In Vitro Propagation of Eggplant through Meristem Culture

Meristem culture was done for developing an efficient protocol of production of eggplant clones. Shoot tips of 30-35 days old field grown eggplants were used for meristem isolation. Three cultivars viz. ‘Islampuri’, ‘Khatkhatia’ and ‘Katabegun’ were used in the present investigation as explants source. Surface sterilization of shoot tips was found to be the best in 0.1% HgCl2 solution for 3 minutes. For primary establishment of isolated apical meristem in MS liquid medium containing 2.0 mg l-1 BAP was found the best in cv Islampuri. BAP was also proved to be best for the primary establishment of isolated apical meristem in all the cultivars. Subsequent development of meristem derived shoot was achieved in MS semisolid medium containing either 2.0 mg l-1 BAP and 1.0 mg l-1 NAA or 1.0 mg l-1 BAP. For root development from meristem derived shoots, 1.0 mg l-1 IBA was found most responsive in cv. ‘Islampuri’ and ‘Khatkhatia’. Aft er transplantation, the in vitro plants showed normal growth

Antifungal Activity of Fruit Extracts of Different Water Chestnut Varieties

The antifungal activity of three varieties (red, green and wild) of water chestnut fruit extracts was studied against a number of fungal species. A strong antifungal activity of ethanol and petroleum extract was found against the treated fungi resulting remarkable inhibition zone in comparison to both Dithane-M45 fungicide and control. It has also been evident that wild variety of water chestnut was comparatively more efficient in respect to antifungal activity compared to the red and green variety of the same plant

Genotypic screening of wheat and their physiological responses under lead toxicity

Lead (Pb) is the second most harmful heavy metal contaminant in the environment and toxic for plant growth and development. Therefore, the identification and selection of plant genotypes tolerant to Pb stress are of great significance. In this study, twenty-six wheat lines (Triticum aestivum) were screened for Pb tolerance based on their morpho-physiological variations at the seedling stage with a rapid hydroponic technique using lead nitrate (Pb(NO3)2) at two concentrations (500 ?M and 1 mM) along with control. Wheat genotypes showed distinct variations in plant height, plant biomass and chlorophyll concentration in response to different concentrations of Pb. Considering all parameters, Akbar was found most tolerant (T) with minimum RS (2.97) to Pb stress, followed by BARI Gom-31 (3.45), Barkat (3.54) and Sufi (3.65), while BARI Gom-26 (10.14) was most sensitive (S) followed by Khude Gom (9.69), BARI Gom-30 (8.79), LalGom (8.76) and BARI Gom-32 respectively. More scores were seen in the remaining genotypes and were graded as moderately tolerant/resistant (MT) to Pb stress. Results showed that the resistant line had less damage to root and shoot characteristics along with chlorophyll score, thereby providing a hint about the Pb tolerance capacity of wheat genotypes at the seedling stage. Furthermore, findings indicate that Pb susceptibility in wheat is predominantly associated with a decrease in the Pb components of the root and shoot. We suggest Akbar as an elite genotype to cultivate or use in downstream studies on the basis of our findings to ensure an improved crop production relative to other varieties evaluated. These findings provide the necessary background for Pb cleansing and Pb-free wheat development for environment and health safety

Detection of Quorum Sensing Signals in Gram-Negative Bacteria by Using Reporter Strain CV026

Quorum sensing signals are referred to as acylated homoserine lactones (AHL) that are mainly found in Gram-negative bacteria. It implies the ability of certain bacteria of producing different AHL molecules. The bacteria Pseudomonas aureofaciens and Xenorhabdus nematophila were cultured in Luria-Bertani (LB10) media and CV026 was used as a reporter strain to detect the presence of AHLs produced by the cultured bacteria. In this study, the reporter strain has revealed the quorum sensing ability of P. aureofaciens and X. nematophila by producing the purple pigment violacein in the supply of external AHLs molecules. Thin layer chromatography (TLC) bioassay having four controls was conducted to detect specific AHL molecule supplied by P. aureofaciens and X. nematophila. The specific AHL molecule was observed to be migrated according to their polarity on the TLC plate

Detection of Quorum Sensing Signals in Gram-Negative Bacteria by Using Reporter Strain CV026

Quorum sensing signals are referred to as acylated homoserine lactones (AHL) that are mainly found in Gram-negative bacteria. It implies the ability of certain bacteria of producing different AHL molecules. The bacteria Pseudomonas aureofaciens and Xenorhabdus nematophila were cultured in Luria-Bertani (LB10) media and CV026 was used as a reporter strain to detect the presence of AHLs produced by the cultured bacteria. In this study, the reporter strain has revealed the quorum sensing ability of P. aureofaciens and X. nematophila by producing the purple pigment violacein in the supply of external AHLs molecules. Thin layer chromatography (TLC) bioassay having four controls was conducted to detect specific AHL molecule supplied by P. aureofaciens and X. nematophila. The specific AHL molecule was observed to be migrated according to their polarity on the TLC plate

Screening of Fe-Deficiency Tolerance in Okra (<i>Abelmoschus esculentus</i> L.) Through Hydroponic Culture

Screening for Fe deficiency tolerance in okra (Abelmoschus esculentus) Bangladeshi genotypes (‘BARI-1’, ‘Local variety’, ‘Orca Onamica’, and ‘Prince’) were studied based on different morphological and physiological parameters. Number of leaves, shoot height and weight were significantly reduced in ‘Orca Onamica’ and ‘Prince’, whereas ‘BARI-1’ and ‘Local variety’ did not show prominent decrease in the aforesaid growth parameters under Fe deficiency. Again, ‘Orca Onamica’ and ‘Prince’ showed significantly decreased root length and root biomass under Fe deficiency. In contrast, these parameters were unchangeable in ‘BARI’-1 and ‘Local variety’ in Fe shortage compared to controls. Furthermore, Fe deficiency caused severe decrease in chlorophyll (a and b) and Fe concentrations in leaves of ‘Orca Onamica’ and ‘Prince’ grown on hydroponic culture. In contrast, chlorophyll (a and b) and Fe concentrations were not significantly decreased in ‘BARI-1’ and ‘Local variety’ due to Fe deficiency. Based on these findings, tolerance to Fe deficiency in these okra cultivars can be categorized as: tolerant (‘BARI-1’ and ‘Local’), and sensitive (‘Orca Onamica’ and ‘Prince’). The ranking can be applied in plant breeding program and may have great advantage over conventional methods. This study also demonstrates the effectiveness of hydroponic culture as an efficient method to screen Fe-efficient crop plants

Biochemical and molecular mechanisms associated with Zn deficiency tolerance and signaling in rice (Oryza sativa L.)

In this study, zinc (Zn) deficiency caused a significant reduction in growth parameters and tissue Zn concentrations in BRRI 33 (sensitive) but not in Pokkali (tolerant). The increase of proton extrusion in both genotypes under high pH suggests that it gets triggered as a common consequence of reducing pH and solubilization of Zn. Real-time PCR showed pronounced upregulation of OsZIP4, OsDMAS1, OsNAS2 and OsPCS1 in Zn-deficient roots of Pokkali, and to a lesser extent in BRRI 33 only for OsZIP4 and OsPCS1. This suggests that OsDMAS1, OsNAS2 and OsPCS1 functions as secondary consequences leading to higher chelation and uptake of Zn under Zn deficiency in Pokkali. Further, a major increase in CAT, POD, SOD, GR and key metabolites suggests that high antioxidant defense plays a critical role in Zn deficiency tolerance in Pokkali. Further, Pokkali self-grafts and plants having Pokkali rootstock combined with BRRI 33 scion showed no significant decline in plant height, root dry matter and Zn concentration along with upregulation of Zn transporters (OsZIP4 and OsIRT1) under Zn deficiency, suggesting that signal driving mechanisms for Zn deficiency tolerance mechanisms are generated in the root and Zn-inefficient BRRI 33 is not capable of producing signals or sensing them