Determination of the optimal conditions for mutagenesis induction in a commercial Arabica coffee variety.

2021 ◽  
pp. 326-337
Author(s):  
Andrés Gatica-Arias ◽  
Jorge Rodríguez-Matamoros ◽  
Ana Abdelnour-Esquivel ◽  
Marta Valdez-Melara

Abstract Low genetic diversity and autogamous reproduction limit genetic improvement of Coffea arabica L. As a consequence, susceptibility to biotic and abiotic stresses increases. Induced mutagenesis is an alternative strategy for increasing genetic variability and for the development of varieties tolerant or resistant to biotic and abiotic factors. In the present study, the effect of three mutagenic agents (NaN3, EMS and 60Co gamma-rays) on survival of Arabica coffee zygotic embryos was evaluated. The zygotic embryos were immersed for 10 min in a solution of NaN3 (0, 2.5, 5.0, 7.5, 10.0, 12.5, 15.0 and 20.0 mM) or for 2 h in a solution of EMS (0, 0.5, 1, 1.5, 2, 4 and 6% v/v) or irradiated with 0, 20, 40, 60, 80 or 100 Gy. As the concentration or dose of the applied mutagen increased, survival decreased. The LD50 values for sodium azide, EMS and 60Co were 12.5 mM (51.6%), 1% v/v (48.3%) and 40 Gy (50.0%), respectively. Our results indicated that coffee zygotic embryos are suitable for chemical and physical mutagenesis and this offers an alternative for the genetic improvement of agriculturally important traits in coffee.

2020 ◽  

The banana agro-export sector in Ecuador provides millions of dollars in income for this concept, but with this development, a series of quality standards have been established that must be met to enter the export system. This has contributed to establishing good post-harvest production and management practices that guarantee the optimal production of bananas and plantains. The objective of this study was to determine the factors involved in the rejection of bananas (Musa acuminata) destined for international commercialization. The methodology considered the design modality of non-experimental transactional research, with a quantitative approach. The methodological design was developed in three phases at Finca 6 Hermanas located in the Barraganete sector of the San Juan parish in the Puebloviejo canton of the Los Ríos Province, Ecuador. The results highlight that the main causes for which banana rejection is generated are due to abiotic factors (damage, dry latex, scar, insect damage, broken neck, overgrowth) in a higher percentage of 79.55 % and biotic factors ( twins, diseases, short finger) by 20.45 %. The average rejection was 6 361 fingers and1 269 Kilograms (K) over the 6-week study duration. The analysis of variance turned out to be significant for variable 1 (biotic and abiotic). Ho is rejected; with the criterion of p-value < 0.0001 and F (9; 45) = 2.10., F = 13.17> F critic. In the case of variable (2) “work weeks”, Ho is accepted with the criteria obtained of p-value of 0.7694 and F (5; 45) = 2.4., As F = 0.51 < F critic, it is concludes, that with a significance level of 5% the null hypothesis is accepted. It is concluded that these figures lead to the elaboration of strategies that systemically mitigate the damages, by correcting each one of the causes that cause the deterioration of the banana and increasing the economic gains of the commercialization process.


1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).


1982 ◽  
Vol 47 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Irena Němcová ◽  
Pavla Plocková ◽  
Tran Hong Con

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.


1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.


2019 ◽  
Vol 298 ◽  
pp. 89-93 ◽  
Author(s):  
Thien Hien Tran ◽  
Thi To Quyen Ngo ◽  
Thi Kim Ngan Tran ◽  
Tri Duc Lam ◽  
Tan Phat Dao ◽  
...  

Vietnam is the world's leading country in growing and producing pepper trees. In this study, we attempted the optimization of white pepper essential oil extraction. The obtained oil was then subject to determination of constituent composition via GC-MS method. The essential oil performance achieved 3.6% by hydro-distillation process with optimal conditions (25 grams of fresh pepper, size 18, 120 minutes extraction, 130°C). A total of 23 volatile constituents were identified from the white pepper essential oil, with the major components being 27.4% of Limonene, 3-Carene 22,928%, Sabinene 17,622%, β-pinene 10.068%, α-Pinene 5.426%.


Author(s):  
C. Montagnon ◽  
A. Mahyoub ◽  
W. Solano ◽  
F. Sheibani

AbstractWhilst it is established that almost all cultivated coffee (Coffea arabica L.) varieties originated in Yemen after some coffee seeds were introduced into Yemen from neighboring Ethiopia, the actual coffee genetic diversity in Yemen and its significance to the coffee world had never been explored. We observed five genetic clusters. The first cluster, which we named the Ethiopian-Only (EO) cluster, was made up exclusively of the Ethiopian accessions. This cluster was clearly separated from the Yemen and cultivated varieties clusters, hence confirming the genetic distance between wild Ethiopian accessions and coffee cultivated varieties around the world. The second cluster, which we named the SL-17 cluster, was a small cluster of cultivated worldwide varieties and included no Yemen samples. Two other clusters were made up of worldwide varieties and Yemen samples. We named these the Yemen Typica-Bourbon cluster and the Yemen SL-34 cluster. Finally, we observed one cluster that was unique to Yemen and was not related to any known cultivated varieties and not even to any known Ethiopian accession: we name this cluster the New-Yemen cluster. We discuss the consequences of these findings and their potential to pave the way for further comprehensive genetic improvement projects for the identification of major resilience/adaptation and cup quality genes that have been shaped through the domestication process of C. arabica.


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ricardo Jorge Oliveira ◽  
Bruna Santos ◽  
Maria J. Mota ◽  
Susana R. Pereira ◽  
Pedro C. Branco ◽  
...  

Abstract Lignocellulosic biomass represents a suitable feedstock for production of biofuels and bioproducts. Its chemical composition depends on many aspects (e.g. plant source, pre-processing) and it has impact on productivity of industrial bioprocesses. Numerous methodologies can be applied for biomass characterisation, with acid hydrolysis being a particularly relevant step. This study intended to assess the most suitable procedures for acid hydrolysis, taking Eucalyptus globulus bark as a case study. For that purpose, variation of temperature (90–120 °C) was evaluated over time (0–5 h), through monosaccharides and oligosaccharides contents and degradation. For glucose, the optimal conditions were 100 °C for 2.5 h, reaching a content of 48.6 wt.%. For xylose, the highest content (15.2 wt.%) was achieved at 90 °C for 2 h, or 120 °C for 0.5 h. Maximum concentrations of mannose and galactose (1.0 and 1.7 wt.%, respectively) were achieved at 90 and 100 °C (2–3.5 h) or at 120 °C (0.5–1 h). These results revealed that different hydrolysis conditions should be applied for different sugars. Using this approach, total sugar quantification in eucalyptus bark was increased by 4.3%, which would represent a 5% increase in the ethanol volume produced, considering a hypothetical bioethanol production yield. This reflects the importance of feedstock characterization on determination of economic viability of industrial processes.


2021 ◽  
Vol 69 (7) ◽  
pp. 2253-2261
Author(s):  
Caitlin N. Cain ◽  
Noah J. Haughn ◽  
Hayley J. Purcell ◽  
Luke C. Marney ◽  
Robert E. Synovec ◽  
...  

2008 ◽  
Vol 3 ◽  
pp. ACI.S939 ◽  
Author(s):  
J. Rodríguez Flores ◽  
A.M. Contento Salcedo ◽  
L. Muñoz Fernández

Micellar electrokinetic chromatography (MEKC) was investigated for the simultaneous determination of letrozole, imipramine and their metabolites in human urine samples over a concentration range of therapeutic interest. Experimental parameters such as pH of the running electrolyte, sodium dodecylsulphate (SDS) concentration, borate concentration, voltage, etc were investigated. Under optimal conditions of 25 mM SDS, 15 mM borate buffer (pH 9.2), 15% 2-propanol, as background electrolyte; 28 kV and 40 °C, as voltage and cartridge temperature, respectively; resolution between the peaks was greater than 1.7. Before the determination, a solid phase extraction (SPE) procedure with a C18 cartridge was optimized. Good linearity, accuracy, precision, robustness and ruggedness were achieved and detection limits of 12.5 ng/mL for letrozole and its metabolite and 37.5 ng/mL, were obtained for imipramine and their metabolites. Real determinations of these analytes in two patient urines were carried out. Sensitivity achieved in this method is sufficient to perform kinetic studies in humans.


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