Search Results (7)

Field pea is one of the important short-duration cool season pulse crops which contributes significantly towards food and nutritional security. Two heat-susceptible (HS) and two heat-tolerant (HT) genotypes were selected from the previous study for further characterization. A significant variation was observed for morpho-physiological traits studied. Principal component analysis explained that first two principal components, i.e., PC1 and PC2 showed 76.5% of the total variance in optimal condition, whereas 91.2% of the total variance was covered by the first two PCs in heat stress environment. The seed yield per plant determined significant and positive association with superoxide dismutase and number of seeds per pod under optimal conditions, whereas under heat stress condition, it was positively associated with number of effective pods per plant, biological yield per plant, proline, pod length, number of seeds per pod, superoxide dismutase, and peroxidase. The significant reduction was noticed in the susceptible genotypes, whereas tolerant genotypes showed stable and non-significant reduction in chlorophyll content. Further, minimum cell damage and higher hydrogen peroxide production was noticed in the susceptible genotypes. In addition, the biochemical characterization of HS and HT genotypes revealed that the higher expression of peroxidase, superoxide dismutase, and catalase modulates the tolerant responses in HT genotypes. These genotypes were further used in developing heat-tolerant field pea genotypes. Full article

Salt tolerance mechanisms are regulated by balance in cell ionic concentrations such as K⁺, Na⁺, H⁺, Ca²⁺, and Mg²⁺. In this study, we examined major QTLs for the traits K⁺/Na⁺ homeostasis, shoot magnesium content (Mg²⁺), shoot calcium content (Ca²⁺), and shoot length. The QTLs for K⁺/Na⁺ homeostasis Sod K/Na.1 are associated with three candidate genes: LOC_Os02g48290, LOC_Os02g48340, and LOC_Os02g48350, and Sod_Ca.1 is associated with the gene LOC_Os08g15020. Three significant candidate gene haplotypes for shoot length, Sod_SL.1 (LOC_Os10g36690), sodium content Sod_Na.1 (LOC_Os01g41770), and magnesium content Sod_Mg.1 (LOC_Os10g31040) were identified. The identified candidate genes encode dehydration response proteins, leucine rich repeat proteins, citrate transporter proteins, and diacylglycerol O-acyltransferase (DGATs), and play a key role in salt and abiotic stress tolerance. The identified novel QTLs and potential candidate genes could be used for functional characterization to help further supplement our understanding of the genetic makeup of sodicity stress tolerance in rice. Full article

Rice is sensitive to salinity at both the seedling and reproductive stages, and it reduces the grain yield from 50 to 100%. In this study, 27 SNP markers significantly associated with 15 QTLs were identified. Three major QTLs were associated with shoot length (Sal_SL 7.1), shoot sodium content (Sal_Na 1.1) and shoot magnesium content (Sal_Mg 2.1). Five QTLs for root length (Sal_RL 1.1, Sal_RL 3.1, Sal_RL 6.1 Sal_RL 8.1 and Sal_RL 12.1), shoot K⁺/Na⁺ homeostasis (Sal_K/Na 1.1, Sal_K/Na 4.1, Sal_K/Na 5.1, Sal_K/Na 7.1 and Sal_K/Na 10.1) and single QTLs for shoot potassium (Sal_K 6.1) and calcium content (Sal_Ca 5.1) were also detected. QTL Sal_K/Na 1.1 was found responsible for the ionic ratio associated with the Saltol region, and Sal_K/Na 10.1 was associated with the gene OSCA1;4, which is a hyperosmolality-gated calcium-permeable channel that acts as an osmosensor under salt stress condition. A candidate gene haplotype analysis revealed ten significant genes, LOC_Os06g03940, LOC_Os10g42820, LOC_Os07g36230, LOC_Os02g06410, LOC_Os06g48610, LOC_Os12g12950, LOC_Os03g12050, LOC_Os08g02690, LOC_Os07g47560, and LOC_Os05g08840, responsible for abiotic stress tolerance. The identified potential candidate genes can be used for functional characterization to understand the complex mechanism of salinity tolerance in rice. Full article

Among abiotic stresses, salt stress is the most complicated problem posing a major challenge for maintaining world food supplies as well as food security as it covers 1125 m ha globally and 6.73 m ha in India. It is very essential to increase rice productivity in salt-affected soils for food security and sustainability in salt-affected environments. The pass port data of 9000 rice Germplasm has been established for 30 traits and a mini core of 1500 lines has been developed. Approximately 20,000 rice lines have been screened for salinity and sodicity for both seedling and reproductive stages. The highly tolerant rice lines are being used in breeding programme to enhance the genetic diversity. The six QTLs in chromosomes 1, 2, 8, 9, 10 has been identified for the Na/K ratio, spikelet fertility and grain yield for the reproductive stage salt tolerance. The Saltol QTL has been transferred to Indian mega rice varieties namely, Pusa44 and Sarjoo52, to improve the salinity tolerance at the seedling stage. Similarly, the qSSISFHS8.1 (QTL for spikelet fertility) QTL is being transferred into mega rice varieties namely, PR114, Pusa44 and Sarjoo52, to improve the salinity tolerance at the reproductive stage. The marker assisted selection accelerates the breeding activities to develop the salt-tolerant varieties as well as transfer the QTLs to HVYs through marker assisted back cross breeding. The Central Soil Salinity Research Institute (CSSRI) has developed 13 salt-tolerant rice varieties, namely CSR10, CSR13, CSR23, CSR27, Basmati CSR30, CSR36, CSR43, CSR46, CSR49, CSR52, CSR56, CSR60 and CSR76, through conventional breeding approaches to increase the productivity of salt-affected soils for resource poor farmers. The popularity of these salt-tolerant rice varieties can be ascertained from the facts that large quantity of breeder seeds (1056 quintals) and truthfully labelled seeds (3126 quintals) has been produced and sold during last 22 years (2000–2021), more demand from the farmers and large area app. One point two million hectares is covered by these salt-tolerant rice varieties every year. Numerous salt-tolerant rice lines are being developed at CSSRI to cope with salt-affected soils and enable sustainable agriculture under salt-affected soils. Full article

A novel synthetic method has been developed by utilizing the chemical reactivity of functionalized graphene and CNT with a covalent combination of chemically diverse GO/FCNT and toluene diisocyanate, thereby yielding a synergistic polymer nanocomposite. Comprehensive composite material has simultaneous covalent, as well as π-π, interactions confirming sp2-hybridized frameworks of graphene oxide and MWCNTs by Raman absorption spectra at 1345 and 1590 cm⁻¹ of D and G bands, respectively. Toluene diisocyanate and GO/FCNT inspired polymeric formulation was obtained by the classical curing reaction initiated by ultrasound sonication. This method allowed 50 wt.% doping of GO/FCNT without segregation and ensured good adhesion to the law steel surface. The large surface area and morphological character of GO and FCNT by SEM and TEM ensure stable and dispersed integrated molecules. This has advantages over high-temperature and hazardous curing reaction, and overcomes the problem of graphene exfoliation. It also does not allow CNT slipping within the bundle, which can cause falling apart at higher concentration. Full article

To explore the comparative effects of field sodicity (soil pH) and irrigation water residual alkalinity (RSC_iw) on physiological and biochemical attributes of salt tolerance, and crop performance of two wheat varieties (KRL 210, HD 2967), a total of 308 on-farm trials were carried out in sodicity affected Ghaghar Basin of Haryana, India. Salt tolerant variety KRL 210 maintained relatively higher leaf relative water content (RWC; 1.9%), photosynthetic rate (Pn; 5.1%), stomatal conductance (gS; 6.6%), and transpiration (E; 4.1%) with lower membrane injury (MII; −8.5%), and better control on accumulation of free proline (P; −18.4%), Na⁺/K⁺ in shoot (NaK_S; −23.1%) and root (NaK_R; −18.7%) portion compared to traditional HD 2967. Altered physiological response suppressed important yield-related traits revealing repressive effects of sodicity stress on wheat yields; albeit to a lesser extent in KRL 210 with each gradual increase in soil pH (0.77–1.10 t ha⁻¹) and RSC_iw (0.29–0.33 t ha⁻¹). HD 2967 significantly outyielded KRL 210 only at soil pH ≤ 8.2 and RSC_iw ≤ 2.5 me L⁻¹. By comparisons, substantial improvements in salt tolerance potential of KRL 210 with increasing sodicity stress compensated in attaining significantly higher yields as and when soil pH becomes >8.7 and RSC_iw > 4 me L⁻¹. Designing such variety-oriented threshold limits of sodicity tolerance in wheat will help address the challenge to enhance crop resilience, closing the yield gaps and improve rural livelihood under the existing or predicted levels of salt stress. Full article

Heavy metals from various natural and anthropogenic sources are becoming a chief threat to the aquatic system owing to their toxic and lethal effect. The treatment of such contaminated wastewater is one of the prime concerns in this field. For decades, a huge array of innovative biosorbents is used for heavy metal removal. Though extensive microbes and their biomolecules have been experimented and have showed great potential but most of them have failed to have the substantial breakthrough for the practical application. The present review emphasis on the potential utilization of the cyanobacteria for the heavy metal removal along with the toxic effect imposed by the pollutant. Furthermore, the effect of significant parameters, plausible mechanistic insights of the heavy metal toxicity imposed onto the cyanobacteria is also discussed in detail. The role of extrapolymeric substances and metallothionein secreted by the microbes are also elaborated. The review was evident that the cyanobacterial species have a huge potential towards the heavy metal removal from the aqueous system ranging from very low to very high concentrations. Full article