Search

Se notifica la primera cita conocida de reproducción de martinete común Nycticorax nycticorax (Linnaeus, 1758) en la provincia de Gipuzkoa. En julio de 2023 se observaron dos individuos juveniles aún no totalmente desarrollados en el Parque Ecológico de Plaiaundi (estuario del Bidasoa). ABSTRACT: The first known breeding record of the night heron Nycticorax nycticorax (Linnaeus, 1758) in the province of Gipuzkoa is reported. In July 2023, two juvenile individuals with vestigial plumage from previous stages were observed in the Plaiaundi Ecological Park (Bidasoa estuary).

ABSTRACT This study used a pedigree analysis to monitor trends in the genetic structure of the Mangalarga breed and identify factors that could impact its genetic variability. For this, genealogical information was used from the Associação Brasileira dos Criadores de Cavalo da Raça Mangalarga, considering as total population (TP) the animals born between 1919 and 2018 (n = 206,426) and as reference population (RP) those born between 2009 and 2018 (n = 20,539), which is the most recent generation according to the average generation interval calculated for the breed of 9.37 years. We evaluated the number of male and female births per year, foals produced by Mangalarga breeding animals, using the ENDOG 4.8, generation interval, proportion of known ancestors per parental generation, number of equivalent generations known per animal, inbreeding coefficient, increase in inbreeding, average relatedness (AR), effective population size, effective number of founders, effective number of ancestors, and founder genome equivalent. The number of equivalent generations known per animal increased over time, reaching an average of 2.75 in TP and 4.88 in RP. The calculated F was 2.26% for TP and 5.57% for RP, while AR was 2.41% for TP and 4.10% for RP. The effective population size was 40.85 for TP and 38.89 for RP. The 206,426 registered Mangalarga horses (TP) were derived from the genetic contribution of 9,011 founders and 8,908 ancestors, whereas those registered in or after 2009 (RP) originated from 2,662 founders and 2,193 ancestors. The effective number of founders represented 1.11 and 1.35% of the total number of founders in TP and RP, respectively. For RP, 11 animals accounted for 29.21% of the genetic pool of the breed. The analysis of population parameters estimated in the present study indicates that the Mangalarga horse population was formed through uneven contributions from founders and ancestors; therefore, genetic management of the breed is required to restrict average inbreeding from increasing over generations.

Cocoa cultivation plays an important role in Colombian rural development. In addition to being identified as a potential substitute for illicit crops, cocoa provides a livelihood for some 65,000 families in Colombia. However, the low productivity of the crop indicates that its potential is still limited. The objective of this research was to evaluate the cocoa cultivar CNCh12, previously selected by Compañía Nacional de Chocolates’ breeding program, and to compare its traits with a commercial cultivar, the CCN51 clon. For both cacao cultivars the next variables were measured: productivity (Kg/Ha/year), sexual compatibility, resistance to M. roreri, beans characteristics (physical, chemical and functional), morphological traits, and the flavor of cocoa liquor. The results indicate that the cultivar CNCh12 is highly productive, self-compatible, and with moderate resistance to Frosty Pod. This genotype also has fine and flavor attributes and functional traits that satisfy the chocolate industry needs. In this way, Compañía Nacional de Chocolates consolidates its position as the first private company to develop plant materials endorsed by the National Registry of Commercial Crops of the Instituto Colombiano Agropecuario-ICA, thus strengthening the genetic diversity that the country possesses.

Recent research on maize root architecture has made significant progress, but further research is needed to optimize methods for efficient and accurate acquisition of root architecture data. This study aimed to assess the effectiveness of digital imaging for root phenotyping of Zea mays L. Field experiments were carried out at two locations in the province of Antioquia, Colombia, in 2019 and 2020 to analyze root architecture variables of 12 genotypes of maize. Two methodologies were used: manual phenotyping and digital image analysis. Pearson’s correlation coefficients among variables were estimated. Principal Component Analysis (PCA) was used to summarize and uncover clustering patterns in the multivariate data set. The results indicated correlations between diameter (r = 0.94) and manually measured root diameter. The manually measured right and left root angles correlated with image-derived root angle at r = 0.92 and 0.88, respectively, and root length at r = 0.62. The PCA highlighted that the digital method explained the highest proportion of variation in root areas and diameters, while the manual method dominated in root angle variables. These results corroborate a feasible method to optimize root architecture phenotyping for research questions. This protocol can be adopted under the automatic analysis with REST software for acquiring images of variables associated with roots’ angle, length, and diameter.

ABSTRACT The objective of this study was to verify the repeatability of the expression of forage characters in intraspecific hybrids of Paspalum notatum Flügge to aid early selection. Across five harvests, plant height, tiller population density, leaf dry matter, stem dry matter, inflorescence dry matter, total dry matter, and growth habit were quantified for five parents, 189 hybrids, and a commercially available cultivar as a control (n = 195). Analysis of variance, principal components analysis, and structural analysis methods were used to determine the repeatability coefficients. The repeatability coefficients ( ρ ^) for all evaluated characteristics generated by the different methods were between 0.05 (ANOVA II) and 0.95 (PCACov). For most of the characteristics studied, repeatability coefficients and determination coefficients were considered high. The repeatability coefficients estimates obtained for the eight characteristics evaluated with the ANOVA I and II methods were almost always lower than those obtained by PCA and structural analysis methods. Based on the covariance matrix, the principal component method generated higher estimates than those produced by ANOVA or structural analysis. Assuming a minimum 80% reliability to verify the relative superiority of the hybrids across all assessed traits, the five harvests proved adequate for selecting the optimal plant materials to advance to the next phase of the breeding program. However, reliable early selection for leaf dry matter, leaf:stem ratio, and total dry matter required a minimum of two harvests. The genetic parameters (h2 and CVg) showed a favorable scenario for direct selection to increase forage production.

Gamma irradiation has been widely used as a breeding technique to obtain new cultivars in ornamental species such as Alstroemeria, where several cultivars have been obtained through rhizome radiation. The optimum dosage for an appropriate induction of mutation must be considered for breeding purposes and it depends mainly on plant susceptibility. Thus in this study in vitro cultured rhizomes of Alstroemeria aurea were irradiated with a gamma source using different dosages to evaluate the direct effect produced. Damage and number of rhizome sprouting were observed and recorded during 61 days after irradiation. At the end of this period, rhizomes were weighted and mortality was evaluated. Both mortality and weight increased depending on dosage. All irradiated rhizomes showed early sprouting in comparison with control (0 Gy) and no significant difference in final number of shoots after 61 days among irradiated treatments was observed. Bleaching and necrosis was observed in all irradiated rhizomes and was more evident at higher doses. LD50 was established at about 40 Gy and the optimum dosage to induce mutation was suggested between 2.5 and 5 Gy, when the growth was reduced in 50%, and probably this dosage could be used for breeding purposes.

Plant genetic resources for food and agriculture are ex situ conserved in germplasm banks as samples (accessions) of natural or naturalized populations, either as the originally sampled propagules (mainly seeds) or their multiplications. The premises underlying ex situ conservation are that (a) it is the safest and cheapest alternative for germplasm preservation for future generations and (b) accessions are representative of the genetic diversity encountered in nature. In the past decades, ideas, alternatives and considerations have been put forward on the topic, and protocols have been devised for plant germplasm sampling, conservation and multiplication. However, limitations in the management efficiency of germplasm banks have been pointed out by international organizations. In our opinion, germplasm banks in general need to revise their functioning and management at the light of principles and methods of Genetics. To that end, it is necessary to consider the reproductive biology of higher plants -whose genetic consequences at both the individual plant and the population levels are not always either fully understood or taken into account in devising the protocols-, the genetic structures of wild and cultivated populations, and the course of the genetic material in the populations. In this paper, we discuss the three topics and provide an example of a national forage breeding program, from germplasm bank accessions as the germplasm of origin to the obtainment of commercial cultivars. Finally, we present a proposal as a base for discussion among curators, researchers and breeders.

Los objetivos de este artículo son (1) calcular tendencias poblacionales para las aves acuáticas reproductoras en Euskadi durante el periodo 2005-2017, (2) estimar la importancia de los distintos humedales según su relevancia para las aves acuáticas nidificantes y (3) evaluar la metodología del programa de censo, con el fin de detectar posibles sesgos o carencias y proponer, en consecuencia, mejoras. De un total de 23 especies, 10 (43,5%) mostraron una tendencia incierta para el periodo 2005-2017. En el resto, la tendencia fue al alza en 6 especies, a la baja en 2 y estable en 5. En su conjunto, el programa de censo se ajustó bien a la monitorización de zampullines y somormujos, anátidas, rállidos y algunos limícolas, pero presentó déficits para especies coloniales que pueden criar fuera de humedales, como muchas ardeidas y cigüeña blanca, así como para las que utilizan hábitats fluviales. En estos casos, es recomendable llevar a cabo programas de censo de carácter complementario. Excluyendo tramos fluviales, los humedales más importantes para la reproducción de aves acuáticas en Euskadi se ubican en Álava. No obstante, los de la zona cantábrica, particularmente Urdaibai y Txingudi, muestran características particulares, dando lugar así a una alta riqueza y diversidad estructural para el conjunto del territorio. ABSTRACT: The aims of the present article were to (1) estimate population trends for breeding aquatic birds in the Basque Country during the period 2005-2017, (2) estimate the importance of different wetlands according to their relevance for aquatic birds and (3) evaluate the methodology of the programme in order to detect potential biases or shortcomings and propose improvements. Of 23 species overall, 10 (43.5%) showed uncertain trends, whilst for the rest the trend was positive in 6 species, negative in 2, and stable in 5. The census protocol seemed to be adequate for surveying grebes, ducks, coots and water rails as well as some waders, whilst it was not optimal for monitoring several species of herons, storks and those aquatic birds which breed along riparian flows. Complementary programmes and refined sampling designs are required for these last cases. Excluding riverine habitats, the most relevant wetlands for breeding aquatic birds within the region were in the province of Álava. However, the wetlands of the Cantabrian area, especially the estuaries of Txingudi and Urdaibai, showed a number of specific characteristics, thus giving rise to an increasing richness and structural diversity for the territory.

Abstract The objective of this work was to decompose the variations of the genotype × environment interaction through fixed multivariate models, as well as to understand the genetic variations through mixed models, for the estimation and prediction of the genetic value of soybean (Glycine max) genotypes in the state of Rio Grande do Sul, Brazil. Tests were carried out during the 2016/2017, 2017/2018, and 2018/2019 crop seasons in different municipalities in six regions of the state, using the additive main effects and multiplicative interaction (AMMI) and genotype main effects + genotype-by-environment interaction (GGE) models. The genotypes were also evaluated using an index that allows weighting between mean performance and stability (WAASBY) and by the restricted maximum likelihood (REML) and the best linear unbiased prediction (BLUP) models. The used experimental design was randomized complete blocks (18 environments x 12 genotypes), with three replicates. The best performing genotypes in favorable environments are: 'BMX Valente RR', 'BMX Alvo RR', 'NS 5959 IPRO', 'DM 5958RSF IPRO', and 'BMX Ativa RR'. The favorable environments are the 2017/2018 season in the municipality of Bagé and the 2016/2017 season in the municipalities of São Luiz Gonzaga and Cachoeira do Sul, where higher grain yields were obtained. The genotypes that show excellent performance in unfavorable environments are cultivars BMX Ativa RR, DM 5958RSF IPRO, NS 5959 IPRO, and TMG 7262 RR. The 2016/2017 season is considered unfavorable in the municipalities of São Luiz Gonzaga and Cachoeira do Sul. The AMMI, GGE, and WAASBY or BLUP models for genotype selection must be used simultaneously.

Purple-fleshed sweet potatoes (PFSP) are a new product for Uruguayan consumers. It shows differentiable sensory characteristics and added nutritional benefits, but sensory and hedonic expectations raised by PFSP have not been explored yet in Uruguay. The aim of this work was to explore Uruguayan consumers' perception of PFSP with a special focus on the hedonic, sensory and emotional expectations raised by them in comparison to traditional yellow and orange-flesh genotypes available in the market. A series of pictures of three types of SP were used in a social-network-driven study completed by 179 SP consumers. A word-association task and rating of expected liking together with exploring how they would feel after consumption using a check-all-that-apply (CATA) question composed of 21 emoji were carried out. Participants were also asked to describe the expected sensory characteristics using a CATA questions composed of 17 terms, selected based on results from previous sensory studies. Results revealed a lack of consumer familiarity with purple flesh coloration and lower expected liking scores compared to traditional orange and yellow flesh genotypes. It was also associated with scarce positive hedonic and emotional associations related to the emojis flushed face, face screaming in fear, grimacing face and weary face. Moreover, they were expected to have similar characteristics to yellow-fleshed sweet potatoes (YFSP) in terms of texture and flavor, being also associated with off-flavors presence. This highlights the need to develop diverse marketing strategies to increase familiarity before the commercial release of PFSP.

Il Palio di Ronciglione vanta una tradizione secolare, ma ciò che lo rende davvero unico è l’assenza di qualunque fantino. Alla caduta del canape ogni cavallo sceglie se competere con gli altri, accodarsi o semplicemente non correre, a seconda del carattere di ciascuno. Nel contesto del Palio il cavallo costituisce un co-produttore di processi culturali, che inoltre trasmette la sua esperienza agli esemplari più giovani; quest’ultimo aspetto è particolarmente evidente nelle traiettorie scelte durante la Corsa, fondate su un’incontestabile soggettività non-umana. Va rilevata una prima modalità di iscrizione ‘interna’ alla specie: i cavalli da corsa sono il risultato di una domesticazione secolare abbinata ad una selezione genetica controllata (breeding), che ha progressivamente embricato l’Equus ferus caballus alla società umana. Un secondo aspetto ‘esterno’ riguarda il tracciato della Corsa, vero e proprio ambiente di coesistenza inter-specie: realizzato dalla comunità umana, viene percorso ed esperito dai cavalli, che incidono il tessuto urbano con le loro traiettorie. L’agency dell’animale emerge dunque attraverso l’adattamento creativo al tracciato, un’iscrizione di geometrie non-umane nello spazio. L’intenzionalità del cavallo è ciò che fonda la performance del Palio: per quanto sembri paradossale, la conservazione di questo patrimonio culturale è possibile fintanto che il cavallo può scegliere di non correre.

Abstract The objective of this work was to analyze components of variances and heritabilities, estimate selection gain, and evaluate the different selection pressures for physical quality attributes of grains of families of segregating generations of irrigated rice (Oryza sativa), through the REML/BLUP methodology. The experiment was conducted in the state of Rio Grande do Sul, Brazil, where selections were made in the F3, F4, and F5 segregating generations, in the 2015/2016, 2016/2017, and 2017/2018 crop seasons, in eight segregating populations (families) from different crosses. Intrinsic physical quality attributes, genetic parameters, and response to selection were evaluated using different selection pressures. The obtained estimates showed genetic gains for the characters related to grain quality, mainly for total chalky area, vitreous whiteness, total whiteness, ratio between vitreous whiteness and total whiteness, and percentage of whole grains and broken grains, in selections in early generations. The used families show satisfactory results, being superior to the control cultivars. For most characters, the estimates of broad-sense heritability are considered intermediate, together with the other parameters, showing the possibility of genetic selection for grain quality attributes. The response to selection with a pressure of 10% is very promising for rice grain quality attributes.

Mandarin cultivars show a great diversity on fruit-quality and sensory characteristics, together with an extended harvest season. Citrus breeding is focused on exploiting season niches for higher prices as well as nutritional and sensory aspects, among others. In this context, the sensory characterization of new hybrids and the identification of key characteristics of consumers´ liking provide valuable information towards breeding efforts and marketing strategies. Previous works showed that sensory characteristics, and specially flavor, play a key role in consumer acceptance of mandarins. Two studies were carried out during mandarin harvest season (mid and late) applying “check all that apply” (CATA) questions with at least 100 consumers. Overall liking scores of the most liked hybrids and cultivars ranged between 6.5 to 7.7 in the 9-point hedonic scale, evidencing a positive hedonic reaction. Local hybrids showed similar or higher values than the reference cultivars Tango, Gold Nugget, Murcott and Ortanique. Results showed that orange color, regular shape, smoothness, sweetness, juiciness, intense and typical flavor are the key drivers of consumer's liking of mandarins, and that external appearance is not a good predictor of mandarin tasting experience. Hybrids F3P8, F5P8 and F2P3 were described using terms related to positive sensory characteristics and received liking scores similar or higher to reference cultivars such as Tango, stressing the importance of sensory and consumer science as an integral part of breeding strategies.

We reported the first data on the breeding and growth in Dendroplex picus peruvianus from a forest fragment in southwestern Amazonia. We observed and netted this species between 1999 and 2019. We found two active nests in 2012 and 2013, but we monitored only one. Clutch size was two eggs, incubated for 16 days. The constant growth rate (K) of nestlings was 0.31 with a growth asymptote of 46.3 g. We recorded a longest minimum longevity of eight years. Our records showed that D. p. peruvianus breeds mainly in the rainy season (September–March) overlapping with the molt period.

A better understanding of the key characteristics influencing consumers' perception and purchase decisions of mandarins can contribute to the selection of new cultivars that assertively meet their needs and expectations, as well as to the development of strategies to increase mandarin consumption in the different markets. In this context, the aims of the present work were: i) to explore Uruguayan consumers' perception of mandarins, and ii) to identify the key characteristics that drive mandarin purchase decisions. A consumer study with 197 consumers was conducted in a supermarket in the metropolitan area of Montevideo (Uruguay). A word-association task was used to identify consumers' associations with mandarins, whereas a best-worst scaling was used to estimate the relative importance of specific characteristics. Results from the word association task revealed that sensory characteristics (juiciness, sweetness, color, flavor and odor) were the most salient concepts associated with a mandarin, followed by fruit characteristics and consumption context. Mandarin flavor was identified as the most important characteristic underlying consumers' purchase decisions in the best-worst scaling, followed by juiciness and high vitamin content; while packaging, size or price resulted less relevant. Consumer segments who attached different relative importance to vitamin content, price, lack of seeds and easiness to peel were identified. Results from the present work suggest that strategies to increase mandarin consumption should focus on sensory and hedonic aspects rather than package appearance or health-related ones.

ABSTRACT Climatic conditions and microhabitat characteristics, such as the substrate and type of vegetation, influence the choice of male anurans for calling sites that optimize their reproductive success. We evaluated the structure and selection of vocalization microhabitat of 17 individuals of Phyllomedusa distincta Lutz, 1950 and 25 of Boana leptolineata (Braun & Braun, 1977), in a subtropical forest in southern Brazil. We measure the height of the perch, the distance between the perch and the edge of the body of water and the structure of the microhabitat of quadrants used by individuals. The same attributes were measured in the quadrants available (but not used) by the individuals. We classified the microhabitats by visual estimate, assigning percentages of coverage for each quadrant by herbaceous, shrub, tree and wetland vegetation. We observed that both species selected their microhabitat, since the characteristics of the quadrants occupied by the individuals were different from those available. Phyllomedusa distincta was more associated with heterogeneous microhabitats, while B. leptolineata occurred in environments with greater coverage of tree strata. Additionally, we observed that both species used shrubs more frequently as a perch site. The selection of these microhabitat characteristics must be associated with strategies to optimize the use of the reproductive habitat, based on the morphological and behavioral characteristics of the species. Finally, it is possible to infer that the differences observed in the microhabitat structure selected by the species can facilitate the coexistence of both in the context of the heterogeneity of the environment.

Fruit growing is the main agricultural activity of the Ariari region in the department of Meta. The cultivations of guava (Psidium guajava L.) and passion fruit (Passiflora edulis Sims) were established in the 1990s and currently about 2000 hectares of each crop are sown. In order to know the main phytosanitary problems and their management practices, a study was conducted with a survey of 40 guava producers and 43 maracuya producers in the Meta municipalities (Granada, Lejanías and Villavicencio). The information collected was socialized with the communities and the results were validated in-group workshops. The producers do not have support for technical assistance or agricultural extension services. We do not have the same technical means for the control of pests and diseases, neither the products nor the dose for their control; In addition to using products not recommended for these products or for phytosanitary problems. These management methods are higher than production costs and fruits. The implementation of the training of the producers and the evaluation of the biological control of the plagues and the practices of clean agriculture and the accompaniment of the programs of extension specialized in fruitculture is required.

Carnation is the most important flower in the exportation and the principal destination are United States of America and Europe and the country is the first producer of carnation in the word. The vascular diseases are the most important cause of losses in the crop and the most efficient method of control is to count to resistant varieties. The recognitions of the reproductive characteristics of the carnation hybrids, object of this work, permitted in a prudent period establish a program of varieties production in Colombia. In this work we used hybrids of three successive generations obtained by autopollination studding the reproductive characteristics. As much as pollen and ovules in the flowers, as well as in the male and female reproductive organs we find a high variability in the number of structures, were the reproductive variability is not bound to the endogamous generation. The pollen quantity is not directly bound with the number of seeds produced, as well as with the number of ovules in the gynoecium. Conversely, the seeds number is related directly with the number of viable ovules by flower. The hybrid fertility expressed in terms of number of pollen grains vs fertilized ovules and produced seeds by flower show that exist a plenty variability in the reproductive conditions in the hybrids, but enough to permit a successful production of seeds.

Vegetable growers are keen on cost-cutting measures to increase profitability. Containerized vegetable production can be done in a shade-house or garden, and it often requires commercial potting media. Although expensive, potting media are lightweight and provide high water- and nutrient-holding capacities, and thus they are widely used by growers. Growers often discard or compost the potting media after a single season due to issues such as diseases, pests, and weeds. However, old potting media could be reused for containerized production if appropriately sterilized and amended with fertilizer salts. The current study was conducted to determine the feasibility of using sterilized recycled potting medium amended with fertilizer salts for containerized production of squash. This new 4-page publication of the UF/IFAS Horticultural Sciences Department was written by Marie Dorval, Riphine Mainviel, Vincent Michael, Yuqing Fu, Bala Rathinasabapathi, and Geoffrey Meru. https://edis.ifas.ufl.edu/hs1404

In this current study, we examine the abundances and breeding phenology of three sympatric grebes (little, great crested and black-necked grebes) in Dayet El Ferd. These grebes were observed during all the period (2011-2018) in this wetland, except in September when the great crested grebe leaves the region. The abundances of these three grebes show a significant difference. In 2017, the total number of 71 nests was measured. The mean clutch size was 5.23 ± 1.49 eggs per nest. The highest number of eggs per nest was ten eggs, and most nests contained three eggs (N=18).

Abstract: The objective of this work was to evaluate five nonparametric selection indices for the selection of hybrid citrus rootstocks grafted with 'Valência' sweet orange, using horticultural traits relevant for the juice processing industry. Forty-six rootstocks were evaluated in a randomized complete block design, with three replicates and five trees in the plot, in the period from 2009-2015, in a rainfed cultivation. The means of the variables plant height, accumulated fruit yield, fruit yield efficiency, total soluble solids concentration, juice yield, and drought-tolerance were used to calculate the following indices: multiplicative index (IEi), sum of classification (IMMi), genotype-ideotype distance (DiI), and ranking indices (IRKi, based on simple means; and IRKii, based on linear normalization). The indices were efficient to classify the hybrids in relation to general performance. Spearman’s correlation showed a high similarity between most nonparametric indices, notably between IRKi and IRKii. The ranking indices, mainly IRKii, provide a more coherent classification of the hybrids, which allows of the selection of more productive and drought-tolerant rootstocks to produce high-quality fruit for processing.

ABSTRACT This study was conducted to investigate the growth hormone ( GH; somatotropin-like) gene polymorphisms in 150 water buffalo ( Bubalus bubalis ) from different regions of Turkey. 404 bp long partial intron 4, exon 5, 3’ UTR regions of the GH gene (also called GH/Alu I locus) and 347 bp long exon-intron 3 and partial exon 4 regions of the GH gene (also called GH/Msp I locus) were amplified, and their PCR products analyzed via DNA sequencing method. Seven genotypes due to twenty single nucleotide polymorphisms (SNP) and one deletion/insertion were identified in a 347 bp long region of the GH/Msp I locus. A missense mutation from glycine to glutamate amino acid and four silent mutations in the serine, threonine, and asparagine amino acids were determined in the exon 3 region of the GH gene. Four genotypes due to eight SNP were identified in a 404 bp long region of the GH/Alu I locus. A missense mutation from lysine to arginine amino acid and six silent mutations in Leucine, aspartate, histidine, lysine, arginine, and cysteine amino acids were revealed in the exon 5 region of the GH gene. The partial DNA sequence of the GH gene in water buffalos was reported, and these sequences were deposited at the NCBI Genbank database with the accession numbers MN266903-MN266909 and MN530973-MN530976. These SNP may have an effect on economic (such as body composition) and carcass traits, reproduction, and milk yield and content in water buffalo populations and may prove to be useful for water buffalo breeding.

In recent years, genome editing, using a system called CRISPR (clustered regularly interspaced short palindromic repeats) has raised incredible new possibilities for citrus improvement. CRISPR is being used to make small changes in the DNA sequence of citrus trees, resulting in specifically targeted mutations. Major advances in the ability to decipher the genetic blueprint of any living organism, including citrus, have been made possible by the development of new genome-sequencing technologies and powerful computers. Many commercially important citrus types have been or are in the process of being sequenced. Peer reviewed through UF/IFAS Citrus Research and Education Center; published in Citrus Industry Magazine.

Desde el primer caso de reproducción exitosa de la especie en la isla de Izaro (Bizkaia) en 2013, el gavión atlántico Larus marinus L., 1758 ha expandido su área de distribución a otras zonas de la costa vasca. El objetivo de este artículo es recopilar todas las citas disponibles sobre el proceso de colonización de esta especie que ha tenido lugar en las dos primeras décadas del presente siglo en la costa vasca. Esta colonización se inició a primeros de la década de 2010 y ha continuado en años posteriores. Durante el periodo 2012-2020, se localizaron 11 lugares en los que se detectó la presencia de gaviones emparejados en zonas aptas para la cría. Sólo tres llegaron a producir pollos (Izaro, Santa Clara y Txurruta). En 2020, la región albergaría un mínimo de tres parejas (en Santurtzi, Izaro y Santa Clara). Las parejas reproductoras se distribuyen por toda la costa, si bien de manera dispersa, en territorios que son defendidos, generalmente, dentro de colonias de gaviotas patiamarillas L. michahellis Naumann, 1840. El tamaño de puesta registrado en la costa vasca es de tres huevos (moda). La tasa de eclosión es de un 78,6% (n = 14), pero el porcentaje de nidos con huevos que llega a producir pollos que vuelan es un 64,2%. No se contabilizan en este cálculo las parejas en las que no llegó a haber puesta. Se confirma, en al menos 2 casos (Santa Clara y Txurruta), que el fracaso de las puestas se debe a molestias de origen humano, tanto en época de incubación como durante el momento de eclosión y cuidado de pollos. En otros casos, como Mollarri, es muy probable que las molestias causaran el abandono de los territorios antes de la puesta. Se anillaron pollos en Izaro, ininterrumpidamente a partir de 2013, y en Santa Clara en 2020. ____________________________________________ Abstract : Since its first breeding event on Izaro island (Bizkaia) in 2013, the distribution range of the great black-backed gull Larus marinus L., 1758 has expanded to other areas along the Basque coast. The aim of this paper is to compile all the breeding records of the great black-backed gull in order to document the colonisation process of this species along the aforementioned coastline. Colonisation started during the decade of 2010, continuing thereafter. During the period 2012-2020, we recorded 11 sites where the species was seen either breeding or paired in places adequate for breeding. Breeding was only detected at three sites (Izaro, Santa Clara y Txurruta). In 2020, the Basque coast would be the home for at least three pairs (in Santurtzi, Izaro and Santa Clara). The breeding pairs are found scattered along the whole coast in territories that are defended generally inside colonies of yellow-legged gull L. michahellis Naumann, 1840. The clutch size (mode) is 3 eggs, and the hatching rate is 78.6% (n = 14), though the percentage of nests with eggs producing fledgling chicks is 64.2%. It was confirmed at least in two instances (Santa Clara and Txurruta) that breeding failures were caused by disturbances of human origin, either during incubation or during the hatching and chick rearing period. In other cases, like Mollarri, it is reasonably likely that this type of disturbance caused an abandonment of the site even before the eggs were laid. Chicks were systematically ringed at Izaro from 2013, and in Santa Clara in 2020.

Abstract Even though the peach tree was introduced in Brazil during the XVI century, it was only on the 1940’s that the first peach breeding program started in the country. Later on, other programs started being, until now, the largest ones, and the programs that gave more significant contributions to the peach crop development those from the Instituto Agronômico de Campinas and from Embrapa Temperate Agriculture. Presently, peach is cultivated not only in the colder areas of the South but also in the subtropics and high altitude areas of the tropics, due to dozens of cultivars released by these breeding programs. Peaches are sold entirely in the domestic market and in the largest consumers market, State of São Paulo, the preference is for white sweet flesh and low acid peaches with attractive appearance. The ‘BRS Serenata’ cultivar was released to fulfill a gap of white flesh peach between the seasons of ‘BRS Kampai’ and ‘BRS Fascínio’.

ABSTRACT: The purpose of this study was to conduct selection, genetic parameter estimation, and prediction of genetic values for 18 S1 families of guava trees using mixed model methodology and simultaneous selection of traits by means of the additive selection index, multiplicative selection index, and mean rank adapted from Mulamba. All families analyzed were obtained by means of self-fertilization of superior genotypes (full siblings) from the genetic breeding program of guava trees at the Universidade Estadual do Norte Fluminense. An experimental randomized block design with 18 S1 families, three replicates, and ten plants per plot was used. A total of 540 genotypes (individual plants) of guava tree were evaluated. Genetic parameter estimation and selection of the best genotypes based on the genetic value were performed using the statistical procedure, from the Selegen-REML/BLUP program. The analyses of the additive selection index, multiplicative selection index, and the sum of rank adapted from Mulamba were also performed under the Selegen program. During the evaluation by the individual BLUPs, families 1, 12, 4, 6, and 8 contributed to most of the genotypes selected for the traits under evaluation, suggesting their significant potential to generate high quality and high yield genotypes. In the selection indexes via mixed models, the multiplicative index showed higher values for genetic gains (74 %), followed by the mean rank index adapted from Mulamba (19 %), and the additive index (2 %).

Abstract: The objective of this work was to obtain cowpea (Vigna unguiculata) progenies with compound inflorescences, short peduncles, early cycle, good plant architecture, and high-yielding potential. The initial genetic material consisted of 453 F2:3 progenies, selected from ten crosses and evaluated using Federer’s augmented block design, with two controls. Of these, 60 progenies from the F4:5 and F4:6 generations were selected and assessed in two consecutive experiments, both in a 8x8 lattice design with four controls and four replicates. Early selection was efficient at fixing the evaluated traits. A wide genetic variability was detected among and within progenies. The estimated and obtained heritability and genetic gains in the F4:5 and F4:6 progenies indicate the possibility of selection of early progenies with short peduncles, compound inflorescences, and productivity similar to or greater than that of the commercial cultivars used as controls.

Abstract: The objective of this work was to define an early selection strategy to identify Cabralea canjerana (Meliaceae) clones with high multiplication rate. A mini-garden of 109 clones of canjerana seedlings was established in a completely randomized design, in an acclimatized greenhouse. From seedlings, the mini-stumps and mini-cuttings were obtained. Mini-cuttings were collected at five different times, and the number of mini-cuttings per mini-stump, rooting percentage, and number of rooted mini-cuttings were quantified. The number of rooted mini-cuttings per mini-stump was the only trait that showed high correlation with the others. Five groups of clones based on the number of rooted mini-cuttings per mini-stump were separated using k-means clustering, and the genetic gain from selection and Pearson correlation were estimated. The selection of the two best groups in each evaluation period resulted in high genetic gains from selection for all evaluated traits. Early selection for the number of rooted mini-cuttings discarded 65% of the evaluated clones, which increases experimental precision in evaluations of traits associated with plantlet growth and quality. Early selection for the number of rooted mini-cuttings per mini-stump at different times allows the identification of Cabralea canjerana clones with high multiplication rate.

Abstract: The objective of this work was to determine the genetic progress of grain quality attributes of flooded irrigated rice (Oryza sativa) cultivars in the state of Rio Grande do Sul, Brazil, between 1972 and 2016. The genetic estimates followed an approach based on the comparative analysis of 25 cultivars released by Embrapa’s breeding program over this period. The experiment was implemented in four producing regions of the state of Rio Grande do Sul: Sul, Campanha, Planície Costeira Interna, and Planície Costeira Externa. The following significant genetic gains were observed: 0.20% per year, for percentage of whole grains after processing; -1.38% per year, for percentage of chalky kernels and white-core grains; -0.77% per year, for total chalky area; -0.08% per year, for total whiteness; and -0.82% per year, for non-vitreous grain whiteness. Most cultivars released have high amylose content and a low gelatinization temperature. Therefore, the breeding program presented significant annual genetic progresses between 1972 and 2016 for the main attributes of grain quality, and made cultivars available according to the national demand for grain quality in the several segments of the rice production industry.

The aim of this paper was to determine the size of the pre-ovulation follicle in the corpus luteum, and in blood progesterone on the sixth and twelfth days after ovulation, in Holstein, Brown, Swiss and Criollo breeds grazing in Ecuadoran Highlands. The size of the pre-ovulation follicle and corpus luteum, and the blood progesterone levels were determined on days six and twelve, in nine heifers from each breed. Assessment of ovarian structures was made by ultrasound scanning. The concentration of blood progesterone was determined by electrochemiluminescence. The pre-ovulation follicle in Criollo heifers was larger (14.6 ± 0.41 mm) than in Holstein (12.7 ±0.47 mm), and in Brown Swiss (12.7 ± 0.65 mm). The progesterone concentration on days six and twelve after ovulation of Criolla heifers was higher than for Holstein and Brown Swiss (11.0 ± 1.68 ng/ml, and 18.4 ± 2.04 ng/ml, respectively). The linear association values were high and significant (P < 0.05) in the pre-ovulation follicle, corpus luteum and progesterone, in Holstein and Brown Swiss. It was demonstrated that for every additional millimeter above the Criollo mean on the sixth day, 1.67 ng/ml more of progesterone was generated in Criollo heifers (P < 0.05) than in the rest. It was concluded that the Criollo heifers had higher progesterone levels than Holstein and Brown Swiss on the sixth and twelfth days, thus producing better conditions in the uterus, with lower early embryo losses.

The genetic diversity of maize populations, coupled with the efficiency and use of nutrients, allows the identification of populations that may be used as parents in future breeding programs. Thus, were realized four trials of maize populations in the year 2010, be two installate in inter-crop period and two crops period, in Center Agrotechnological - University Federal of Tocantins, in Palmas city of Tocantins State. At each period, populations were conducted under high and low N (150 kg ha-1 N and 0 kg ha-1 N) respectively in the coverage. The experimental design used in each trial was randomized blocks with three replications and 10 treatments. We studied the characteristic percentage of protein and determined the EUN by populations, using the methodology from Fischer. The genetic diversity was performed by multivariate procedures: Mahalanobis distance and grouping method of Tocher in the study of genetic diversity, each trial representing a distinct variable in the multivariate model. The lower content of protein were obtained under low N the crop period. The Populations POP 3 and POP 13 were efficiency and promising for protein production.

ABSTRACT Repeatability allows an estimation of the number of evaluations needed to optimize the selection of superior genotypes, with consequent effects on the research costs in terms of financial and human resources. The objective of this study was to estimate the coefficient of repeatability of biometric and yield traits, related to fruits and seeds of sacha inchi (Plukenetia volubilis), and to define the number of evaluations required for an efficient selection and evaluation of genotypes of the species. A total of 37 non-domesticated accessions were evaluated for 19 months in a randomized block design with 5 replications and 2 plants per plot. The total number of fruits, total number of seeds, total fruit weight, mean fruit weight, and number of seeds per fruit of the accessions were evaluated by monthly sampling. Additionally, seed biometry was assessed in a sample of 30 seeds per accession. Repeatability coefficients were estimated by analysis of variance, principal components and structural analysis. The principal component method based on the covariance matrix was the most appropriate for establishing repeatability estimates of sacha inchi, due to the cyclical nature of the crop. Superior genotypes of the species can be selected for yield-related traits with about 90% accuracy, from 5 harvests (months) onwards. To ensure this accuracy level, it would be necessary to evaluate a minimum of 5 and 25 fruits to determine mean fruit weight and number of seeds per fruit, respectively, and 39 seeds would be required to evaluate the biometric traits.

It’s no secret that HLB has challenged our juice industry to maintain the outstanding quality associated with Florida orange juice. Moreover, increased prices and competition from new juice products and blends have reduced Florida orange juice consumption. We believe that improving the quality, especially flavor and color, of our juice products, can help turn the situation around. The UF/CREC citrus improvement team has been engaged in sweet orange improvement since the mid-1980’s. Because the complex biology of sweet orange makes it difficult to directly breed new sweet oranges, our program has exploited other reliable sources of genetic variation, in addition to conventional breeding. Last year our group published an article in Citrus Industry describing how HLB-tolerant mandarin hybrids we are developing could be used to improve Florida orange juice (http://citrusindustry.net/2018/09/17/could-hlb-tolerant-mandarins-be-used-in-florida-orange-juice/). That article focused on research to gain a better understanding of the genetics that control fruit flavors, using sensory analyses (taste tests) to decipher flavor perception. Here, we provide an overview of our progress and strategies regarding the development of true processing sweet oranges with potential to enhance the Florida NFC portfolio, as well as the development of sweet orange-like hybrids that could be used to enhance Florida juice quality, or to produce new high quality stand-alone juice products.

The quality of pedigree information is extremely important in studies of population parameters and genetic diversity, as well as for selection of animals for use in breeding programs. The objective of the study was to estimate the average number of known generations of Lusitano horses (PSL) in Brazil, by means of analysis of the pedigree. The data used came from the Brazilian Lusitano Horse Breeders Association (ABPSL), from two populations: the total population with 18,920 animals born between 1912 and 2012, and the reference population composed of 8,329 animals, corresponding to the records of births from 2003 to 2012, used as reference of the active population and equal to the value (10.0 years) of the average generation interval of horses. The quality of pedigree information was determined by the average number of known generations and was represented in three different ways: number of complete generations (CG), indicating the number of generations with both progenitors known; number of generations (EG), calculated by summing all known ancestors, based on the calculation of (½) n, where n is the number of generations between the animal and every known ancestor, considered the best way to represent the pedigree information; and maximum number of generations (MG), providing the number of generations separating an individual from its most remote ancestor, regardless of whether both parents are known. The results were as follows: number of CG, 3.4 ± 1.1; number of EG, 5.5 ± 1.3; and MG value, 9.1 ± 2.6 for the total population. These were in the same order as for the recent population values of 3.8 ± 0.9, 6.3 ± 0.7 and 10.5 ± 1.5. The maximum results observed for the CG, EG and MG numbers were 6, 8 and 15 generations, respectively, for the recent population. The increased pedigree records of the recent population indicate improvements in the quality of genealogical information, consequently resulting in greater veracity in studies with the PSL breed in Brazil. It can be concluded that the quality of pedigree information improved in the most recent 10 year interval, but still presents record absences, detrimental to evolution and corrections in the breed, so the ABPSL should pay closer attention to the importance of the information in the records in order to obtain a better response to selection, greater accuracy and inclusion of new animals in breeding programs.

ABSTRACT This study evaluated morphometric and ultrasound information of tilapia (O. niloticus) breeders through multivariate analysis. We applied correlation, clustering, and principal component analysis to a dataset composed of information from 222 male and female breeders of the improved GIFT strain. The body weight, objective of the breeding program, showed a high positive correlation with most of the morphometric parameters. The formation of clusters indicated characteristics responsible for muscle composition and carcass weight. Some characteristics showed a high correlation, such as body weight and fillet weight (0.98 and 0.94 for females and males, respectively), and a high contribution to the explanation of data variability; of the total characteristics evaluated for females, two explained 75% data variability and four explained 72% for males. We concluded that it is possible to reduce the number of characteristics measured, as well as use information of average daily weight gain and body weight to select female and male breeders, respectively, to drive genetic gains favoring more productive generations.

This work aimed to study the association of four nitrogen use efficiency (NUE) methods and the genetic parameters of grain weight in two groups of maize genotypes, under different levels of nitrogen supply, in the season 2012/13. 16 field experiments were carried out in the city of Gurupi, Tocantins, Brazil. Each genotype group was evaluated in different seeding date, and each one was tested with different levels of nitrogen supply. In all experiments the experimental design was completely randomized blocks with three repetitions. The following trait was evaluated after stage R6: grain yield (GY), and after, four indices of efficiency/stress to nitrogen were estimated. The Pearson correlation coefficients, estimated among the indices, were all significant (P < 0.01). Among the seeding dates, the average heritability of GY was 54.4% and among the levels of nitrogen supply, the following values were observed: 60.4% (low N); 50.9% (medium N); 51.2% (high N). There is the possibility of the use of environments with lower nitrogen supply in the search for superior and more efficient genotypes for the GY, and based on our results, the Low N index is more adequate.

Research was done at the Center for Tropical Crop Research (INIVIT), to evaluate inflorescence of taro germplasm (104 accessions) in Cuba´s climatic conditions. Sampling was made every 7 days in the 2013-2014 period to evaluate inflorescence; accessions were characterized according to flowering parameters. The results showed that natural flowering by the 26-accession sample (25%), was observed to early blossom from July to October in 18 accessions (69.2%). Increased temperature and relative humidity lasted until November, when inflorescence ends.

Genetic improvement in beekeeping is mainly focused on increasing the productivity of various bee products, however, when thinking in terms of breeding, it is necessary to produce queen bees and to applicate selection in bee colonies. Even with the development of methods and technologies, there are few practical applications in the apiary. Thus, the aim of this study is to synthesize and disseminate the knowledge about the biology and behavior of queen bees, with further focus on the production of queens, as well as the instrumental insemination and selection, as tools for breeding programs. With the release of this knowledge it is expected that their application would improve the quality and quantity of bee products, keeping the colony with a selected queen, young and vigorous.

The geminivirus complex known as cassava mosaic disease (CMD) is one of the most devastating viruses for cassava (Manihot esculenta Crantz). The aim of this study was to use molecular-assisted selection (MAS) to identify CMD-resistant accessions and ascertain promising crosses with elite Brazilian varieties. One thousand two hundred twenty-four accessions were genotyped using five molecular markers (NS169, NS158, SSRY028, SSRY040 and RME1) that were associated with resistance to CMD, along with 402 SNPs (single-nucleotide polymorphism). The promising crosses were identified using a discriminant analysis of main component (DAPC), and the matrix of genomic relationship was estimated with SNP markers. The CMD1 gene, previously described in M. glaziovii, was not found in M. esculenta. In contrast, the CMD2 gene was found in 5, 4 and 5 % of cassava accessions, with flanking markers NS169+RME1, NS158+RME1 and SSRY28+RME1, respectively. Only seven accessions presented all markers linked to the CMD resistance. The DAPC of the seven accessions along with 17 elite cassava varieties led to the formation of three divergent clusters. Potential sources of resistance to CMD were divided into two groups, while the elite varieties were distributed into three groups. The low estimates of the genomic relationship (ranging from -0.167 to 0.681 with an average of 0.076) contributed to the success in identifying contrasting genotypes. The use of MAS in countries where CMD is a quarantine disease constitutes a successful strategy not only for identifying the resistant accessions but also for determining the promising crosses.

ABSTRACT This study assessed the risks of different management practices to increase pregnancy rate in beef cow-calf systems, aiming at assisting decision-making. The perception of 18 experts on animal sciences regarding the risks of 32 nutritional, breeding, and general management practices applied to increase pregnancy rate were evaluated through questionnaires. The experts were selected by a non-probability sampling of researchers on veterinary and animal sciences. In addition, five farmers and eight technical consultants were also selected. The questionnaire was applied during a face-to-face meeting. The risk of each practice was assessed according to four factors, namely, cost, technical knowledge, operational complexity, and flexibility, and an equation was developed to calculate this risk. The applied method allowed to determine the risk of each practice, obtaining results similar to those previously perceived by the experts. Operational complexity and cost had greater influence on the estimated risks compared with the other factors. Moreover, the increase of one unit in operational complexity and cost increased the perceived risk and the estimated risk scores in 0.43 and 0.28 points, respectively. Overall, the application of general management practices presented lower risk score compared with nutritional and breeding practices, which were not different from which other. Equations to estimate the risks of farm managers should routinely apply management practices to increase the efficiency of cow-calf production systems.

It is very likely that you have heard about the use of CRISPR technology and its great potential for addressing human health issues, as well as the promise it holds for providing solutions for major agricultural challenges, particularly for huanglongbing (HLB) in citrus. Granting agencies are supporting many citrus research projects aimed at developing resistance to HLB, through genome editing using CRISPR technology.

ABSTRACT: This research aimed at studying herbicides selectivity on individuals from three sugarcane families after different chemical managements in primary selection fields (F1). On the field, a randomized block design with five replications in a split plot scheme was used. Twelve herbicide treatments were allocated in the plots and the three seedlings families were allocated in the sub-plots. The herbicides treatments were T1- tebuthiuron POST-i + ametryn POST-t; T2- (diuron + hexazinone) POST-i + ametryn POST-t; T3- sulfentrazone POST-i + ametryn POST-t; T4- (diuron + hexazinone) POST-i + metribuzin POST-t; T5- sulfentrazone POST-i + metribuzin POST-t; T6- imazapyr IPP; T7- imazapyr IPP + ametryn POST-t; T8- imazapyr IPP + metribuzin POST-t; T9- imazapyr IPP + tebuthiuron POST-i; T10- imazapyr PPI + (diuron + hexazinone) POST-i; T11- imazapyr IPP + sulfentrazone POST-i and T12- weeded control. Families were F400 (IAC086155 x ?), F43 (IACBIO264 x IAC911099) and F14 (IACSP991305 x GlagaH). For each individual, the intoxication symptoms and the chlorophyll content on the leaves (40 and 120 DAApós-i), the percentage of live seedlings and selected seedlings (240 DAApós-i) were evauated. The chemical management with alternative treatments (T2 to T11) was selective to the three seedlings families because it caused slight intoxication symptoms and interference in the chlorophyll content, in addition to the high percentage of survival that allowed the plants selection for the later stage (F2). The management with herbicide applied in incorporated pre-planting (IPP) was highlighted as selective even when supplemented after the establishment phase of seedlings (POST-t).

One of the most challenging questions in plant breeding and molecular plant pathology research is what are the genetic and molecular bases of quantitative disease resistance (QDR)?. The scarce knowledge of how this type of resistance works has hindered plant breeders to fully take advantage of it. To overcome these obstacles new methodologies for the study of quantitative traits have been developed. Approaches such as genetic mapping, identification of quantitative trait loci (QTL) and association mapping, including candidate gene approach and genome wide association studies, have been historically undertaken to dissect quantitative traits and therefore to study QDR. Additionally, great advances in quantitative phenotypic data collection have been provided to improve these analyses. Recently, genes associated to QDR have been cloned, leading to new hypothesis concerning the molecular bases of this type of resistance. In this review we present the more recent advances about QDR and corresponding application, which have allowed postulating new ideas that can help to construct new QDR models. Some of the hypotheses presented here as possible explanations for QDR are related to the expression level and alternative splicing of some defense-related genes expression, the action of “weak alleles” of R genes, the presence of allelic variants in genes involved in the defense response and a central role of kinases or pseudokinases. With the information recapitulated in this review it is possible to conclude that the conceptual distinction between qualitative and quantitative resistance may be questioned since both share important components.

Caladiums are commonly grown in containers, hanging baskets or planted directly in the landscape as accent and border plants. Florida growers supply the majority of the caladium tubers used throughout the United States and around the world. The University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) has maintained a caladium breeding program at the Gulf Coast Research and Education Center (GCREC). This program released three new caladium cultivars, ‘Cosmic Delight’, ‘Fiesta’, and ‘Hearts Desire’, in 2015. This publication describes the origin and plant characteristics of these new cultivars, their tuber yield potential in production trials, and plant performances in container and landscape trials. These new cultivar introductions will be valuable to the Florida caladium tuber-production industry, the greenhouse/nursery industries, and commercial landscape maintenance companies.

In the medieval iconography, the documents which represent hens and henhouses are many and varied. They underline the importance of the poultry and of the eggs in the food balance of the population and give evidence of the significant role held by gallinaceans not only in the life of rural areas but also in the urban economy which is rapidly expanding.

The poultry farming little interested the historians of the medieval rural economy. The article reconsiders at first the question of the seigniorial levies of poultry, often quoted but little studied. Then two questioning could be asked: the generalization of the poultry breeding at the peasants and the outlets of the levies (nobiliary consumption or market). From two examples (Firenze and Languedoc), the article explains the organization of this market. At the end of the 16th century, medieval model is questioned. With the treaty of Prudent Le Choyselat, we attend a first attempt of economic rationalization by the development of an intensive and specialized breeding.

Despite the importance of traditional varieties of tomato (Solanum lycopersicum L.) as sources of variation in breeding programs and varieties targeted to high-price quality markets that value their exceptional organoleptic quality, little is known regarding the structure of these materials at the morphological level. In this study, a collection of 166 populations (137 of them during two years) of traditional varieties of tomato from the east coast of Spain has been characterized using 41 descriptors. The characterization revealed a considerable variation. The segregation observed in several populations (28 %) suggests that apart from the configuration as population varieties, the high variation present in these landraces may be partially due to possible seed mixing and spontaneous cross-pollination. Only nine fruit descriptors were required to represent the variation present in the collection analyzed. It seems that after spontaneous cross-pollinations, farmers applied strong selection to a small number of traits, though even in these traits a high level of variation is maintained. The variation observed may hinder clear recognition by the consumer, an attribute required for the consolidation of quality markets. Additionally, a registry of these materials as conservation varieties would be complicated considering the actual levels of variation. Therefore, a varietal depuration would be interesting in order to promotein situ conservation of these resources. Finally, the high levels of variation in the intra-varietal scale may justify the collection and maintenance of more populations of the same variety as the risk of conserving duplicates would not be so high.

El trabajo se llevó acabo en la Unidad Científico Tecnológica de Base (UCTB) Alquízar, adscripta al Instituto de Investigaciones en Fruticultura Tropical (IIFT), ubicada en la provincia de Artemisa, situada a los 22°77'45'' de latitud Norte y a los 82°56'28'' de longitud Oeste y a 6.80 m. s. n. m. Se realizó un estudio sobre 100 árboles de aguacate de diferentes grupos ecológicos propagados por semillas durante 7 años, teniendo en cuenta como variables principales: porte del árbol, tamaño de los frutos, época de cosecha y nivel de producción, plantados sobre un suelo Ferrasol Rhodic. Con los resultados de esta evaluación se seleccionó este cultivar, posteriormente se injertó sobre árboles a los que se le realizó el cambio de copas en el Banco de Yemas de UCTB y luego evaluar su comportamiento, mediante el descriptor IPGRI para el cultivo del aguacate, evaluándose 20 variables cuantitativas y 30 cualitativas de los frutos, además se determinó el crecimiento y la producción en kg/árbol en tres años de cosecha. Con los resultados obtenidos, se establecieron 25 árboles en el 2010 en la práctica productiva, en tres localidades del país: Güines, Pinar del Río y Jagüey Grande para determinar su comportamiento. El objetivo de este trabajo consistió en caracterizar y proponer un cultivar tardío de aguacate, para suplir los meses de enero-febrero, con lo cual se alargaría el período de cosecha de este frutal en el país y que al mismo tiempo reúna las exigencias de consumo nacional y para la exportación.