at soil and/or atmospheric level. In this
study, we subjected greenhouse grown grapevine, variety
Aragonez, to two individual abiotic stresses, water deficit stress
(WDS), and heat stress (HS). The adaptation of plants to stress
is a complex response triggered by cascades of molecular
networks involved in stress perception, signal transduction,
and the expression of specific stress-related genes and metabolites.
Approaches such as array-based transcript profiling allow
assessing the expression of thousands of genes in control
and stress tissues. Using microarrays, we analyzed the leaf
transcriptomic profile of the grapevine plants. Photosynthesis
measurements verified that the plants were significantly affected
by the stresses applied. Leaf gene expression was obtained
using a high-throughput transcriptomic grapevine array, the
23K custom-made Affymetrix Vitis GeneChip. We identified
1,594 genes as differentially expressed between control and
treatments and grouped them into ten major functional categories
using MapMan software. The transcriptome of Aragonez
was more significantly affected by HS when compared with
WDS. The number of genes coding for heat-shock proteins and
transcription factors expressed solely in response to HS suggesting
their expression as unique signatures of HS. However, a cross-talk between the response pathways to both stresses was
observed at the level of AP2/ERF transcription factors
Inheritance and relationships of flowering time and seed size in kabuli chickpea
Flowering time and seed size are the important traits for adaptation in chickpea. Early phenology (time of flowering, podding and maturity) enhance chickpea adaptation to short season environments. Along with a trait of consumer preference, seed size has also been considered as an important factor for subsequent plant growth parameters including germination, seedling vigour and seedling mass. Small seeded kabuli genotype ICC 16644 was crossed with four genotypes (JGK 2, KAK 2, KRIPA and ICC 17109) to study inheritance of flowering time and seed size. The relationships of phenology with seed size, grain yield and its component traits were studied. The study included parents, F1, F2 and F3 of four crosses. The segregation data of F2 indicated flowering time in chickpea was governed by two genes with duplicate recessive epistasis and lateness was dominant to earliness. Two genes were controlling 100-seed weight where small seed size was dominant over large seed size. Early phenology had significant negative or no association (ICC 16644 × ICC 17109) with 100-seed weight. Yield per plant had significant positive association with number of seeds per plant, number of pods per plant, biological yield per plant, 100-seed weight, harvest index and plant height and hence could be considered as factors for seed yield improvement. Phenology had no correlation with yield per se (seed yield per plant) in any of the crosses studied. Thus, present study shows that in certain genetic background it might be possible to breed early flowering genotypes with large seed size in chickpea and selection of early flowering genotypes may not essentially have a yield penalty
Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study
Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk
Global estimates on the number of people blind or visually impaired by cataract: a meta-analysis from 2000 to 2020
Background: To estimate global and regional trends from 2000 to 2020 of the number of persons visually impaired by cataract and their proportion of the total number of vision-impaired individuals. Methods: A systematic review and meta-analysis of published population studies and gray literature from 2000 to 2020 was carried out to estimate global and regional trends. We developed prevalence estimates based on modeled distance visual impairment and blindness due to cataract, producing location-, year-, age-, and sex-specific estimates of moderate to severe vision impairment (MSVI presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60). Estimates are age-standardized using the GBD standard population. Results: In 2020, among overall (all ages) 43.3 million blind and 295 million with MSVI, 17.0 million (39.6%) people were blind and 83.5 million (28.3%) had MSVI due to cataract blind 60% female, MSVI 59% female. From 1990 to 2020, the count of persons blind (MSVI) due to cataract increased by 29.7%(93.1%) whereas the age-standardized global prevalence of cataract-related blindness improved by −27.5% and MSVI increased by 7.2%. The contribution of cataract to the age-standardized prevalence of blindness exceeded the global figure only in South Asia (62.9%) and Southeast Asia and Oceania (47.9%). Conclusions: The number of people blind and with MSVI due to cataract has risen over the past 30 years, despite a decrease in the age-standardized prevalence of cataract. This indicates that cataract treatment programs have been beneficial, but population growth and aging have outpaced their impact. Growing numbers of cataract blind indicate that more, better-directed, resources are needed to increase global capacity for cataract surgery.</p
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