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•CNT-EBAC based novel adsorbent is developed via a novel process.•CNT-EBAC is used as an adsorbent for the removal of MB and EY from waste water.•The adsorbent removed more than 90% ...of dyes in less than 60 min.•This adsorbent is highly promising for water decontamination applications.
Carbon nanotube (CNT) incorporated eucalyptus derived activated carbon-based novel adsorbent is synthesized by a novel route. This adsorbent is investigated for the removal of two different dyes; methylene blue (MB) and eosin yellow (EY) from the waste water. The effect of pH, adsorbent dose, contact time and initial concentration, has been used to measure the dye removal efficiency of the adsorbent. Langmuir isotherm, Freundlich isotherm and D-R isotherm models were used to fit the experimental dye adsorption data, with the D-R model providing the best fit. The maximum adsorption efficiency of adsorbent for MB and EY removal is 49.61 and 49.15 mg/g, respectively. Reaction kinetics studies were also established to further investigate the dye adsorption mechanism. It is observed that pseudo second order model define the reaction kinetics involved in the reaction. This activated carbon adsorbent based on CNTs is shown to be highly promising for water decontamination applications.
QTLs for rice grain yield under reproductive stage drought stress (qDTY) identified earlier with low density markers have shown linkage drag and need to be fine mapped before their utilization in ...breeding programs. In this study, genotyping-by-sequencing (GBS) based high-density linkage map of rice was developed using two BC
F
mapping populations namely Swarna*2/Dular (3929 SNPs covering 1454.68 cM) and IR11N121*2/Aus196 (1191 SNPs covering 1399.68 cM) with average marker density of 0.37 cM to 1.18 cM respectively. In total, six qDTY QTLs including three consistent effect QTLs were identified in Swarna*2/Dular while eight qDTY QTLs including two consistent effect QTLs were identified in IR11N121*2/Aus 196 mapping population. Comparative analysis revealed four stable and novel QTLs (qDTY
, qDTY
, qDTY
, and qDTY
) which explained 8.62 to 14.92% PVE. However, one of the identified stable grain yield QTL qDTY
in both the populations was located nearly at the same physical position of an earlier mapped major qDTY QTL. Further, the effect of the identified qDTY
was validated in a subset of lines derived from five mapping populations confirming robustness of qDTY
across various genetic backgrounds/seasons. The study successfully identified stable grain yield QTLs free from undesirable linkages of tall plant height/early maturity utilizing high density linkage maps.
Biochar is a carbon-rich stable product derived from the thermochemical decomposition of biomass. The properties of biochar vary with types of feedstock, heating rate, pyrolysis temperature, etc. ...Consequently, the mechanical and hydrological properties of biochar amended soil (BAS) also differ with types of biochar and soils. However, the effect of bamboo biochar (BB) amendment on soil strength and water retention properties is missing in the previous literature. Bamboo biomass was pyrolysed at 600 °C to produce biochar. BB and soils (low plastic clay (CL) and silty sand (SM)) were mixed to prepare BAS. The samples were prepared by mixing BB in five ratios, i.e., 0%, 1%, 2%, 3.5% and 5% of dry soil weight. The biochar application has increased optimum moisture content, alkalinity (pH) and Atterberg limits, whereas, reduced maximum dry density and specific gravity of both the soils (CL and SM). The unconfined compressive strength (UCS) of CL soil was noted to increase by 10.5% with 2% biochar content and decreased after that, whereas the UCS of SM soil was found to decrease continuously with the biochar content increment. Therefore, the unconfined compressive strength (UCS) result showed that biochar application has contrary effects on both soils. The measured gravimetric water content (GWC) of BAS was increased with biochar increment in both soils. However, GWC increased more in CL than in SM soil at the same biochar content. The microstructural analysis showed that the biochar amendment filled the pore space of the soil matrix, resulting in an increase in UCS and GWC values. The increased water retention capacity and strength (UCS) of biochar amended CL soil provides evidence that it could be used as a landfill cover material.
Abstract
Occurrence of multiple abiotic stresses in a single crop season has become more frequent than before. Most of the traditional donors possessing tolerance to abiotic stresses are tall, ...low-yielding with poor grain quality. To facilitate efficient use of complex polygenic traits in rice molecular breeding research, we undertook development of introgression lines in background of high-yielding, semi-dwarf varieties with good grain quality. The study reports the development and evaluations of over 25,000 introgression lines in eleven elite rice genetic backgrounds for improvement of yield under multiple abiotic-stresses such as drought, flood, high/low temperature. The developed introgression lines within each genetic background are near isogenic/recombinant inbred lines to their recipient recurrent parent with 50 to 98% background recovery and additionally carry QTLs/genes for abiotic stresses. The multiple-stress tolerant pyramided breeding lines combining high yield under normal situation and good yield under moderate to severe reproductive-stage drought, semi-dwarf plant type with good grain quality traits have been developed. The introgression lines in dwarf backgrounds open new opportunity to improve other varieties without any linkage drag as well as facilitate cloning of QTLs, identification and functional characterization of candidate genes, mechanisms associated with targeted QTLs and the genetic networks underlying complex polygenic traits.
Napin and napin-like proteins belong to the 2S albumin seed storage family of proteins and have been shown to display a variety of biological activities. However, due to a high degree of ...polymorphism, purification of a single napin or napin-like protein exhibiting biological activity is extremely difficult. In the present study, we have produced the napin-like protein of
Momordica charantia
using the methylotrophic
Pichia pastoris
expression system. The recombinant napin-like protein (rMcnapin) secreted in the extracellular culture supernatant was enriched by ammonium sulfate precipitation, and purified using size exclusion chromatography at a yield of ∼290 mg/L of culture. Secondary structure analysis of the purified rMcnapin revealed it to be predominantly α-helical with minimal β strand content. CD spectroscopic and fluorescence spectroscopic analyses revealed the rMcnapin to be stable at a wide range of temperatures and pH. The rMcnapin exhibited antifungal activity against
Trichoderma viride
with an IC
50
of ∼3.7 μg/ml and trypsin inhibitor activity with an IC
50
of 4.2 μM. Thus, large amounts of homogenous preparations of the biologically active rMcnapin could be obtained at shake flask level, which is otherwise difficult from its natural source.
Background
Unfavorable climatic changes have led to an increased threat of several biotic and abiotic stresses over the past few years. Looking at the massive damage caused by these stresses, we ...undertook a study to develop high yielding climate-resilient rice, using genes conferring resistance against blast (
Pi9
), bacterial leaf blight (BLB) (
Xa4, xa5, xa13, Xa21
), brown planthopper (BPH) (
Bph3, Bph17
), gall midge (GM) (
Gm4, Gm8
) and QTLs for drought tolerance (
qDTY
1.1
and
qDTY
3.1
) through marker-assisted forward breeding (MAFB) approach.
Result
Seven introgression lines (ILs) possessing a combination of seven to ten genes/QTLs for different biotic and abiotic stresses have been developed using marker-assisted selection (MAS) breeding method in the background of Swarna with drought QTLs. These ILs were superior to the respective recurrent parent in agronomic performance and also possess preferred grain quality with intermediate to high amylose content (AC) (23–26%). Out of these, three ILs viz., IL1 (
Pi9
+
Xa4
+
xa5
+
Xa21
+
Bph17
+
Gm8
+
qDTY
1.1
+
qDTY
3.1
), IL6 (
Pi9
+
Xa4
+
xa5
+
Xa21
+
Bph3
+
Bph17
+
Gm4
+
Gm8+ qDTY
1.1
+
qDTY
3.1
) and IL7 (
Pi9+ Xa4
+
xa5
+
Bph3
+
Gm4
+
qDTY
1.1
+
qDTY
3.1
) had shown resistance\tolerance for multiple biotic and abiotic stresses both in the field and glasshouse conditions. Overall, the ILs were high yielding under various stresses and importantly they also performed well in non-stress conditions without any yield penalty.
Conclusion
The current study clearly illustrated the success of MAS in combining tolerance to multiple biotic and abiotic stresses while maintaining higher yield potential and preferred grain quality. Developed ILs with seven to ten genes in the current study showed superiority to recurrent parent Swarna+drought for multiple-biotic stresses (blast, BLB, BPH and GM) together with yield advantages of 1.0 t ha
− 1
under drought condition, without adverse effect on grain quality traits under non-stress.
There is an urgent need to breed dry direct-seeded adapted rice varieties in order to address the emerging scenario of water-labor shortage. The aim of this study was to develop high-yielding, ...direct-seeded adapted varieties utilizing biparental to multiparental crosses involving as many as six different parents in conventional breeding programs and 12 parents in genomics-assisted breeding programs. The rigorous single plant selections were followed from the F
generation onwards utilizing phenotypic selection and quantitative trait locus (QTL)/gene-based/linked markers for tracking the presence of desirable alleles of targeted QTL/genes. In conventional breeding, multiparent lines had significantly higher yields (2,072-6,569 kg ha
) than the biparental lines (1,493-6,326 kg ha
). GAB lines derived from multiparent crosses had significantly higher (3,293-6,719 kg ha
) yields than the multiparent lines from conventional breeding (2,072-6,569 kg ha
). Eleven promising lines from genomics-assisted breeding carrying 7-11 QTL/genes and eight lines from conventional breeding with grain-yield improvement from 727 to 1,705 kg ha
and 68 to 902 kg ha
, respectively, over the best check were selected. The developed lines may be released as varieties/parental lines to develop better rice varieties for direct-seeded situations or as novel breeding material to study genetic interactions.
Characterization of physiological traits affected by rice breeding for grain yield under drought conditions shows that atmospheric and soil stresses strengthen the relationship between leaf traits ...and yield across extensive trials in South Asia.
Abstract
Direct selection for yield under drought has resulted in the release of a number of drought-tolerant rice varieties across Asia. In this study, we characterized the physiological traits that have been affected by this strategy in breeding trials across sites in Bangladesh, India, and Nepal. Drought- breeding lines and drought-tolerant varieties showed consistently longer flag leaves and lower stomatal density than our drought-susceptible check variety, IR64. The influence of environmental parameters other than drought treatments on leaf traits was evidenced by close grouping of treatments within a site. Flag-leaf length and width appeared to be regulated by different environmental parameters. In separate trials in the Philippines, the same breeding lines studied in South Asia showed that canopy temperature under drought and harvest index across treatments were most correlated with grain yield. Both atmospheric and soil stress strengthened the relationships between leaf traits and yield. The stable expression of leaf traits among genotypes and the identification of the environmental conditions in which they contribute to yield, as well as the observation that some breeding lines showed longer time to flowering and higher canopy temperature than IR64, suggest that selection for additional physiological traits may result in further improvements of this breeding pool.
The elite Indian rice variety, Naveen is highly susceptible to major biotic and abiotic stresses such as blast, bacterial blight (BB), gall midge (GM) and drought which limit its productivity in ...rainfed areas. In the present study, a combined approach of marker-assisted forward (MAFB) and back cross (MABC) breeding was followed to introgress three major genes, viz., Pi9 for blast, Xa21 for bacterial blight (BB), and Gm8 for gall midge (GM) and three major QTLs, viz., qDTY.sub.1.1, qDTY.sub.2.2 and qDTY.sub.4.1 conferring increased yield under drought in the background of Naveen. At each stage of advancement, gene-based/linked markers were used for the foreground selection of biotic and abiotic stress tolerant genes/QTLs. Intensive phenotype-based selections were performed in the field for identification of lines with high level of resistance against blast, BB, GM and drought tolerance without yield penalty under non-stress situation. A set of 8 MAFB lines and 12 MABC lines with 3 to 6 genes/QTLs and possessing resistance/tolerance against biotic stresses and reproductive stage drought stress with better yield performance compared to Naveen were developed. Lines developed through combined MAFB and MABC performed better than lines developed only through MAFB. This study exemplifies the utility of the combined approach of marker-assisted forward and backcrosses breeding for targeted improvement of multiple biotic and abiotic stress resistance in the background of popular mega varieties.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Epistatic interactions of QTLs with the genetic background and QTL-QTL interaction plays an important role in the phenotypic performance of introgression lines developed through genomic-assisted ...breeding (GAB). In this context, NIL pairs developed with various drought QTL (qDTY) combinations in the genetic background of IR64, TDK1-Sub1 and Savitri backgrounds were utilized to study the interactions. Multi-season phenotyping of NIL pairs harboring similar qDTY combinations provided contrasting performance for grain yield under drought (RS) (classified as high and low yielding NILs) but nearly similar performance under non-stress(NS) conditions. Genome wide genotyping data revealed a total of 16, 5 and 6 digenic interactions were detected under RS conditions in low yielding NILs of IR64, TDK1-Sub1 and Savitri respectively while no significant interaction was found in high yielding NILs under RS and NS conditions in any of the genetic backgrounds used in this study. It is evident from this study that existence of epistatic interactions between QTLs with genetic background, QTL-QTL interaction and interactions among background markers loci itself on different chromosomes influences the expression of a complex trait such as grain yield under drought. The generated information will be useful in all the GAB program of across the crops for precise breeding.
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