Cooperative Breeding Program Research Articles

Biological and Management-Related Predictors of Reproductive Success in North American Ex Situ Asian Small-Clawed Otters (Aonyx cinereus)

The long-term sustainability of ex situ animal populations requires coordination across facilities through cooperative breeding programs. Here, we investigate the reasons for inconsistent reproductive success in the zoo-based North American Asian small-clawed otter (ASCO; Aonyx cinereus) population. Reproductive viability analysis (RVA) was used to identify which characteristics of ASCOs in breeding pairs were most predictive of reproductive success. The RVA identified pair type, contraception history, and age as the most significant predictors of offspring production. The use of deslorelin in males and long-term deslorelin use in females hinder future reproductive potential and should, therefore, be considered carefully in genetically valuable individuals and potential breeders. Moreover, genetically valuable animals should be paired with younger mates, as advancing male and female age decreases the likelihood of success. The lack of reproductive success observed after 1 year of attempted breeding among new pairs provides evidence of potential mate incompatibility, therefore, population managers should consider splitting up pairs that remain unsuccessful over time, because the likelihood of offspring production is low. Lastly, the inclusion of dens and/or caves and pools designed with ample shallow water areas in ASCO habitats may improve breeding success.

European <i>ex situ</i> programmes for larger New World monkeys

Captive breeding programmes for primates can support the conservation of in situ populations of endangered species. European zoos, organised in the European Association of Zoos and Aquaria, keep almost 4000 larger Neotropical primates in their collections. Most of the species are managed in cooperative breeding programmes of various sizes. We report the current state of the European captive breeding programmes for these species and discuss the role assigned to each programme for the conservation of in situ primates. European zoos are successfully breeding most species currently kept under their care and are able to make an important contribution to the captive breeding of other, more endangered primate species, if requested by range countries. Many zoos that keep larger Neotropical primates provide financial or techni- cal support to in situ conservation projects.

Genetic trends of Mexican zebu cattle populations

In Mexico, the genetic evaluations in Zebu breeds began in 2011 and there are no studies about the genetic progress achieved. Thus, this research aimed to quantify and analyse the genetic progress for growth traits in the Mexican Zebu beef cattle populations Nellore, Sardo Negro, Gyr, Indubrasil, and Guzerat. The genetic trends were obtained through weighted regression (by the number of animals) of estimated breeding values for direct birth weight, direct and maternal weaning weight, yearling weight, and weight at 540 days of age, on the year of birth. Genetic trends were also estimated by the four selection paths, groups of herds, and weighted averages of the sires' breeding values. The results showed genetic gain as expected of genetic improvement. Nellore presented the highest positive gains for all the traits, and Gyr had the smallest gains among the breeds. Guzerat showed contrary trends for weights until weaning, and had more favourable trends for weights after weaning than the other breeds. The genetic gains obtained for the growth traits reflected the strong influence of the selection made via the maternal paths. The results between weighted and unweighted average breeding values indicate no effective strategy for disseminating genetic material with high breeding values. The genetic gains obtained in the whole populations were due to the main groups of herds. Thus, to achieve further genetic progress, it is necessary to design a cooperative breeding program with a strategy for disseminating that genetic material. Highlights The evaluated populations are developed in the context of tropical livestock, with specific selection criteria and objectives. Genetic trends assess the direction and magnitude of genetic change. The results in the genetic trends show the consequences of the genetic improvement schemes carried out by the breeders. For breeders, it is important to evaluate and monitor genetic improvement schemes, and where appropriate, adjust, or redefine selection criteria and objectives.

Expected demographic and genetic declines not found in most zoo and aquarium populations

Since the 1980s, animals in accredited zoos and aquariums have been managed as populations through cooperative breeding, with a goal of maintaining ex situ populations that are as demographically viable and genetically diverse as possible. Here, we provide what we believe to be the first large‐scale assessment of whether cooperative breeding programs are achieving this goal over time. Using a comprehensive dataset spanning nearly 20 years and encompassing more than 400 ex situ vertebrate populations, we applied Bayesian hierarchical modeling to quantify changes in seven population metrics over time. Instead of the general declines expected for small and often closed populations like those in zoos and aquariums, we found no change in the demographic and genetic characteristics of the majority of these populations. Our results indicate that while some zoo and aquarium populations are currently unsustainable, cooperative management is helping to slow or prevent declines in the health of many ex situ populations.

Host-associated microbiota of yellow stingrays (Urobatis jamaicensis) is shaped by their environment and life history

Insights gained from the unique scientific opportunities presented by public zoos and aquaria can help inform conservation and management decisions for wild populations and provide a rationale for decisions on exhibit design and maintenance for managed populations. This study has shown the diversity and composition of the microbiota associated with three different populations of yellow stingrays (Urobatis jamaicensis); wild rays (W), aquarium-housed rays originally caught in the wild (WC), and aquarium-born rays (AB). The microbial communities of wild rays were more diverse and had a different structure than did both WC and AB ray populations. Importantly, differences also existed between the two populations of aquarium-housed rays. There were significantly lower abundances of Bacteroidetes in skin-associated communities from WC rays v. AB rays, whereas there were significantly higher abundances of Vibrionaceae in cloaca-associated communities of WC rays v. those born in the aquarium. Additionally, the diversity of cloacal microbial communities was significantly lower in WC rays than aquarium-born rays. Findings from this study have demonstrated that a move from a wild to managed environment alters the host–microbe relationship in yellow stingrays and have lent support towards the refinement of aquarium disinfection strategies and expansion of cooperative breeding programs in the zoo and aquarium community.

Genomic Breeding Programs Realize Larger Benefits by Cooperation in the Presence of Genotype × Environment Interaction Than Conventional Breeding Programs.

Genotype × environment interaction (G × E) is of increasing importance for dairy cattle breeders due to international multiple-environment selection of animals as well as the differentiation of production environments within countries. This theoretical simulation study tested the hypothesis that genomic selection (GS) breeding programs realize larger genetic benefits by cooperation in the presence of G × E than conventional pedigree-based selection (PS) breeding programs. We simulated two breeding programs each with their own cattle population and environment. Two populations had either equal or unequal population sizes. Selection of sires was done either across environments (cooperative) or within their own environment (independent). Four scenarios, (GS/PS) × (cooperative/independent), were performed. The genetic correlation (rg) between the single breeding goal trait expressed in two environments was varied between 0.5 and 0.9. We compared scenarios for genetic gain, rate of inbreeding, proportion of selected external sires, and the split-point rg that is the lowest value of rg for long-term cooperation. Between two equal-sized populations, cooperative GS breeding programs achieved a maximum increase of 19.3% in genetic gain and a maximum reduction of 24.4% in rate of inbreeding compared to independent GS breeding programs. The increase in genetic gain and the reduction in rate of inbreeding realized by GS breeding programs with cooperation were respectively at maximum 9.7% and 24.7% higher than those realized by PS breeding programs with cooperation. Secondly, cooperative GS breeding programs allowed a slightly lower split-point rg than cooperative PS breeding programs (0.85∼0.875 vs ≥ 0.9). Between two unequal-sized populations, cooperative GS breeding programs realized higher increase in genetic gain and showed greater probability for long-term cooperation than cooperative PS breeding programs. Secondly, cooperation using GS were more beneficial to the small population while also beneficial but much less to the large population. In summary, by cooperation in the presence of G × E, GS breeding programs realize larger improvements in terms of the genetic gain and rate of inbreeding, and have greater possibility of long-term cooperation than conventional PS breeding programs. Therefore, we recommend cooperative GS breeding programs in situations with mild to moderate G × E, depending on the sizes of two populations.

Sugarcane and sugar yields in Louisiana (1911–2018): Varietal development and mechanization

AbstractLouisiana is the second largest producer of sugarcane (Saccharum officinarum L.) in the United States. New sugarcane cultivars better adapted for Louisiana have been in development since the inception of a three‐way cooperative breeding program in the 1920s. Piecewise regression is used to determine the growth in both Louisiana sugarcane and sugar yields and how new sugarcane cultivars and mechanization have had a positive impact of yields. The analysis uses several breakpoints for periods between 1911 and 2018 to consider the impact of varietal development and mechanization. In most cases, new sugarcane cultivars and changes in mechanization in Louisiana have significantly increased the yield of sugarcane and sugar. From 1911 to 2018, raw sugar yield increased at an annual rate of 0.061 t ha−1, while gross sugarcane yield increased by 0.47 t ha−1. Prior to 1927, yield growth was either negative or highly variable; since 1927, yield growth for both raw sugar and gross sugarcane have been positive and significant.

Patterns in the long-term viability of North American zoo populations.

Recent concerns about the viability of zoo populations have motivated studies on the historic and current status of animal populations in North American and European zoos. However, these evaluations may not accurately reflect the populations' long-term viability in the decades to come. Here, we assessed the projected future status of North American zoo populations by conducting standardized population viability analyses (PVAs) for 137 cooperative breeding programs. We summarized PVA results to describe patterns in viability across populations, and examined whether viability can be predicted by biological or management-based factors. Under recent management practices and without imports or exports of animals, 64% of populations will decline in size over the next 25 years, and only 18% would retain ≥90% of the founding gene diversity (GD) in 100 years. However, viability would improve if programs can implement management changes (e.g., increasing reproduction, increasing holding space, and importing genetically unique individuals, as appropriate): only 16% of populations would still decline in 25 years, and 49% would retain ≥90% GD in 100 years. Programs with more participating institutions and a "green" Association of Zoos and Aquariums animal program designation were projected to have higher metrics of demographic viability, and those with longer lifespans and lower recent death rates were projected to have higher metrics of genetic viability. Due to the large variation in species life history, management goals, and constraints across programs, our findings suggest there is unlikely to be a single path to long-term viability that would be appropriate for all zoo populations.

Improving the sustainability of ex situ populations with mate choice.

Many breeding programs managed by the Association of Zoos and Aquariums' (AZA) Species Survival Plans® (SSPs) are not meeting goals for population size and genetic diversity due to failure of recommended pairs to breed successfully. According to AZA Population Management Center analyses, as many as 80% of recommended breeding pairs fail to produce young before the next breeding and transfer plan is issued. Determining reasons for failure and ensuring that a specific pairing produces offspring can be challenging. Mate incompatibility, one possible reason for failure, might be addressed by allowing mate choice. Although many SSP® coordinators and breeding managers, who implement breeding recommendations at their institutions, recognize the potential benefits of mate choice, examples and models for presenting and assessing choice are lacking. Here we review examples from birds, rodents, lagomorphs, marsupials, carnivores, fishes, and insects where mate choice has been incorporated. These examples provide strong evidence that free mate choice and mating with preferred partners increase a variety of reproductive success measurements when compared to assigned mate pairings. We suggest innovative housing and breeding arrangements for better incorporating mate choice into the management strategies for species held ex situ. Further, we discuss the fitness consequences and welfare implications of allowing choice. We advocate for a more systematic use of behavioral research in cooperative breeding programs. Behavioral management for mating can yield more successful programs, thus ensuring SSP® genetic and demographic goals are met, while simultaneously improving welfare.

Collection planning for the next 100 years: What will we commit to save in zoos and aquariums?

The “sustainability crisis” in zoos and aquariums has been a sobering reminder of how limited our resources are for maintaining viable populations of species threatened with extinction. This, combined with increasing concern among the public about the value of zoos and aquariums, suggests that the zoological profession should engage in a thorough re‐examination of our guiding principles, philosophies, and practices with regard to collection planning at global, regional, and institutional scales. An analysis of AZA cooperative breeding programs reveals that in order to make these populations viable, many more founders and tens of thousands more spaces for animals, either in existing facilities or new ones, are necessary if we want to maintain all of the species that are covered by cooperative breeding programs currently. Regional zoological associations and their associated cooperative breeding programs must be more strategic and make more scientifically defensible decisions about which species to try and safeguard in zoos and aquariums. This would enable the zoological profession to give society a “Promise List” of species that we will commit to save from total extinction. Developing such a list will require a collaborative, inclusive process that transcends zoological regions. Regional association leaders, zoo & aquarium directors, and curators must make commitments to safeguard the species on the Promise List regardless of other interests. As our profession re‐examines its philosophies and practices and finds ways to increase its capacity to provide refuge for species facing extinction in the wild, it may be possible to expand the Promise List.

Use of molecular data in zoo and aquarium collection management: Benefits, challenges, and best practices.

The global zoo and aquarium community widely recognizes that its animal collections and cooperative breeding programs are facing a sustainability crisis. It has become commonly accepted that numerous priority species cannot be maintained unless new management strategies are adopted. While molecular data have the potential to greatly improve management across a range of scenarios, they have been generally underutilized by the zoo and aquarium community. This failure to effectively apply molecular data to collection management has been due, in part, to a paucity of resources within the community on which to base informed decisions about when the use of such data is appropriate and what steps are necessary to successfully integrate data into management. Here, we identify three broad areas of inquiry where molecular data can inform management: 1) taxonomic identification; 2) incomplete or unknown pedigrees; and 3) hereditary disease. Across these topics, we offer a discussion of the advantages, limitations, and considerations for applying molecular data to ex situ animal populations in a style accessible to zoo and aquarium professionals. Ultimately, we intend for this compiled information to serve as a resource for the community to help ensure that molecular projects directly and effectively benefit the long-term persistence of ex situ populations.

A Solution for the Shortage of Detection Dogs: A Detector Dog Center of Excellence and a Cooperative Breeding Program.

Currently, demand for US-bred and born detector dogs exceeds available supply, while reliance on foreign-bred sources introduces many unnecessary and unwanted risks. With proper management of a domestic supply line, U.S. breeders can improve both health and behavior by applying scientific principles to breeding and raising of detector dogs. A cooperative national detector dog breeding and development program will mitigate the current shortage of domestic-bred dogs that meet the health and behavior standards required by government, military, and law enforcement agencies. To coordinate such a cooperative, we propose a Detector Dog Center of Excellence (DDCoE) led by representatives of academic canine science programs guided by an advisory board of stakeholders. As a non-governmental organization, the DDCoE will oversee selective breeding of dogs owned by breeders, purchase the resulting puppies, and its members will supervise puppy raising until dogs are of a suitable age to be purchased by government agencies or other working dog organizations. The DDCoE will serve as an approved vendor to facilitate the procurement process. Breeding decisions will be based on proven quantitative genetic methods implemented by a specialized database. A national working dog semen bank will ensure conservation of diverse genetic material and enhance selection response by providing numerous potential sires. As a data collection and genetic evaluation center, the DDCoE will lead research to define quantitative traits involved in odor detection, to understand how these traits develop, and methods to optimize training of dogs endowed with enhanced odor detection ability.

Sugarcane Cultivars Descriptive Fact Sheet: CPCL 97-2730 and CPCL 00-4111

CPCL 97-2730 (Milligan et al. 2009) and CPCL 00-4111 (Glynn et al. 2011) are developed through the cooperative agreement between the United States Department of Agriculture (USDA), Canal Point, the university of Florida, Everglades Research and Education Center, Belle Glade and Florida Sugar Cane League. Prefix ‘CPCL’ in the name of these cultivars indicate that their crosses were made at the US Sugar Corporation, Clewiston (CL) and selection at different stages was carried through the cooperative breeding and selection program based at Canal Point (CP). Both are emerging sugarcane cultivars in Florida with their rapid expansion in last couple of years. CPCL 97-2730 and CPCL 00-4111 were ranked among the top 10 sugarcane cultivars in Florida in 2015 sugarcane variety census (VanWeelden et al. 2016) based on their total acreage. High biomass yield and better rust resistance than most commercial cultivars greatly improves the chances of their adoption by the growers. The purpose of this fact sheet is to provide basic information (Table 1) and yield and disease information (Table 2) about CPCL 97-2730 and CPCL 00-4111 to assist growers in decision making on further expansion of these cultivars.

Influence of Honey Bee Genotype and Wintering Method on Wintering Performance of Varroa destructor (Parasitiformes: Varroidae)-Infected Honey Bee (Hymenoptera: Apidae) Colonies in a Northern Climate.

The objective of this study was to assess the effectiveness of a cooperative breeding program designed to enhance winter survival of honey bees (Apis mellifera L.) when exposed to high levels of varroa (Varroa destructor Anderson and Trueman) in outdoor-wintered and indoor-wintered colonies. Half of the colonies from selected and unselected stocks were randomly assigned to be treated with late autumn oxalic acid treatment or to be left untreated. Colonies were then randomly assigned to be wintered either indoors (n = 37) or outdoors (n = 40). Late autumn treatment with oxalic acid did not improve wintering performance. However, genotype of bees affected colony survival and the proportion of commercially viable colonies in spring, as indicated by greater rates of colony survival and commercially viable colonies for selected stock (43% survived and 33% were viable) in comparison to unselected stock (19% survived and 9% were viable) across all treatment groups. Indoor wintering improved spring bee population score, proportion of colonies surviving, and proportion of commercially viable colonies relative to outdoor wintering (73% of selected stock and 41% of unselected stock survived during indoor wintering). Selected stock showed better "tolerance" to varroa as the selected stock also maintained higher bee populations relative to unselected stock. However, there was no evidence of "resistance" in selected colonies (reduced mite densities). Collectively, this experiment showed that breeding can improve tolerance to varroa and this can help minimize colony loss through winter and improve colony wintering performance. Overall, colony wintering success of both genotypes of bees was better when colonies were wintered indoors than when colonies were wintered outdoors.

Population management strategies for reducing koala retrovirus (KoRV) impacts on captive populations

This manuscript summarizes the break-out session held on population management strategies for reducing koala retrovirus (KoRV) impacts on captive populations at the Koala Conservation Workshop: The koala and its retroviruses: implications for sustainability and survival held at San Diego Zoo, April 17–18, 2013. The goals of this break-out session were to identify research and population management activities that could facilitate reducing KoRV impacts on captive koala populations. Although both goals were met and suggested activities identified, no long term modifications to current breeding strategies were agreed upon due to current gaps in knowledge about KoRV. Herein, proposed research and population management activities developed at the workshop are described. Ivy, Jamie A. 2014. Population management strategies for reducing koala retrovirus (KoRV) impacts on captive populations. In The Koala and its Retroviruses: Implications for Sustainability and Survival, ed. Geoffrey W. Pye, Rebecca N. Johnson and Alex D. Greenwood. Technical Reports of the Australian Museum, Online 24: 97–98. Cooperative breeding programs sponsored by regional zoo associations typically utilize breeding strategies designed to retain gene diversity and limit inbreeding. These goals are accomplished by iteratively breeding individuals with the lowest average kinship (or relationship) within a population; since these animals have the fewest relatives, they are genetically underrepresented and have higher probabilities of possessing genetic variation at risk of being lost. Can current breeding strategies be modified to reduce koala retrovirus (KoRV) expression in captive populations, while still maintaining the genetic and demographic viability of those populations? KoRV is known to be present in captive koalas throughout the US, Europe, and Australia. Given the regional representatives present at the Koala Conservation Workshop, the break-out session participants focused primarily on the management of populations in the US and Europe. Because additional koalas are expected to be imported into these populations from captive Australian populations in the next five years, ways in which future imports might impact the prevalence of KoRV in the US and Europe were considered alongside breeding strategy modifications. The discussion on possibilities for reducing KoRV expression in captive populations of koalas was primarily focused around two broad topics. The first topic was the need for additional, collaborative research on KoRV. In particular, it was suggested that increased testing for KoRV is needed and institutions that hold large numbers of captive koalas in the US and Australia should collaborate on both prospective and retrospective research. Studies on the association between disease and KoRV status are greatly needed to better inform modifications to population management. The second topic of focus was the implication of multiple KoRV variants being present in captive koala populations. Both KoRV-A and KoRV-B are present in the captive US population, with KoRV-A being the predominant variant. Because many break-out session participants were particularly concerned about disease associated with KoRV-B, actions or strategies that would limit or eliminate this variant in captive populations in the US and Europe were of particular interest.

Efficiency of selection for body weight in a cooperative village breeding program of Menz sheep under smallholder farming system

We evaluated the efficiency of selection for body weight in a cooperative village breeding program for Menz sheep of Ethiopia under smallholder farming system. The design of the program involved organizing villagers in a cooperative breeding group to implement selective breeding of their sheep. The program was jump-started through a one-time provision of elite rams from a central nucleus flock, but subsequent replacement rams were selected from within the village flocks. We also evaluated body weight trends in a village where cooperative breeding was not implemented and individual farmers managed their flocks under traditional breeding practices. Under traditional breeding practices, genetic progress over 8 years either stagnated or declined in all the weights recorded. In the cooperative villages, selection differentials of 2.44 and 2.45 kg were achieved in 2010 and 2011 selection seasons, respectively. Birth weight, 3-month weight and 6-month weight increased, respectively, by 0.49, 2.29 and 2.46 kg in the third-generation lambs over the base generation. Improved rams supplied from the central nucleus flock gave an initial genetic lift of 14.4% in the 6-month weight. This was higher than the gain achieved from selection in the village flocks, which was 5.2%. Our results showed that village-based genetic improvement in body weights under smallholder conditions could be feasible if appropriate designs are adopted and that commencing with elite central nucleus rams help jump-start village-based programs.

Registration of ‘CPCL 05‐1791’ Sugarcane

Development of ‘CPCL 05‐1791’ (Reg. No. CV‐156, PI 667555) sugarcane (a complex hybrid of Saccharum spp.) is the latest in a series of commercial sugarcane cultivar releases originating from the United States Sugar Corporation (USSC) and completed by the cooperative Canal Point sugarcane breeding and selection program (CP program) which includes the USDA‐ARS, the University of Florida, and the Florida Sugar Cane League, Inc. CPCL 05‐1791, which was released in Florida on 20 Sept. 2012, was selected from a cross of CP 96‐1252 × CL 90‐4725 made at Clewiston, FL on 5 Dec. 2002. The male parent, CL 90‐4725, is a proprietary cultivar of USSC. CPCL 05‐1791 was released because of its high cane yield, moderate levels of commercial recoverable sucrose on mineral (sand) soils, and its resistance to smut (caused by Ustilago scitaminea H. & P. Sydow), Sugarcane mosaic virus strain E (mosaic), and orange rust (caused by Puccinia kuehnii E.J. Butler), and its moderate resistance to brown rust (caused by Puccinia melanocephala H. & P. Sydow) and leaf scald (caused by Xanthomonas albilineans Ashby, Dowson). All of these diseases are of economic importance to sugarcane production in Florida.

Husbandry of a Lake Victoria cichlid, the Pitch‐black fulu Haplochromis piceatus, in public aquariums: a 20 year retrospective

The Lake Victoria haplochromine cichlids comprise a unique ‘species flock’ of over 500 historic species, of which perhaps only half still exist because of the introduction of invasive species and eutrophication of the Lake. Dr Les Kaufman supervised the establishment of captive populations of those cichlids he was able to acquire from Africa and Europe by developing the first North American regional studbook. Long‐term propagation of these fish was then undertaken by public aquariums in Europe and North America. One species, the Pitch‐black fulu Haplochromis piceatus, stands out as it has thrived at public aquariums and within the organizational structure of the Association of Zoos and Aquariums Species Survival Plans. These cooperative breeding programmes focus on the conservation of select species of threatened animals. Captive populations of H. piceatus at public aquariums in the United States show a relatively slow loss of genetic diversity. Additionally, fish in at least two breeding programmes show a higher than expected heterozygosity, indicating that these programmes are successfully keeping their fish from inbreeding. The husbandry and genetic management of this population of fish is outlined, hopefully providing useful information for nascent breeding programmes of other aquatic species at zoos and aquariums around the world.

Registration of ‘CPCL 00‐4111’ Sugarcane

‘CPCL 00‐4111’ (Reg. No. CV‐144, PI 660673) sugarcane (a complex hybrid of Saccharum spp.) is the latest in a series of commercial sugarcane cultivar releases developed by the United States Sugar Corporation (USSC) and completed by the cooperative Canal Point sugarcane breeding and selection program, which included the USDA‐ARS, the University of Florida, and the Florida Sugar Cane League, Inc. CPCL 00‐4111, which was released in Florida on 18 Feb. 2011, was selected from a cross of genotype CL 83‐3431 × CL 89‐5189 made at Clewiston, FL on 4 Dec. 1998. The female and male parents, CL 83‐3431 and CL 89‐5189, respectively, are proprietary genotypes of USSC. CPCL 00‐4111 was released because of its high cane yield and commercial recoverable sucrose on organic (muck) soils and because of its resistance to brown rust (caused by Puccinia melanocephala H. & P. Sydow), orange rust (caused by Puccinia kuehnii E.J. Butler), smut (caused by Ustilago scitaminea H. & P. Sydow), and Sugarcane mosaic virus strain E (the causal agent of mosaic), as well as its moderate resistance to leaf scald [caused by Xanthomonas albilineans (Ashby) Dowson]. All of these diseases are of economic importance to sugarcane production in Florida.

‘Andes-1’: An Early-maturing Clingstone Peach Cultivar for Canning and Fresh Market

‘Andes-1’ resulted from a cross made in 1998 at Santiago, Chile, between the Californian clingstone peach ‘Andross’ (University of California, Davis, 1964) and the selection A1-5A-85 from the Australis breeding program (a cooperative peach breeding program between the University of Chile and Andes Nursery Association). The main objective of Australis for peaches and nectarines is the development of high-quality-yielding earlyor late-maturing cultivars, which could be stored for at least 35 d in cold storage keeping a high flavor quality. Genotypes are intended to be grown in the central zone of Chile and other areas with a Mediterranean climate with medium chill requirements accumulation from 1 May to 15 Aug., 1000 chilling units according to the Utah model (Richardson et al., 1974). ‘Andes-1’ was selected after 4 years of field evaluation in the progeny plot and later tested on small plots of 15 trees budded on ‘Nemaguard’ rootstock. The experimental plots were established in Paine (long. 33 48#14.85$ S, lat. 70 40#6.54$ W) and El Tambo (long. 34 28#21.77$ S, lat. 70 59#21.22$ W), two representative environments of the Chilean stone fruit production area. Data were collected from the experimental plots for additional 5 years.