Jorge Manuel Revilla-Chávez

In this study parameters, correlations, and expected direct (DGg%) e indiretos (IGg%) genetic gains from mass selection and selection among progenies were estimated for growth, crown architecture, and reproductive traits in 105 open-pollinated Inga edulis progenies, 18 months old, established at three sites in the Peruvian Amazon, aiming at the simultaneous selection of multiple traits. Significant differences were detected among progenies for most traits within sites and joint sites. The estimation of narrow-sense heritabilities, mean-progeny heritability, and additive within progeny heritability showed that the traits are under genetic control and can be improved by mass selection or selection among progenies. The genotype-environment interaction was low for all traits, showing that selection can be carried out in only one of the site. The estimated genetic parameters were generally higher at site 1, indicating this site as more suitable for selection. The estimated genetic parameters were higher for diameter at breast height (D) in the joint site analysis, suggesting this trait as more suitable for direct selection. Genetic correlations were significantly greater than zero between D and the traits height, crown diameter, and fruit length, demonstrating that simultaneous genetic improvement of multiple traits is possible through direct selection for D. The greatest direct (DGg%) e indirect (IGg%) genetic gains were obtained through among and within progeny selection. The results show that crown architecture and reproductive traits can respond well to indirect selection based on direct selection for D.

The site index (SI) was evaluated in Guazuma crinita plantations for the Aguaytía River region, Ucayali, Peru, with seedlings from 200 open-pollinated families from 14 sites using a randomized block design in three sectors of the basin. At 48 months, the height (H), diameter at breast height (DBH), and the number of branches with leaves (C/Leaf) and without leaves (S/Leaf) of the trees in 11 plantations were measured. The population means were 9.8 cm (DAP), 1139.6 cm (H), 12.4 branches (C/Leaf) and 2.4 branches (S/Leaf), distributed in four phenotypic groups (G1, G2, G3, G4). Groups G1 and G3 presented greater growth in DAP and H. The correlations between SI and edaphic variables show a significantly positive association with calcium (Ca+2: 0.62), cation exchange capacity (CEC: 0.67), magnesium (Mg+2: 0.61), and pH (059), and non-significant negative association with texture (-0.38), sand (-0.38), potassium (K+: -0.15) and aluminum (Al+3: -0.39). Physiographic and climatic correlations indicate a significantly strong association between SI and elevation (0.85) and precipitation (0.97), while correlations between SI and DBH, H, basal area (BA) and volume (V) They have a high significance of 0.8, 0.7, 0.7 and 0.8, respectively. The middle and upper sectors of the basin present more favorable conditions for the development of commercial plantations that improve with the selection of the best phenotypic groups from the Río Aguaytía, San Alejandro, Río Curimana and Von Humboldt collection sites.

The aim of this study was to identify, characterize, and map mother trees of selected indigenous tree species to tackle shortage of high quality and quantity tree seed provision for massive plantation program by providing both temporal and spatial distribution of mother trees in the study area. This study identified 90 mother trees across seven indigenous tree species through stratified purposive sampling, treating each tree as an individual sampling plot to ensure localized data precision. Data on height, girth, and X ‐ Y coordinates of each mother tree, as well as nearby trees within 10 m. Radius from selected mother trees were recorded. Descriptive statistics and coefficient of variance were calculated for the collected data. Following the statistical analysis, the spatial distribution of the mother tree was mapped using ArcGIS software. Juniperus procera in Banja District shows the largest mean both in terms of DBH (116.21 ± 37.3 cm) and height (33.82 ± 4.07 m) while Podocarpus falcatus in Guangua District score the second largest mean for DBH (94.83 ± 15.1 cm) and height (32.28 ± 14.3 m). Prunus africana in Banja District 2 were the third largest from the characterized seed sources by scoring average DBH (91.98 ± 19.71 cm) and height (29.16 ± 6.27 m). The coefficient of variance of selected mother trees both by species and by forest name also indicate the suitability of selected forest for the production of high quality and quantity of tree seed. Spatial mapping and local knowledge were combined to point out specific seed collection sites, such as Ziqe Forest, and to determine optimal collection times. This research provides a data‐driven framework for developing targeted seed sourcing strategies that enhance the genetic resilience of restoration efforts, directly supporting Ethiopia’s national and international reforestation and afforestation commitments.

Carmenta foraseminis (Busck) Eichlin es considerada una de las principales plagas en el cultivo de cacao, por tanto, estrategias de control de fácil adquisición, preparación, uso y de bajo costo deben ser generadas. El objetivo fue determinar el efecto insecticida del extracto de hojas de Lonchocarpus utilis-LU sobre el control de Carmenta foraseminis en frutos de Theobroma cacao. Fue empleado un diseño de bloques completamente al azar (DBCA), con 6 tratamientos, 3 bloques y 10 frutos por parcela experimental. Los tratamientos fueron 6 concentraciones del extracto (T1:0%; T2:10%; T3:20%; T4:30%; T5:40% y T6:50%). Las variables evaluadas fueron: porcentaje de presencia de huevos en el fruto (PPHF), el porcentaje de eclosión larval (PEL), número de larvas eclosionadas (NLE), porcentaje de frutos atacados (PFA) y número de orificios (NO). Fue determinado que las concentraciones de 30% y 40%, tuvieron mayor capacidad de inhibición de eclosión de larvas de 10,89% al cuarto día y de 22,85% al sexto día de exposición. Las concentraciones de 30% y 40% fueron más eficientes en la reducción del ataque de la plaga, con 3.77% y 6,79% al cuarto y quinto día de exposición. En tanto, las concentraciones de 10% y 20% presentaron mayor ataque en 34% y 28% al cuarto y quinto día de exposición. Se concluye que, las concentraciones de 30% y 40% del extracto de hojas de Lonchocarpus utilis provocaron mayor eficiencia en el control de Carmenta foraseminis en frutos de Theobroma cacao.

Climate change and biodiversity loss pose critical threats to ecosystems, making reforestation with native species an attractive mitigation strategy. However, seedling production systems need to be optimized. This study aimed to evaluate the effect of different culture media and concentrations on the germination and in vitro morphological development of Calycophyllum spruceanum. A completely randomized design with five treatments was used: 100% Murashige and Skoog (MS), 50% MS, 100% Woody Plant Medium (WPM), 50% WPM, and a control treatment (agar), with seven replicates per treatment. Germination parameters were evaluated for 21 days, and morphological development at 70 days. The main results showed that WPM and agar obtained the highest germination percentages (73.33 and 75.24%, respectively) and germination rate (2.02 and 2.32 seeds per day, respectively), while WPM stood out in terms of final germination time. In morphological development, WPM recorded the highest values for number of leaves (8.18), nodes (5.25), plant height (16.83 cm), and fresh and dry biomass (147.27 and 16.07 mg), compared to the other treatments. In addition, principal component analysis showed that WPM was associated with germination and development variables, with significant correlations. In conclusion, the WPM medium optimized germination and promoted the development of healthy and homogeneous seedlings, positioning it as an efficient alternative for propagation, ecological restoration, and native species conservation programs.

Los hongos micorrizógenos arbusculares (HMA) constituyen un potencial microbiano, para su uso sostenible en la agroforestería y restauración ecológica. Actualmente en Perú la contribución de diversidad HMA es limitada y no existen reportes de la diversidad nativa de HMA asociados a plantas cultivadas de caoba (Swietenia macrophylla G. King), una especie forestal vulnerable, de interés en programas de reforestación y restauración ecológica. El objetivo de este estudio fue identificar la diversidad de morfoespecies de HMA en plantas cultivadas de S. macrophylla G. King, así como el número de esporas y porcentaje de colonización de HMA en cinco zonas de muestreo ubicadas en los departamentos de Ucayali, San Martín y Huánuco. Se emplearon quince individuos de S. macrophylla G. King por cada zona de muestreo. Se identificaron 35 morfoespecies de HMA en el área de estudio, encontrando mayor riqueza de morfoespecies en los distritos de Chazuta y Von Humbolth departamento de San Martin y Ucayali respectivamente. Las especies de HMA predominantes fueron las de las familias Acaulosporaceae y Glomeraceae con 13 en cada familia. Ambispora reticulata se encontró en común para cuatro zonas de muestreo; mientras que 19 morfoespecies se encontraron exclusivas de una zona de muestreo. El estudio reveló mayor número de esporas en las zonas de muestreo con plantas de menos de un año de establecimiento. El porcentaje de colonización no varió significativamente entre los sitios, donde se encontraron en promedio 42% de colonización por HMA en raíces en todas las zonas de muestreo.

Himatanthus sucuuba is important in folk medicine and is widely used as an antitumor, antifungal, vermifuge and anti-anemic agent1. In this context, the objective of this study was to develop a protocol for in vitro germination and micropropagation of H. sucuuba. The seeds were immersed in a 1.0% (v/v) Cabrio Top solution for one hour on a magnetic stirrer and then in a 0.1% (v/v) diluted NaOCl solution for 30 minutes under agitation, followed by immersion in 70% alcohol for 1 minute. Subsequently, the seeds were rinsed four times with sterile distilled water and then inoculated in MS medium supplemented with the auxins AIA, ANA and AIB at concentrations of 0.0; 1.0; 3.0; 5.0 mg L-1. The experimental design was completely randomized, using 10 treatments with 3 replicates of 10 seeds (n = 30). It was observed that the MS medium supplemented with IAA (5.0 mg L-1) resulted in 80% germination and seedlings with 5.97 cm in height and 4.2 nodal segments. To stimulate rooting, the nodal segments were cut and inoculated in MS medium supplemented with BAP (0.1 mg L-1) and in interaction with the auxins IAA, 2,4-D and ANA, at concentrations of 0.0; 3.0; 5.0 and 8.0 mg L-1 and kept in a growth room at 25 ± 2 °C, with a photoperiod of 16 h. The combination BAP+IAA (0.1 + 8.0 mg L-1) showed the best results with 100% sprouting, 40% callus formation and 30% rooting. In conclusion, in vitro propagation is a promising technique to produce H. sucuuba seedlings, however, hormonal adjustments are necessary.

The resilience of seedlings from four open-pollinated families of Swietenia macrophylla to simulated attacks by Hypsipyla grandella was evaluated at the nursery stage to determine the possibility of early selection of individuals from the most resilient families and establish sustainable forest plantations in the Peruvian Amazon. Significant differences were detected among families for diameter (D), sprout length (SL), and basal sprout area (BA). The coefficient of determination for genotypic effects was moderate (range: 0.248 – 0.457) for H (plant height), D, SL, and BA, and low (< 0.15) for plant base height (HB), number of sprouts (NR), number of branches (NB), and number of leaves (NL). The genetic correlation for the traits H, D, SL, BA, NR, NB, and NL ranged from 0.228 to 0.996, indicating that an increase in one of these traits can result in an increase in the other. This is important because there is the possibility of early selection of families for the traits D, SL, and BA for the development of plantations with families resistant to attack. Therefore, the genetic and phenotypic variation observed in the families suggests the possibility of early selection as a promising strategy for genetic improvement programs, using a larger number of families than those used in the present study, since theoretically larger samples may contain greater genetic variation between and within families.

El objetivo de este estudio fue determinar la respuesta y el desarrollo fisiológico in vitro de Guazuma crinita Mart. El experimento, conducido con diseño completamente al azar, evaluó 5 tratamientos con diferentes medios de cultivo y concentraciones: MS (T2), ½ MS (T3), WPM (T4), ½ WPM (T5) y como testigo (T1) se excluyeron los medios de cultivo y solo se utilizó agar. Cada tratamiento estuvo compuesto por 35 repeticiones, dentro de las cuales la unidad experimental fue un frasco con 4 semillas. Las variables analizadas fueron: porcentaje de germinación (%G), altura aérea (HP), número de nudos (NN), número de hojas (NH), masa fresca (MF) y seca (MS). Los principales resultados demostraron que la utilización de agar (T1) presentó el mayor porcentaje de germinación (63.28 %). En cuanto al desarrollo fisiológico, el medio WPM al 100 % (T4) obtuvo los valores más altos en altura aérea (17.59 cm/planta), número de nudos (5.25 nudos/planta), número de hojas (6.18 hojas/planta), masa fresca (192.8 mg/planta) y seca (24.1 mg/planta). Así mismo, se evidenciaron correlaciones positivas entre las variables estudiadas y, por otra parte, el PCA reveló diferentes agrupamientos entre todos los tratamientos. Estos resultados subrayan la relevancia de seleccionar medios de cultivo adecuados para optimizar tanto la germinación como el desarrollo fisiológico de G. crinita.

Aniba rosaeodora is a valuable species of the Amazon, being extensively logged to extract linalool - a secondary metabolite that fixes cosmetic perfumes, which has led to its overexploitation and near extinction. Forest conservation and management efforts are hampered by insufficient knowledge about the distribution of A. rosaeodoraseedling and population structure. Therefore, in the present study we sought to understand these patterns in a central-eastern tropical forest in the Peruvian Amazon, where seed dispersal result mainly from barochory and zoochory. The average distance of seedlings from their seed trees was 18.3 ± 9.3 m, with a maximum of 44 m from the seed tree, and the emergent population structure was 53.4% seedlings; 12.2% saplings; 27% stems and 7.4% adult trees, fitting the Weibull model (shape 2.1; scale 20.2). In selected plots, we observed population density ranging from 7 to 3.3 ind ha^-¹, with a low presence of adult trees (0.5 ind ha^-¹). Trees with diameters > 20 cm were grouped in clusters of 2 to 5 individuals, with a Morisita index of 1.97 in the F-distribution (p > 0.05) and were spaced on average 97 to 110 m apart. Our analysis indicated that the population was unsustainable, with a high probability of co-ancestry, as indicated by the exponential (R² = 0.98) and Liocourt’s quotient (q = 1.5-3). Nevertheless, the area holds significant potential for the conservation of the species’ genetic resources.