Examinando por Materia "Drought"

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Comparing the differential expression of selected genes in native Peruvian potatoes in response to early and late drought conditions
(Palm Beach State College, 2017-04-01) Cornelio, Laynet; Perez, Indira; Vazquez, Carlos; Martinez, Diana; Ponce, Olga Patricia; Murata, Emi; Torres, Yerisf; Zuñiga López, Luz Noemí; Orjeda, Gisella; Maul, Dora Pilar; Merino, Carlos
Plant response to drought stress comprises growth inhibition, stomatal closure, an increase in abscisic acid (ABA) biosynthesis and increased antioxidant metabolism, among others. Drought tolerance in plants is linked to photosynthesis and carbohydrate metabolism. Drought-inducible functional proteins include those that protect cells from water deficit and oxidation as well as transcription factors and signaling molecules associated with the water-stress response. Native potatoes from the Andean regions of Peru, Ecuador and Bolivia grow at altitudes as high as 11483 ft. (3500m) above sea level. Because of their high genetic diversity, they are well adapted to the harsh environmental conditions that prevail in the high Andes, including drought. This makes them ideal candidates for gene expression studies associated with drought tolerance. St. Thomas University is collaborating with the Universidad Peruana Cayetano Heredia (UPCH, Lima, Peru), and the Instituto Nacional de Innovacion Agraria (INIA, Huancayo, Peru) in a gene expression study in native potatoes associated with early and late drought responses. Selected drought associated candidate genes from RNA-seq analysis were used in primer design and quantitative RT-PCR analysis. Differential gene expression in tolerant vs. susceptible cultivars has been confirmed for two heat shock proteins, a dehydration-response element binding protein and for a major pollen allergen.
Morpho-Physiological response of four native accessions of Phaseolus vulgaris L. subjected to water stress under greenhouse conditions in northeastern Peru
(MDPI, 2024-09-06) Santillan Huaman, Anlly; Tejada Alvarado, José Jesús; García, Ligia; Vásquez García, Jheiner; Fernandez Huaytalla, Elizabeth; Vilca Valqui, Nuri Carito; Oliva Cruz, Manuel
Phaseolus vulgaris L. is a legume of high nutraceutical value, widely cultivated and consumed. However, common bean production faces challenges such as water stress that severely affects its growth and yield. This study evaluated the morphological and physiological response of four native P. vulgaris accessions subjected to different irrigation treatments under greenhouse conditions. A completely randomized design with factorial arrangement was used, evaluating three irrigation frequencies (100%, 50%, 25%) in combination with four accessions (PER1003541, PER1003542, PER1003543, PER1003544). The results showed that with the 25% irrigation treatment, PER1003544 showed a 54.62% decrease in leaf area, while PER1003542 and PER1003543 experienced reductions of 56.56% and 59.24%, respectively. In addition, accession PER1003544 reported a smaller reduction in the number of flowers and pods, with decreases of 40.21% and 29.9%, in contrast to PER1003543, which showed decreases of 60.66% and 52.63%, respectively. Accessions PER1003541 and PER1003544 also recorded the lowest reductions in dry biomass, with 31.85%and 35.41%, respectively. Regarding yield, PER1003544 and PER1003541 experienced reductions of 59.01% and 69.79%, respectively, unlike PER1003543, which showed a 90% decrease. In relation to stomatal density, PER1003541 recorded a reduction of 28.28%, while PER1003544 had a decrease of 37.10%, and PER1003543 experienced a reduction of 47.05%; chlorophyll content showed a similar trend. Finally, PER1003544 maintained a relatively stable stomatal index, with a reduction of 29.01%, compared to PER1003543, which reduced by 60.99%. In conclusion, accession PER1003544 stands out as a promising variety for breeding programs focused on water stress tolerance, contributing to food security and agricultural sustainability in areas affected by limited water availability. However, PER1003541 would be a suitable additional option, offering farmers flexibility in their crop selection according to the specific conditions of their environment.
Rye production under acid soils and drought conditions: an alternative for the sustainability of high Andean livestock farming in Peru
(MDPI, 2023-07-05) Carrasco Chilón, William Leoncio; Alvarez Garcia, Wuesley Yusmein; Cervantes Peralta, Marieta Eliana; Quilcate Pairazamán, Carlos Enrique; Vásquez Pérez, Héctor Vladimir
The rye (Secale cereale L.) crop shows a high potential to contribute to the sustainability of high Andean livestock because it supports the agroclimatic conditions and acid soils in the Peruvian Andes. The production of green forage, hay, and grain from the rye crop in acid soils was studied with the use of different levels of phosphorus and potassium fertilization in four local rye ecotypes (CBI-001, CSM-001, CJS-001, and CCE-001). The green forage yield (GFY) ranged from 32.35 to 53.62 t ha−1, dry matter from 6.05 to 8.56 t ha−1, and hay from 7.0 to 10.36 t ha−1; nutritional levels ranged from 9.02% to 13.56% protein and 6.50% to 7.75% ash levels, mainly with differences between ecotypes (p < 0.05). No differences existed between fertilization levels for the number of stems per plant, spikes per plant, and grains per ear (p > 0.05). Also, CBI-001 and CCE-001 were superior with 1868.4 and 1797.8 kg ha−1 of grain, respectively (p = 0.0072); the use of 60 kg ha of nitrogen, 120 kg ha−1 of P2O5, and 80 kg ha−1 of K2O gave higher grain and residue yields. The high nutritional value and yield of the rye ecotypes studied in acid soil conditions and without irrigation can be an alternative for livestock feeding and grain production in the rainy season in the Andes as a dual-purpose crop.
Rye production under acid soils and drought conditions: An alternative for the sustainability of High Andean livestock farming in Peru
(MDPI, 2023-07-24) Carrasco Chilon, William Leoncio; Alvarez García, Wuesley Yusmein; Cervantes Peralta, Marieta Eliana; Quilcate Pairazamán, Carlos Enrique; Vásquez, Hector V.
The rye (Secale cereale L.) crop shows a high potential to contribute to the sustainability of high Andean livestock because it supports the agroclimatic conditions and acid soils in the Peruvian Andes. The production of green forage, hay, and grain from the rye crop in acid soils was studied with the use of different levels of phosphorus and potassium fertilization in four local rye ecotypes (CBI-001, CSM-001, CJS-001, and CCE-001). The green forage yield (GFY) ranged from 32.35 to 53.62 t ha−1, dry matter from 6.05 to 8.56 t ha−1, and hay from 7.0 to 10.36 t ha−1; nutritional levels ranged from 9.02% to 13.56% protein and 6.50% to 7.75% ash levels, mainly with differences between ecotypes (p < 0.05). No differences existed between fertilization levels for the number of stems per plant, spikes per plant, and grains per ear (p > 0.05). Also, CBI-001 and CCE-001 were superior with 1868.4 and 1797.8 kg ha−1 of grain, respectively (p = 0.0072); the use of 60 kg ha of nitrogen, 120 kg ha−1 of P2O5, and 80 kg ha−1 of K2O gave higher grain and residue yields. The high nutritional value and yield of the rye ecotypes studied in acid soil conditions and without irrigation can be an alternative for livestock feeding and grain production in the rainy season in the Andes as a dual-purpose crop.
Substrate, moisture, temperature and seed germination of the threatened endemic tree Eriotheca vargasii (Malvaceae)
(Universidad de Costa Rica, 2018-07-04) Mamani Mamani, Godofredo; Chuquillanqui Soto, Héctor; Chumbiauca Mateo, Susana Lourdes; Sahley, Catherine; Alonso, Alfonso; Linares Palomino, Reynaldo
We studied the germination of Eriotheca vargasii (Malvaceae), a poorly known endemic Peruvian Andean tree species characteristic of the dry forests of the Torobamba river valley, Peru. We determined seed characteristics, embryo morphology, viability, and assessed the influence of substrate (natural soil and commercially prepared media), temperature (controlled at 25 ºC and at ambient temperature between 18-22 ºC), and moisture (25 % and 50 % field capacity) on seed germination. Most seeds were ovoid in shape and although they contained well-developed embryos, only 46 % of them were viable. Substrate moisture levels had no influence on germination capacity or rate. In contrast, temperature and substrate type showed strong effects on germination. We observed the highest proportion of germinated seeds in prepared media at both temperatures tested (> 61 %). Furthermore, substrate types also influenced germination rates, with lower values in natural soil. The strongest effect on germination rates was by temperature, enhancing the difference in responses in substrate types (up to 90 % in commercially prepared media at 25 ºC). The low proportion of germinated seeds in soil (< 39 %), together with external local stress factors (e.g. grazing impact by herbivores), may be the critical factors contributing to the nearly total absence of seedlings and saplings of E. vargasii in the study area despite abundant seed production. In order to ensure a supply of E. vargasii seedlings for reforestation efforts, we recommend producing E. vargasii plants in nurseries and conducting reforestation trials. We suggest that germination of seedlings is done following guidelines from this study.
Utilización de los índices de selección en la identificación de genotipos de arroz (Oryza sativa L.) tolerantes a sequía
(Universidad Católica de El Salvador, 2024-02-10) Heros Aguilar, Elizabeth; Gómez Pando, Luz Rayda; Sosa Peralta, Guillermo
Doce genotipos de arroz fueron estudiados en condiciones de campo, en condiciones inundadas y en ambientes de sequía moderada y severa. Se utilizó el diseño de parcelas divididas con dos repeticiones, ubicando en parcelas los tratamientos de manejo de riego (tres) y en sub-parcelas los genotipos (12), con una separación de diez metros para controlar la filtración lateral. La siembra directa se realizó en hileras, utilizando una densidad de 80 Kg ha -1 . El rendimiento en grano se ajustó a 14 % de humedad. Para cada genotipo se determinó la tolerancia a sequía utilizando los siguientes índices de selección: Índice de Susceptibilidad al Estrés (ISE), Productividad Media Geométrica (PMG), Productividad Media (PM), Media Armónica (MA), Índice de Tolerancia al Estrés (ITE), Índice de Rendimiento (IR), Índice de Estabilidad de Rendimiento (IER) e Índice de Resistencia a Sequía (IRS). Se observaron diferencias significativas entre rendimientos en condiciones de inundación y estrés en los índices Productividad Media Geométrica (PMG), Media Armónica (MA) y Productividad Media (PM). Los coeficientes de correlación indican que estos índices podrían ser utilizados para la identificación de genotipos de arroz tolerantes a sequía. Los análisis de los gráficos tridimensionales indican que IR71706 es el genotipo más tolerante a sequía y puede sembrarse en condiciones de riego y aridez.