M. Motior Rahman

Purslane Weed (Portulaca oleracea): A Prospective Plant Source of Nutrition, Omega-3 Fatty Acid, and Antioxidant Attributes

Purslane (Portulaca oleracea L.) is an important plant naturally found as a weed in field crops and lawns. Purslane is widely distributed around the globe and is popular as a potherb in many areas of Europe, Asia, and the Mediterranean region. This plant possesses mucilaginous substances which are of medicinal importance. It is a rich source of potassium (494 mg/100 g) followed by magnesium (68 mg/100 g) and calcium (65 mg/100 g) and possesses the potential to be used as vegetable source of omega-3 fatty acid. It is very good source of alpha-linolenic acid (ALA) and gamma-linolenic acid (LNA, 18 : 3 w3) (4 mg/g fresh weight) of any green leafy vegetable. It contained the highest amount (22.2 mg and 130 mg per 100 g of fresh and dry weight, resp.) of alpha-tocopherol and ascorbic acid (26.6 mg and 506 mg per 100 g of fresh and dry weight, resp.). The oxalate content of purslane leaves was reported as 671–869 mg/100 g fresh weight. The antioxidant content and nutritional value of purslane are important for human consumption. It revealed tremendous nutritional potential and has indicated the potential use of this herb for the future.

Growth and nutrient uptake of maize plants as affected by elemental sulfur and nitrogen fertilizer in sandy calcareous soil

This study was carried out to investigate the effect of elemental sulfur (S 0 ) combined with or without N fertilizer on the growth and nutrient uptake such as nitrogen (N), phosphorus (P), sulfur (S), iron (Fe), zinc (Zn) and manganese (Mn) by maize plants grown in sandy calcareous soils. Elemental S at rates of 0, 1, 5 and 10 t ha -1 were tested combined with or without N fertilizer at rates of 0 and 0.34 t ha -1 in pots using normal irrigation water (pH >7.5) under Al Zaid and Al Semaih soils in evaporative cooled greenhouse conditions. Electrical conductivity (EC) increased (2.50 to 2.95 dSm -1 ) significantly and decreased (5.07 to 6.06 dSm -1 ) with application of S 0 at rates of 5 and 10 t ha -1 combined with N fertilizer in both Al Zaid and Al Semaih soils, respectively. Soil acidity improved by decreasing soil pH (1.41 to1.52 unit) with application of S 0 at the rate of 10 t ha -1 combined with N fertilizer. Addition of S 0 at the rate of 5 t ha -1 combined with N fertilizer recorded superior total dry matter (TDM) and maximum uptake of all nutrients in both soils. Total dry matter accumulation and nutrient uptake had positive correlation, while soil pH showed negative correlation with TDM and uptake of all nutrients. Based on experimental findings, S 0 at the rate of 5 t ha -1 combined with N fertilizer is suitable for growth of maize in both soils. Collectively, the results indicate that Al Zaid soil is more favorable due to higher nutrient uptake and growth of maize than Al Semaih soil. Key words : Elemental sulfur, nutrient uptake, maize, sandy calcareous soil.

The Influence of 1-Triacontanol on the Growth, Flowering, and Quality of Potted Bougainvillea Plants (Bougainvillea glabra var. “Elizabeth Angus”) under Natural Conditions

Selected physiological and biochemical parameters were monitored at the vegetative and reproductive growth stages in potted Bougainvillea plants treated with five different concentrations of TRIA. Advanced flowering, flower bud number, and blooming rate increased significantly with 0.5 and 1.0 mg/L TRIA treatments. Similarly, photosynthetic rate, pigment content, quantum yield, and stomatal conductance increased significantly with 2.5, 1.0, and 5.0 mg/L TRIA treatments. Higher levels of N, P, and K, as well as increased total soluble solids (TSS) and higher sugar and protein contents, were recorded in treated plants. Furthermore, 46% more flowers, a 1.5-fold increase in bract weight, increased longevity, and 40% less leaf abscission were recorded following 2.5 mg/L TRIA treatment. Phenol and flavonoid contents, sucrose phosphate synthase (SPS), and antioxidant activities were also markedly increased with 2.5 and 1.0 mg/L TRIA treatments. However, ethylene production was significantly lower in the treated plants. Positive correlations were observed between leaf TSS and flowering time and flower number, between leaf sugar content and bract weight, and between net photosynthesis and bract growth and dry matter production. It can be concluded that the foliar spray of TRIA stimulates growth, enhances flowering, and improves the quality of potted Bougainvillea plants.

Fruit development, pigmentation and biochemical properties of wax apple as affected by localized Application of GA3 under field conditions

ABSTRACT This study investigated the effects of gibberellin (GA 3 ) on the fruit development, pigmentation and biochemical properties of wax apple. The wax apple trees were rubbing treated with 0, 20, 50 and 100 mgGA 3 /l under field conditions. The localized application (rubbing) of 50 mg GA 3 /l significantly increased the fruit set, fruit length and diameter, color development, weight and yield compared to the control. In addition, GA 3 treatments significantly reduced the fruit drop. With regard to the fruit quality, 50 mg/l GA 3 treatment increased the juice content, K + , TSS, total sugar and sugar acid ratio of wax apple fruits. In addition, higher vitamin C, phenol, flavonoid, anthocyanin, carotene content, PAL and antioxidant activities were recorded in the treated fruits. There was a positive correlation between the peel colour and TSS content and between the PAL activity and anthocyanin formation in the GA 3 -treated fruit. It was concluded that rubbing with 50 mg/L GA

Tropical Legume Crop Rotation and Nitrogen Fertilizer Effects on Agronomic and Nitrogen Efficiency of Rice

Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m−2 preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m−2. No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m−2 achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13–23% higher grain yield than rice after fallow rotation with 8 g N m−2. The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m−2 can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m−2. The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.

Characterization and identification of soft rot bacterial pathogens in Bangladeshi Potatoes

We reported the characterization and identification of pathogenic bacterial strains causing soft rot in potato tuber in Bangladesh under storage conditions. Identification of bacterial pathogens in tuber is important to take appropriate disease control measures and to develope resistant plants through classical breeding or genetic engineering. A total of 92 bacterial strains were extracted from the soft rotted potato and 26 of them were found to produce soft rot on potato slices under control environment. Out of 26 soft rot causing bacterial strains, 12 were found to be aggressively virulent and were selected for characterization and identification by physiological and biochemical testing schemes. Out of the 12 virulent strains, 8 isolates designated as P-01, P-04, P-11, P-48, P-111, P-134, P-138, and P-169 were identified as Erwinia subsp. carotovora and 4 isolates labeled as P-28, P-128, P-142, and P-179 were identified as Erwinia chrysanthemi.

Nanostructured Materials: Bioengineering Platforms for Sensing Nucleic Acids

Detection of specific nucleic acid targets is of enormous and increasing interest in molecular biodiagnostics, food analysis, forensic investigation, and environmental monitoring. The advancement of nanotechnology with a myriad of novel and engineered nanomaterials and their hybrids with attractive physiochemical properties has raised hopes for the development of DNA sensors capable of identifying specific nucleic acid sequences with single molecule precision, avoiding the need of skilled personnel or sophisticated machineries. Compared to the traditional sensing platforms, DNA–nanomaterial hybrids provide better sensitivity and multiplexing facility, reducing analysis cost and increasing detection precision by several orders of magnitudes. The biofusion of DNA with nanostructured gold, nanostructured silica, nanogap semiconductors, carbon nanotubes, graphenes, and quantum dots has shown great possibilities to fabricate specialized nanostructured configurations capable of enhancing DNA detection several-fold. Miniaturized devices with embedded DNA of thousands of fingerprints in lab-on-a-chip are no longer a surprise. Here, we describe potential candidate nanomaterials and their molecular binding patterns with DNA to constitute a sensing platform for nucleic acid targets. The future perspectives and challenges of nanotechnology strategies are also outlined.

Identification of resistant biotypes of Leptochloa chinensis in rice field and their control with herbicides

Weed populations of sprangletop ( Leptochloa chinensis ) such as Kampung Permetang (KP), Kampung Pida-Tiga (KPT), Sungai Baru (SB1 and SB2), Kampung Pida-Empat (KPE), Singkir Yan (SY), Tanjung Dawai (TD), Dulang Besar (DB) and Kampung Bahagia (KB1 and KB2) were collected from paddy (Oryza sp.) growing areas in Kedah, Malaysia to identify resistant biotypes and their method of control. Weed biotypes were evaluated against all varying rates of propanil, quinclorac and cyhalofop-butyl. Except SY, all weed populations showed resistance against propanil at the rate of 5500 ml a.i. ha -1 , on the contrary all weed populations appeared as susceptible against higher rates of propanil (11000 ml a.i. ha -1 ) except SB2 and KB1. All populations except KP and SB1 were resistant against cyhalofopbutyl at rates of 800 and 1600 ml a.i. ha -1 . Kampung Bahagia (KB2) against cyhalofop-butyl at rates of 800 and 1600 ml a.i. ha -1 appeared as resistant and susceptible, respectively. Resistant biotypes were two times strongly resistant to propanil while one time strongly resistant to cyhalofop-butyl, respectively, than susceptible biotypes. Regardless of rates, quinclorac was ineffective against any of the biotypes. Resistant biotype SB2 was controlled by combined application of propanil and cyhalofopbutyl at rates of 5500 and 800 ml a.i. ha -1

Phyto-evaluation of Cd-Pb Using Tropical Plants in Soil-Leachate Conditions

Sources of soil contamination can exist in various types of conditions including in the form of semifluids. In this study, 3 different types of tropical plants, Acacia (Acacia mangium Willd), Mucuna (Mucuna bracteata DC. ex Kurz) and Vetiver (Vetiveria zizanioides L. Nash), were tested under different levels of soil-leachate conditions. The relative growth rate, metal tolerance, and phytoassessment of cadmium (Cd) and lead (Pb) accumulation in the roots and shoots were determined using flame atomic absorption spectrometry. Tolerance index, translocation factor, metal accumulation ratio, and percentage metal efficacy were applied to assess the metal translocation ability among all the 3 types of plants. Significantly higher (P < .05) accumulation of Cd and Pb was exhibited in the roots and shoots of all 3 plants growing under the soil-leachate conditions. However, negative growth performance and plant withering were observed in both Acacia and Mucuna with increased application of higher soil-leachate levels. Vetiver accumulated remarkably higher total concentration of Cd (116.16-141.51 mg/kg) and Pb (156.37-365.27 mg/kg) compared with both Acacia and Mucuna. The overall accumulation trend of Cd and Pb in the 3 plants growing under the soil-leachate conditions was in the order of Vetiver > Acacia > Mucuna. The findings of the study suggest that Vetiver has great potential as Cd and Pb phytoremediator in soil-leachate conditions.