Impact of Encapsulation on Plantlet Regeneration from in vitro Grown Shoot tips of Citrus aurantifolia (Lime)

In order to conserve diverse species of citrus, an experiment on in vitro micropropagation and production of synthetic seeds from in vitro regenerated plant propagules of the species; Citrus aurantifolia (Lime) was carried out in which shoot tips were found to be suitable for excapsulation of artificial seeds. Highest rate of germination was obtained from the shoot tips when MS was supplemented with 1 mg/l BAP. Beaded shoot tips produced maximum germination (81.43%). Germinated synthetic seeds with well established roots and shoots were were taken out from the culture bottles and transferred in plastic cups containing a mixture of sterile soil: sand and farmyard manure at a ratio of 1:1:1. Seedlings were further shifted in earthen pots and kept in a partial shed net house for 7 days. Those seedlings were finally transferred under the field conditions for acclimatization. Plant Tissue Cult. & Biotech. 31(1): 43-49, 2021 (June)

In vitro Callus Induction and Regeneration of Popular Indica Rice Genotypes

Five rice cultivars viz., ASD 16, White Ponni, Pusa Basmati 1, Pusa Sugandh 4 and Pusa Sugandh 5 belonging to subspecies indica were compared for its ability in callus formation and regeneration. In this experiment, the different parameters viz., the effect of hormones (2,4-D and kinetin), organic supplement (coconut milk O1-CM 100 mll-1, O2-CM 75 mll-1, O3-CM 50 mll-1), explants (seed and immature embryo), media (MS and N6), carbon source (sucrose and maltose) using five genotypes on callus response was studied. The effect of hardening methods was also assessed. Results showed that for enhanced callus induction was with MS medium supplemented with 2.0 mgl-1 2, 4-D + 0.5 mgl-1 kinetin + 30 gl-1 maltose irrespective of explants used. Addition of 100 ml l-1 coconut milk was found have improvement in callus response. The performance of immature embryo was better than seed for callus induction, emrbyogenic callus formation, rhizogenic callus formation and regeneration. MS media provided superiority over N6. Among the genotypes Pusa Basmati 1 rendered outstanding performance in callus behavior. The treatment combination MS + 2.5 mgl-1 BAP + 0.5 mgl-1 NAA + 1.0 mgl-1 KN gave the highest organogenesis response and regeneration of plantlets. Hardening in mist chamber was recognized as the best method to give the highest per cent of regenerated plant lets.

The regeneration of Acer rubrum L. "October Glory" through embryonic callus

Background Landscape industry has been recognized as the "eternal sunrise industry", however, the introduction and cultivation of colored-leaf trees in southern China is relatively vacant.Results The results showed that the induction effect of the stem was the best for the embryogenic callus, and the regenerated plant with genetic stability was obtained. The MS (Murashige&Skoog) +0.8 mg/L TDZ (Thidiazuron) +1.0 mg/L 6-BA (6-Benzylaminopurine) +0.5 mg/L NAA (1-naphthlcetic acid) +35 g/L sucrose+7.5 g/L semi-fixed medium was the best for callus formation. When selecting type VI callus as embryonic callus induction material, MS+0.6 mg/L TDZ+0.5 mg/L 6-BA +2.0 mg/L IAA (Indole-3-acetic acid) +35 g/L sucrose+7.5 g/L semi-fixed medium can get embryonic callus. The optimal medium for adventitious bud induction is MS+1.0 mg/L TDZ+3.0 mg/L 6-BA+0.2 mg/L NAA+1.2 mg/L IAA+35 g/L sucrose+7.5 g/L semi-fixed medium.The induction rate of adventitious roots in MS+0.6 mg/L TDZ+1.0 mg/L 6-BA+3 mg/L NAA+35 g/L sucrose+7.5 g/L semi-fixed medium was the highest, reaching 76%.Conclusion In the course of our research, we found that PGRs play an important role in the callus induction stage, and the effect of TDZ is particularly obvious; The callus cells grow and proliferate according to the "S" growth curve, and can be subcultured when the highest growth point is reached to maintain the rapid proliferation of the callus cells and to avoid inactivation of callus caused by tight niche.

Functional Characterization of9-/13-LOXsin Rice and Silencing Their Expressions to Improve Grain Qualities

Lipoxygenases (LOXs) are involved in oxidative rancidity and render rice unsuitable for human consumption. Here, RNA interference- (RNAi-) induced gene expression inhibition was used to analyze the functions of the bran/seed-specific LOXs in rice.r9-LOX1andL-2(9-LOX category) were the candidate genes expressing a bran/seed-specific LOX, whileRCI-1was (13-LOX category) a plastid-specific LOX. Real-time PCR showed that three LOXs were cultivar/tissue specific expression on a certain level.r9-LOX1andL-2were generally much higher in active bran/seed than in stabilized bran, mature seed, and regenerated plant.RCI-1was barely expressed in seed. In transgenic lines,r9-LOX1, as well asL-2, expression was dramatically downregulated, compared to the nontransgenic controls. SPME/GC-MS analysis ofr9-LOX1RNAi transgenic lines showed 74.33% decrease in nonanal content (formed during oxidation of linoleic acid by lipoxygenase), but 388.24% increase in acetic acid and 184.84% hexanal (direct products of 13-LOX). These results indicate thatr9-LOX1positively regulates the amount of nonanal but negatively regulates acetic acid and hexanal. The negative regulation may be due to a mechanism of negative feedback between LOX family members. The information will help comprehensively understand the function of the bran/seed-specific LOXs,r9-LOX1, and improve the storage quality in the future.

Improving Lifetime and Manufacturability of an RQL Combustor for Microturbines: Design and Numerical Validation

A new annular RQL combustion chamber of an 80 kWel Elliott TA80R micro gas turbine was designed and built with a modified geometry to overcome known failures at low running hours (around 2500 hrs) caused by overheating. Design considered simplified manufacturability and flow optimization to reduce emission while maintaining similar temperatures and efficiencies. A preliminary geometry was analyzed and also built to verify manufacturability and economics. It was easily built with overall brute costs around 3000 €. It has also run continuously for over 27.000 hrs. An optimized geometry, however, guaranteed similar TIT with respect to the original geometry with a considerable reduction in CO and NOx emissions. Given the installation of the mGT at the IRP (Integrated Pyrolysis Regenerated Plant) the modified geometry was tested through CFD analysis on syngas from biomass thermochemical processes. The results show that further modifications of the liner are required for optimal operation and to reach adequate values for Turbine Inlet Temperature.

Antimicrobial peptides expressed in wheat reduce susceptibility to Fusarium head blight and powdery mildew

Badea, A., Eudes, F., Laroche, A., Graf, R., Doshi, K., Amundsen, E., Nilsson, D. and Puchalski, B. 2013. Antimicrobial peptides expressed in wheat reduce susceptibility to Fusarium head blight and powdery mildew. Can. J. Plant Sci. 93: 199–208. Antimicrobial peptides (AMPs) have a broad spectrum of action against bacteria, fungi and viruses, which makes them attractive for building plant defense against a diversity of pathogens. Peptides MsrA2 and 10R were cloned in three genetic constructs for tissue-specific expressions in wheat, using either Lem1, GstA1WIR1a, or Ltp6 and LTP6 signal peptide targeting the lemma/palea, leaves and spikes, epicarp and endomembrane system, respectively. The minimal cassettes for these three genetic constructs and for Pat marker construct were co-delivered in immature wheat scutella using biolistics, and green plantlets were regenerated in presence of 5 mg L−1 glufosinate. Molecular screening confirmed one regenerated plant carried and expressed all transgenes (AMP+): one copy of 10R driven by Ltp6 promoter, one copy of msrA2 driven by GstA1Wir1a and two copies of msrA2 driven by Lem1. Its offspring and T3 generation were challenged with Fusarium graminearum and Blumeria graminis in a contained environment. A reduction of 50% in Fusarium head blight susceptibility was observed in T1, and was inherited through T3 generation. The latter, also presented a 53% reduction in Fusarium damaged kernels and 62% reduction in deoxynivalenol accumulation compared with wild cv. Fielder and sister lines AMP−. MsrA2 and 10R producing T3 lines showed an average significant reduction of 59% in powdery mildew susceptibility compared with cv. Fielder. Synthetic MsrA2 and 10R peptides were effective as in vivo antifungal peptides in wheat. The expression of antimicrobial peptides in plant cells or tissues may have great potential to limit pathogen infection or growth protecting wheat against a diversity of fungal diseases.

Experimental and CFD Evaluation of the Part Load Performance of a Micro Gas Turbine Fuelled With CH4-N2 Mixtures

There is a strong interest in numerical and experimental research on syngas combustion in GTs however experimental studies require syngas generation which is costly and also provides a variable and dirty fuel gas. To investigate the combustion behaviour and GT performance when fuelled with low LHV syngas, nitrogen diluted natural gas can be considered. To this aim the micro gas turbine (mGT) available at the IPRP (Integrated Pyrolysis Regenerated Plant) pilot facility of the University of Perugia, modified to use biomass pyrolysis gas, was fuelled with a CH4−N2 mixtures at different part load conditions obtained from pipeline (CH4) and cylinders (N2). The aim of the work is to analyze the functioning condition of the mGT which is monitored by a dedicated data acquisition system. Performances are evaluated and discussed showing that nitrogen dilution does not affect significantly efficiency and NOx production while CO emission increase slightly when increasing nitrogen content and this is more evident when decreasing the load. A CFD model of the combustion chamber, which was developed and tuned in previous works by the authors, was also run to reproduce experimental data showing a good agreement and also suggesting flame detachment in the mixing tube when nitrogen is present.