Influence of staggered sown Spring sunflower (Helianthus Annuus L.) at varying intra–row spacing and applied–N on pre– and post–anthesis N dynamics and dry matter partitioning in Indo–Gangetic Plains Region

In current study, dry–matter accumulation (DMA), pre– and post–anthesis nitrogen (N) accumulation, N translocation (NT) and dry–matter partitioning by sunflower seeds was investigated under three sowing dates (January 20, February 10 & March 2), two intra–row spacings (30 & 24 cm) and four nitrogen doses (0, 45, 60 & 75 kg ha^–1) in two alluvial soils. Early sowing resulted in higher DMA and NT; leading to higher nitrogen use efficiency (NUE) that could be associated with higher pre–anthesis N accumulation. The closer intra–row spacing resulted in higher DMA by all plant parts except seed. Each graded N dose improved DMA, but improvement in dry–matter partitioning to seed was significant up to 60 and 75 kg N ha^–1 during 2014 and 2015, respectively owing to higher NT under respective treatments. NUE was highest at 60 kg N ha^–1 during both years.     

Amendment of Sugar Mill Wastewater Irrigation on Soil Biohydrological Properties and Yield of Vigna umguiculata L. Walp in Two Seasons

A field experiment was conducted to study the biohydrological properties of soil and yield of Vigna unguiculata L. Walp irrigated with five concentrations of sugar mill wastewater (SMW) during the Kharif and Zaid seasons. Among various concentrations of SMW, irrigation with 100% SMW significantly (P < 0.001) increased zinc (Zn), copper (Cu), cadmium (C), nickel (Ni), chromium (Cr), and iron (Fe) of the soil, while decreased total bacteria, fungi, actinomycetes, yeast, and rhizobia of the soil in both the cultivated seasons. However, the values of these metals were below the recommended permissible limit except Cd. Enrichment factor (Ef) of various heavy metals for soil was in the order Ni > Cr > Cd > Zn > Cu after irrigation with SMW. The crop yield of V. unguiculata was found to be inversely proportional to concentrations of SMW, with the best results being obtained at 50% SMW concentrations after 90 days of irrigation in both the cultivated seasons.     

Phytochemical composition of onion during long-term storage

Onion cultivar “Sunpower” has growing popularity in Korea due to high storability. The present study considers changes in flavonols, sugars, and two amino acids in onion bulbs during a long-term storage in the ambient dark storage room and in glasshouse equipped with a climate control system. Flavonol and sugar contents were found to fluctuate noticeably during the storage period. Amino acid content remained relatively unchanged till the onset of inner sprouting, increasing afterward. Visible sprouts appeared at week 22 in the dark storage room and for four weeks later in the glasshouse. The bulbs lost 20–30% of their weight depending on storage conditions at the end of the storage trials. At the same time, the content of nutraceutics in study expressed on the dry weight basis remained of the same order of magnitude. The nature of observed variations in chemical composition of onions as well as relation of this phenomenon to physiological development of stored onion bulbs is discussed. A conclusion is made that the “Sunpower” onion cannot sustain overwinter storage.     

Status and consolidated list of threatened medicinal plants of India

A wide array of medicinal plants in India, primarily used by locals for health care, have found wide acceptance and adoption globally (either directly or processed) due to distinct advantages of good results, low or no side-effects and ease of access to general public. Indigenous and traditional systems of medicine in practice since historical times have shown potential (direct or indirect as immune-boosters) against many dreaded ailments including the recent global pandemic of COVID-19. With prediction of sixth mass extinction, there is worldwide concern as majority of these plants, collected from natural stands, are also facing threat of extinction. Since 1990s concerted efforts have been directed towards assessment of threat status, the basic requirement for prioritizing conservation activity to various species of plants and animals. In literature there is staggered information regarding list of threatened plants, including medicinal plants of India, compiled at either state level or national or international level. Analysis of these publications led to collation of a consolidated list of 84 species and the same is presented here. A brief account of conservation efforts in India at national level and supportive policy framework is also included. This compilation is aimed to serve as a comprehensive reference especially for beginners, researchers, conservationists, foresters, pharmaceutical professionals as well as policy makers.

     

Interactive Effects of Cadmium and Zinc on Carrots: Growth and Biomass Accumulation

ABSTRACT

An experiment was carried out to assess the single and combined effects of cadmium (Cd) and zinc (Zn) on growth and component wise biomass accumulation in carrot (Daucus carota L.) plants, grown under natural field conditions. Carrot plants were raised in field and treated with 10 and 100 μ g mL^{? 1} of Cd, 100 and 300 μ g mL^{? 1} of Zn singly, and in combination through soil drench. A control was also kept without any treatments of Cd and Zn. The impacts of different treatments of Cd and Zn on carrots were evaluated in terms of number of leaves, leaf area, plant length, and component wise biomass accumulation at different plant ages. Growth indices were also calculated to assess the biomass allocation patterns in carrots. The results showed that the above parameters were significantly affected in carrots treated with Cd and Zn singly and in combination as compared to the control as well as plants treated with 100 μ g mL^{? 1} of Zn. The results also showed that treatments of Cd and Zn have significant effects on biomass allocation pattern. This study concludes that growth and biomass accumulation in carrots were significantly influenced by the concentration ratios of Cd and Zn in soil/root/stem/ leaves. It is clear from this study that combined treatments of Cd and Zn have more negative impacts on above parameters as compared to their individual treatments.     

Rice-wheat productivity and nutrient status in a lantana- (Lantana spp.) amended soil

Imbalanced and inadequate use of chemical fertilizers is responsible for low rice- (Oryza sativa L.) wheat (Triticum aestivum L.) productivity in many resource-poor farmers' fields. Wheat yields in post-rice soils are also constrained due to soil conditions created by puddling in rice, especially in fine to medium textured soils. Organic amendments are known to improve soil productivity under rice-wheat cropping by way of improving physical conditions and nutrient status of the soil, but their availability is restricted. There is a need to identify locally available and cost-effective organic materials, which have minimal alternate uses as fodder and fuel. We evaluated lantana (Lantana spp. L.) residues, a fast-growing weed in nearby wastelands, as a potential soil organic amendment. Yield trends, and soil and crop nutrient status in a 12-year rice-wheat experiment at Palampur, India, involving four levels (0, 10, 20, and 30 Mg ha^-1 year^-1 fresh mass) of lantana addition were investigated. Chopped lantana was incorporated into soil 10–15 days before puddling. Lantana additions at 10, 20 and 30 Mg ha^-1 increased rice yields on average by 18%, 23% and 30%, wheat yields by 11%, 14% and 20%, and total system productivity (rice + wheat) by 15%, 20% and 26% over controls, respectively, and at the same time saved NPK fertilizer. Linear regression analyses over 12 years did not show any change in yield trends of rice and wheat at P =0.05. Continuous cultivation of rice-wheat significantly increased total C, labile C, and other C indices of soils. Total N, Olsen's P, and NH₄OAc-extractable K in the lantana-amended plots were higher than in the controls. Nutrient concentrations in crop biomass, however, remained generally unaffected by lantana treatments. Results suggest that lantana residues, which improved the nutrient status of soil and system yield, have the potential for resource conservation and sustaining rice-wheat productivity.     

Polycyclic Aromatic Hydrocarbon Deposition in the Snowpack of the Athabasca Oil Sands Region of Alberta,Canada

In the Athabasca Oil Sands Region (AOSR) of Alberta, Canada, increased concentrations of polycyclic aromatic hydrocarbons (PAHs) in the regional ecosystems and downstream of oil sands development have been observed, presumably originating from various sources including those of oil sands and non-oil sands activities. In this study, we investigated the extent that oil sands activities contribute PAHs to the snowpack of the AOSR. The dominant groups of PAHs found in our snow samples were dibenzothiophenes, phenanthrenes/anthracenes, fluranthenes/pyrenes, chrysenes, and fluorenes. These PAHs were highly dominated by alkylated species, especially near oil sands operations. Aerial deposition of PAHs declined exponentially with increasing distance from the geographic center (GC), which was located close to Suncor and Syncrude’s oil sands operations. The higher aerial deposition at similar distances from GC in the N-S versus W-E directions reflects that PAH inputs from oil sands operations are clustered along the Athabasca River. Patterns of air parcel movements, derived from HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) modeling, closely matched patterns of aerial deposition, supporting that regional wind patterns influence the transport of PAHs emitted by oil sands operations in the AOSR. The source attribution techniques employed in this study revealed that sampling location influenced the characteristics of PAHs deposited. PAHs deposited at sites close to GC were associated with industrial activity, whereas the influences of other sources became increasingly apparent as distance increased from major oil sands areas.     

Characterization of <Emphasis Type="Italic">Prosopis cineraria</Emphasis> (L.) Druce germplasm with suitable horticultural traits from the hot arid region of Rajasthan,India

Sixteen germplasm accessions of Prosopis cineraria with suitable horticultural traits were identified from north-western Rajasthan, India, propagated clonally by budding on seedling rootstock and maintained in the field gene bank. Morphological characterization of seven-year-old trees of these accessions by 21 traits indicated a lot of variation among the accessions tested. Higher number of flowers per raceme was found in accession CIAH/K2, higher width of ripened pod in CIAH/K5, higher number of seeds per pod in CIAH/K12 and a higher weight of seed per pod in CIAH/K6. Overall, CIAH/K16 was found to be a superior genotype for most of the useful traits. High significant positive correlation was obtained with traits useful for horticultural values. Out of 62 random decamer primers for random amplification (RAPD) reaction, and four minisatellite core sequence for direct amplification of minisatellite DNA (DAMD) screened with these accessions, 12 RAPD and 2 DAMD primers were found polymorphic. Average polymorphism resolved by these markers among the accessions was 93.2%. Genetic diversity revealed by Jaccard’s co-efficient was between 0.11 and 0.77, and four major clusters were identified among these accessions by phylogenetic analysis using NTSYSpc-2.02e software. This study shows the existence of high genetic diversity within these accessions.     

The Alleviating Effect of Elevated CO2 on Heat Stress Susceptibility of Two Wheat (Triticum aestivum L.) Cultivars

This study analysed the alleviating effect of elevated CO₂ on stress‐induced decreases in photosynthesis and changes in carbohydrate metabolism in two wheat cultivars (Triticum aestivum L.) of different origin. The plants were grown in ambient (400 μl l^?1) and elevated (800 μl l^?1) CO₂ with a day/night temperature of 15/10 °C. At the growth stages of tillering, booting and anthesis, the plants were subjected to heat stress of 40 °C for three continuous days. Photosynthetic parameters, maximum quantum efficiency of photosystem II (PSII) photochemistry (F_v/F_m) and contents of pigments and carbohydrates in leaves were analysed before and during the stress treatments as well as after 1 day of recovery. Heat stress reduced P_N and F_v/F_m in both wheat cultivars, but plants grown in elevated CO₂ maintained higher P_N and F_v/F_m in comparison with plants grown in ambient CO₂. Heat stress reduced leaf chlorophyll contents and increased leaf sucrose contents in both cultivars grown at ambient and elevated CO₂. The content of hexoses in the leaves increased mainly in the tolerant cultivar in response to the combination of elevated CO₂ and heat stress. The results show that heat stress tolerance in wheat is related to cultivar origin, the phenological stage of the plants and can be alleviated by elevated CO₂. This confirms the complex interrelation between environmental factors and genotypic traits that influence crop performance under various climatic stresses.     

Marker‐assisted backcross breeding to combine multiple rust resistance in wheat

A widely grown but rust susceptible Indian wheat variety HD2932 was improved for multiple rust resistance by marker‐assisted transfer of genes Lr19, Sr26 and Yr10. Foreground and background selection processes were practised to transfer targeted genes with the recovery of the genome of HD2932. The near‐isogenic lines (NILs) of HD2932 carrying Lr19, Sr26 and Yr10 were individually produced from two backcrosses with recurrent parent HD2932. Marker‐assisted background selection of NILs with 94.38–98.46% of the HD2932 genome facilitated rapid recovery of NILs carrying Lr19, Sr26 and Yr10. In the BC₂F₂ generation, NILs were intercrossed and two gene combinations of Lr19+Yr10, Sr26 + Yr10 and Lr19+Sr26 were produced. A total of 16 progeny of two gene combinations of homozygous NILs of HD2932 have been produced, which are under seed increase for facilitating the replacement of the susceptible HD2932 with three of the sixteen improved backcross lines with resistance to multiple rusts.