Pollen morphological investigation of selected species of family Asteraceae from Pakistan by using light and scanning electron microscopy.

A light and scanning electron microscopy technique was conducted to investigate the palynological features of 19 species belonging to 15 genera of the family Asteraceae. The species under investigation yielded pollen in a range of shapes, including spheroidal, prolate, and subprolate. Trizoncolporate, Tricolporate, and Tetracolporate are the three types of pollen apertures observed in examined species. Except for Gazania rigens, which has reticulate ornamentation under SEM, the exine pattern in all studied species is echinate. The majority of the species had isopolar polarity, whereas some members were apolar and heteropolar. The quantitative parameters that are polar to equatorial diameter, P/E ratio, length of colpi, width of colpi, length of the spine, width of spine, and exine thickness was measured by using light microscopy. The Coreopsis tinctoria had the lowest mean polar 19.75 µm to mean equatorial diameter 18.25 µm while the Silybum marianum had the highest polar 44.7 µm to equatorial 48.2 µm value. The value for colpi length/width was highest in Cirsium arvensis and lowest in C. tinctoria, measuring 9.7/13.2 µm and 2.7/4.7 µm, respectively. The spine length varied from 0.5 µm in Sonchus arvensis to 5.5 µm in Calendula officinalis. Verbesina encelioides had the highest exine thickness measurement (3.3 µm), whereas S. arvensis had the lowest (0.3 µm). The pollen surface of Tagetes erectus, has the highest number (65) whereas the lowest spines number (20) is found in S. arvensis. A taxonomic key based on pollen traits is provided for quick identification of the species. Significant implications for the systematics of the Asteraceae family can be drawn from the reported pollen's quantitative and qualitative data. RESEARCH HIGHLIGHTS: SEM and LM technique was used to study the palynological features of pollen grains. Quantitative and qualitative pollen features of 19 species of family Asteraceae are described. Morphological traits of pollen grains are important for the systematics of family Asteraceae.

Short-term responses of Spinach (Spinacia oleracea L.) to the individual and combinatorial effects of Nitrogen, Phosphorus and Potassium and silicon in the soil contaminated by boron.

While of lesser prevalence than boron (B) deficient soils, B-rich soils are important to study as they can cause B toxicity in the field and subsequently decrease crop yields in different regions of the world. We have conducted the present study to examine the role of the individual or combined application of silicon (Si) and NPK fertilizer in B-stressed spinach plants (Spinacia oleracea L.). S. oleracea seedlings were subjected to different NPK fertilizers, namely, low NPK (30 kg ha-2) and normal NPK (60 kg ha-2)], which were also supplemented by Si (3 mmol L-1), for varying levels of B in the soil i.e., 0, 250, and 500 mg kg-1. Our results illustrated that the increasing levels of B in the soil caused a substantial decrease in the plant height, number of leaves, number of stems, leaf area, plant fresh weight, plant dry weight, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid content, net photosynthesis, stomatal conductance, transpiration rate, magnesium content in the roots, magnesium contents in the shoots, phosphorus content in the roots, phosphorus content in the leaves in the shoots, iron content in the roots, iron content in the shoots, calcium content in the roots, and calcium content in the shoots. However, B toxicity in the soil increased the concentration of malondialdehyde, hydrogen peroxide, and electrolyte leakage which were also manifested by the increasing activities of enzymatic [superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)], and non-enzymatic antioxidants (phenolic, flavonoid, ascorbic acid, and anthocyanin content). B toxicity in the soil further increased the concentration of organic acids in the roots such as oxalic acid, malic acid, formic acid, citric acid, acetic acid, and fumaric acid. The addition of Si and fertilizer levels in the soil significantly alleviated B toxicity effects on S. oleracea by improving photosynthetic capacity and ultimately plant growth. The increased activity of antioxidant enzymes in Si and NPK-treated plants seems to play a role in capturing stress-induced reactive oxygen species, as was evident from the lower levels of oxidative stress indicators, organic acid exudation, and B concentration in the roots and shoots of Si and NPK-treated plants. Research findings, therefore, suggested that the Si and NPK application can ameliorate B toxicity in S. oleracea seedlings and result in improved plant growth and composition under metal stress as depicted by the balanced exudation of organic acids.

Thiourea-Capped Nanoapatites Amplify Osmotic Stress Tolerance in Zea mays L. by Conserving Photosynthetic Pigments, Osmolytes Biosynthesis and Antioxidant Biosystems.

Salinity is one of the most prevalent abiotic stresses which not only limits plant growth and yield, but also limits the quality of food products. This study was conducted on the surface functionalization of phosphorus-rich mineral apatite nanoparticles (ANPs), with thiourea as a source of nitrogen (TU-ANPs) and through a co-precipitation technique for inducing osmotic stress tolerance in Zea mays. The resulting thiourea-capped apatite nanostructure (TU-ANP) was characterized using complementary analytical techniques, such as EDX, SEM, XRD and IR spectroscopy. The pre-sowing of soaked seeds of Zea mays in 1.00 µg/mL, 5.00 µg/mL and 10 µg/mL of TU-ANPs yielded growth under 0 mM, 60 mM and 100 mM osmotic stress of NaCl. The results show that Ca and P salt acted as precursors for the synthesis of ANPs at an alkaline pH of 10-11. Thiourea as a source of nitrogen stabilized the ANPs' suspension medium, leading to the synthesis of TU-ANPs. XRD diffraction analysis validated the crystalline nature of TU-ANPs with lattice dimensions of 29 nm, calculated from FWHM using the Sherrer equation. SEM revealed spherical morphology with polydispersion in size distribution. EDS confirmed the presence of Ca and P at a characteristic KeV, whereas IR spectroscopy showed certain stretches of binding functional groups associated with TU-ANPs. Seed priming with TU-ANPs standardized germination indices (T50, MGT, GI and GP) which were significantly declined by NaCl-based osmotic stress. Maximum values for biochemical parameters, such as sugar (39.8 mg/g at 10 µg/mL), protein (139.8 mg/g at 10 µg/mL) and proline (74.1 mg/g at 10 µg/mL) were recorded at different applied doses of TU-ANP. Antioxidant biosystems in the form of EC 1.11.1.6 catalase (11.34 IU/g FW at 10 µg/mL), EC 1.11.1.11 APX (0.95 IU/G FW at 10 µg/mL), EC 1.15.1.1 SOD (1.42 IU/g FW at 5 µg/mL), EC 1.11.1.7 POD (0.43 IU/g FW at 5 µg/mL) were significantly restored under osmotic stress. Moreover, photosynthetic pigments, such as chlorophyll A (2.33 mg/g at 5 µg/mL), chlorophyll B (1.99 mg/g at 5 µg/mL) and carotenoids (2.52 mg/g at 10 µg/mL), were significantly amplified under osmotic stress via the application of TU-ANPs. Hence, the application of TU-ANPs restores the growth performance of plants subjected to induced osmotic stress.

Biodiesel Production Using Wild Apricot (Prunus aitchisonii) Seed Oil via Heterogeneous Catalysts.

We confined the formation and characterization of heterogenous nano-catalysts and then used them to produce biodiesel from the novel non-edible seed oil of Prunus aitchisonii. P. aitchisonii seeds' oil content was extracted at about 52.4 ± 3% with 0.77% FFA. Three different heterogenous nano-catalysts-calcined (CPC), KPC, and KOH-activated P. aitchisonii cake Titanium Dioxide (TiO2)-were synthesized using calcination and precipitation methods. The mentioned catalysts were characterized through XRD, SEM, and EDX to inspect their crystallin dimension, shape, and arrangement. Titanium dioxide has morphological dimensions so that the average particle size ranges from 49-60 nm. The result shows that the crystal structure of TiO2 is tetragonal (Anatase). The surface morphology of CPC illustrated that the roughness of the surface was increased after calcination, many macropores and hollow cavities appeared, and the external structure became very porous. These changes in morphology may increase the catalytic efficiency of CPC than non-calcined Prunus aitchisonii oil cake. The fuel belonging to PAOB stood according to the series suggested by ASTM criteria. All the characterization reports that P. aitchisonii is a novel and efficient potential source of biodiesel as a green energy source.