Abstract Brown rot and blossom blight caused by fungi of the genus Monilinia are the most important peach diseases. The increased concern with the environment and the health of workers and consumers, as well as the emergence of fungus isolates resistant to the main fungicide molecules favor control strategies such as genetic resistance. The objective of this study was to adjust a phenotyping protocol for evaluation of resistance/susceptibility to blossom blight in peach, as well as to quantify the antioxidant compounds present in the petals of these flowers and their correlation with the disease incidence and severity. The experiment was arranged in a randomized complete block split-split plot design, the plot being four concentrations of Monilinia fructicola conidia; the subplot two phenological flower stage; and the sub-subplot four peach genotypes. The quantification of antioxidant compounds and their correlation with susceptibility to blossom blight was performed in the four genotypes analyzed. Phenotyping was more efficient when concentrations between 400 and 4,000 conidia mL-1 were used, regardless of phenological flower stage. The phenolic compounds, anthocyanins and antioxidant activity are positively correlated among them, and negatively correlated with the blossom blight incidence and severity. In order to estimate the blossom blight susceptibility, it is recommended to use flowers at the pink or bloom stage, inoculum equivalent to 20-200 conidia per flower, and perform the evaluation at 96 hours after inoculation. This study suggests that more intense pink flowers have a higher content of antioxidant compounds and less blossom blight susceptibility.

Abstract A peach breeding program started in 1963, at the Experiment Station of Pelotas, nowadays Embrapa Clima Temperado, whose primary aim was developing cultivars adapted to mild winter conditions. Its first priority was to obtain cultivars of canning type fruits, and over the years, the fresh market cultivars acquired equal importance. This article analyzes the data of 84 fresh market cultivars, obtained in Pelotas, from 1964 to 2017, focusing on the following parameters: time of ripening, fruit development period, average fruit mass, number of fruits per tree, productivity per plant and total soluble solids. First, the data were tabulated, divided into two periods (1964-1984 and 1985-2017), and the descriptive statistical analysis was performed, followed by an analysis via mixed models and estimates of genetic progress via meta-analysis. The main results revealed a reduced fruit development period of the fresh market peaches belonging to that program. It was also observed a significant spread of the time of ripening (end of September or beginning of October until January), with a slight tendency for earliness. Genetic gain was observed for yield corresponding to 1.17 and 2.25% per year, for 1964-1984 and 1985-2017, respectively.

Resumo Em 1963, começou na Estação Experimental de Pelotas, hoje Embrapa Clima Temperado, um programa de melhoramento de pessegueiro cujo objetivo fundamental era desenvolver cultivares adaptadas a condições de inverno ameno. Inicialmente, a prioridade era a obtenção de cultivares produtoras de frutos para enlatamento, mas, ao longo dos anos, cultivares para o mercado fresco adquiriram a mesma importância. Este artigo analisa dados de 84 cultivares, tipo mesa, desenvolvidos em Pelotas, de 1964 a 2017, focando nos seguintes parâmetros: época de maturação, período de desenvolvimento do fruto, massa média dos frutos, número de frutos por planta, produção por planta e conteúdo de sólidos solúveis das frutas. Inicialmente, os dados foram tabulados, divididos em dois períodos (1964-1984 e 1985-2017), sendo então realizada a análise estatística descritiva, seguida por uma análise de modelos mistos e estimativa do progresso genético via meta-análise. Os resultados mostraram uma redução no período de desenvolvimento dos frutos das cultivares tipo mesa, pertencentes a esse programa. Houve ainda uma ampliação do período de colheita (do fim de setembro ou início de outubro até janeiro), com uma leve tendência à maior precocidade. Verificou-se um ganho genético para produção por planta, correspondendo a 1.17 e 2.25% ao ano, para os períodos de 1964- 1984 e 1985-2017, respectivamente.

ABSTRACT The adaptation of temperate fruit crops is a challenge being increased by the global warming. Chilling requirement is a key factor for adaptation. The objective of this study was to estimate the chilling requirement of peach cultivars BRS Bonão, Esmeralda, Granada and Eragil, using the Tabuenca test. Chilling accumulation was computed using four different chilling hour (≤ 7.2 ºC and ≤ 11 ºC) models; and chill units using the Low Chill model and the Taiwan model. The fresh bud weight and bud water contents were also evaluated. The Tabuenca test (based on differences in bud´s dry weight) showed a fairly good efficiency for estimating the end of dormancy in peach. However, under mild winter conditions, it is better to use fresh bud weights. Either one of three chilling accumulation computation models (temperature ≤ 7.2 °C, ≤ 11°C, or Taiwan model) is suitable to classify comparatively different cultivars, but none is accurate enough to conclude on the adaptation of a given cultivar to a specific site. Using hours of temperatures ≤ 11 ºC: ‘BRS Bonão’ needed around 180 hours for dormancy release; ‘Esmeralda’ around 250 hours; ‘Granada’ between 300 and 400 hours, and ‘Eragil’ more than 500 hours.

ABSTRACT. The fungus Monilinia fructicola, which causes brown rot in fruits, is one of the main peach pathogens. The emergence of fungicide-resistant fungus isolates, as well as the attempt to reduce sprays, favors adoption of other control strategies. Among them, one of the most important is genetic resistance. This study was carried out aiming to evaluate the susceptibility of 16 peach and 4 nectarine genotypes to brown rot, as well as to evaluate how well the sporulation area and diameter correlate with number of spores in the lesions. Both wounded and non-wounded fruits were inoculated with 10 μL of M. fructicola suspension. Wounded fruits from all genotypes (nectarines and peaches) showed susceptibility to M. fructicola, from 92 to 100% of incidence. The disease incidence was between 18 and 100% when non-wounded fruits were inoculated. High variability was detected for the fungus sporulation, in both wounded and non-wounded fruits, with ranges between 16 to 96% and 0 to 94%, respectively. The fungus sporulation was variable among the genotypes (between 0.1 to 96.0 conidia per mm2) and it is positively correlated with the diameter and area of sporulation. The genotypes Conserva 947, Conserva 1662, Conserva 672, Conserva 1600, and 'Bolinha', are the ones with less susceptible to brown rot.

ABSTRACT Blossom blight and brown rot caused by Monilinia fructicola is the most important peach disease in Brazil. Genetic resistance is a control strategy that is gaining importance in breeding programs worldwide. This study aimed to identify genotypes with higher levels of blossom blight resistance to estimate the heritability of this character; study the frequency distribution in populations; and test the possibility of maternal effect. Blossom blight susceptibility was tested in reciprocal hybridizations seedlings, as well as their parents. The detached flower technique was used in a randomized complete block design, considering each genotype as a treatment. Flower inoculation was made by spraying a M. fructicola suspension and evaluations were carried out after 72 and 120 hours using a scale of five severity levels. The studied populations presented low phenotypic variability regarding the flower resistance/susceptibility to M. fructicola, being most of them susceptible or very susceptible. Among the tested genotypes, the cultivars Maciel and Cerrito showed less blossom blight susceptibility, transmitting this character to their progenies. Heritability estimates of the blossom blight resistance were medium to low. The low heritability and its distribution in the progenies suggest that the character has additive inheritance, without detecting deviations associated with maternal effects.

Resumo O pessegueiro foi introduzido no Brasil no século XVI; mas, apesar disso, o primeiro programa de melhoramento só teve início no País, no fim da década de 1940. Mais tarde, outros programas foram iniciados, mas os maiores e que mais contribuições deram à cultura do pessegueiro foram o do Instituto Agronômico de Campinas e o da Embrapa Clima Temperado. Atualmente, o pessegueiro é cultivado não apenas nas áreas mais frias do Sul do Brasil, mas também nas áreas subtropicais e tropicais de altitude, graças às dezenas de cultivares lançadas por estes programas de melhoramento genético. A produção de pêssego brasileira destina-se ao mercado interno, e no maior centro consumidor do País, São Paulo, a preferência é por pêssegos com polpa branca, doces, com baixa acidez e aparência atrativa. A cultivar BRS Serenata está sendo lançada com o objetivo de preencher a lacuna de pêssegos de polpa branca, entre a estação de ‘BRS Kampai’ e ‘BRS Fascínio’.

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 Embrapa peach breeding program provides a processing peach cultivar, 'BRS Jaspe'. Over the years, the yield of this cultivar was stable and its fruits can be harvested by mid-November and have a good size and taste. It may represent an alternative to cultivar Granada, with a similar maturation period.

Abstract One of the reasons for the low market demand of blackberries in Brazil is the acid taste of the fresh fruit. The fruits of the newly released cultivar BRS Cainguá taste better and have a very attractive shape.

Abstract The peach breeding program of the Brazilian Agricultural Research Corporation (Embrapa), addressing the adaptation to mild winter conditions, is one of the largest in the world and maintains a germplasm collection of nearly 900 accessions. The objective was to estimate the genetic progress in fruit weight (FW) and fruit development period (FDP) resulting from the above program, by analyzing data records of 16 years (2000 - 2015) of 65 genotypes. Based on samples of ≥ 10 fruits, the mean annual FW (in g) and FDP (in number of days) from full flowering to harvest were determined. In the 16 years, the gain in FDP consisted of respective reductions of about -12.8, -3.3, -2.8 days for canning peach, fresh peach and nectarine. However, the genetic progress in fruit weight was 5.3, 1.4 and -17.9 g fruit-1 for canning peach, fresh peach and nectarine, respectively.

Abstract ‘BRS Citrino’ is a highly productive canning peach that has a round to conic shape. The flesh has a sweet acid flavor with a slight bitterness, giving a good quality product when canned. It is adapted to southern Rio Grande do Sul, where the production of processed peaches is concentrated.

RESUMO O pessegueiro tem grande importância econômica e social no Brasil. Diversas fontes de germoplasma foram utilizadas para a introdução de caracteres desejados no pool gênico de pessegueiro do Brasil, constituído principalmente de seleções naturalizadas e acessos selecionados a partir de populações desenvolvidas pelos programas de melhoramento, adaptadas às condições de clima subtropical, de baixa exigência em frio, bem como acessos introduzidos de diversos países. Neste estudo, foram utilizados marcadores SSR, selecionados por seu elevado nível de polimorfismo com objetivo de acessar a variabilidade genética e a estrutura populacional de um painel composto por 204 genótipos de pessegueiro, selecionados com base em fenótipos contrastantes para importantes caracteres no melhoramento do pessegueiro. Um total de 80 alelos foram identificados, com média de oito alelos por loco. Em geral, o valor médio da heterozigosidade observada (0,46) foi menor do que a heterozigosidade esperada (0,63). Análises do STRUCTURE atribuíram 162 acessos em duas subpopulações, majoritariamente com base em caracteres relativos ao fruto: cultivares fundentes (96) e não-fundentes (66). Os acessos restantes (42) foram considerados não-estruturados, utilizando um coeficiente de adesão de 80%. A variabilidade genética foi maior na subpopulação fundente em comparação com a não-fundente. Além disso, 55% dos alelos presentes nas cultivares e seleções do programa de melhoramento também estão presentes nos clones de fundação, indicando que estes clones estão bem representados nas cultivares de pessegueiro e seleções avançadas desenvolvidas. Este estudo apresenta uma primeira percepção da variabilidade genética disponível e evidências para a diferenciação da população (estrutura) neste painel de pessegueiro, que pode ser explorada e servir como base para estudos de mapeamento associativo.

ABSTRACT Peach has great economic and social importance in Brazil. Diverse sources of germplasm were used to introduce desirable traits in the Brazilian peach breeding pool, composed mainly by local selections and accessions selected from populations developed by the national breeding programs, adapted to subtropical climate, with low chill requirement, as well as accessions introduced from several countries. In this research, we used SSR markers, selected by their high level of polymorphism, to access genetic diversity and population structure of a set composed by 204 peach selected genotypes, based on contrasting phenotypes for valuable traits in peach breeding. A total of 80 alleles were obtained, giving an average of eight alleles per locus. In general, the average value of observed heterozygosity (0.46) was lower than the expected heterozygosity (0.63). STRUCTURE analysis assigned 162 accessions splitted into two subpopulations based mainly on their flesh type: melting (96) and non-melting (66) flesh cultivars. The remaining accessions (42) could not be assigned under the 80% membership coefficient criteria. Genetic variability was greater in melting subpopulation compared to non-melting. Additionally, 55% of the alleles present in the breeding varieties were also present in the founder varieties, indicating that founding clones are well represented in current peach cultivars and advanced selections developed. Overall, this study gives a first insight of the peach genetic variability available and evidence for population differentiation (structure) in this peach panel to be exploited and provides the basis for genome-wide association studies.

Resumo: O objetivo deste trabalho foi avaliar a herdabilidade no sentido amplo da reação à bacteriose foliar (Xanthomonas arboricola pv. pruni), em populações de pessegueiro obtidas de cruzamentos dirigidos. A severidade da doença e a desfolha dos genótipos foram avaliadas em campo, com posterior mensuração da duração da área foliar sadia (HAD). A herdabilidade média observada (0,51) indica que a utilização dos genitores avaliados pode ser efetiva para o desenvolvimento de cultivares com maior resistência à doença.

Abstract: The objective of this work was to evaluate the broad-sense heritability reaction to bacterial leaf spot (Xanthomonas arboricola pv. pruni), in peach tree populations obtained from directed crosses. Disease severity and defoliation of the genotypes were evaluated in field conditions, with posterior measurement of the healthy leaf area duration (HAD). The observed average heritability (0.51) indicates that the use of the evaluated genitors can be effective for the development of cultivars with higher resistance to the disease.

RESUMO Pêssegos tipo platicarpa tem alcançado ótimos preços devido à boa aceitação no mercado. Entretanto, a quase totalidade das cultivares lançadas são bastante exigentes em frio hibernal e não se adaptam às condições brasileiras, exceção representada por pequenas áreas de microclimas, com elevada altitude. A cultivar BRS Mandinho é a primeira cultivar da variedade botânica platicarpa lançada no Brasil e adapta-se a condições subtropicais. Suas plantas são vigorosas e a floração, no Rio Grande do Sul, ocorre na segunda quinzena de Julho. As frutas são doces e amadurecem em novembro e apresentam massa média de 55,3 g.

ABSTRACT In recent years, platycarpa peaches have reached high prices due to their good acceptance in the international market. However, the great majority of the released varieties are high chill and do not adapt to Brazilian conditions except on a few microclimes of high altitudes. The cultivar BRS Mandinho is the first peach cultivar of the botanical variety platicarpa, released in Brazil and adapted to subtropical conditions. The plants are vigorous and, in the state of Rio Grande do Sul, the blooming occurs on the second half of July. The fruits are sweet and ripe in November with an average weight of 55.3 g.

Brazilian peach breeding programs have been established to improve peach [Prunus persica (L.) Batsch] production, yield consistency, quality, and disease resistance. Every year several genotypes are selected and their traits must be assessed. This study aimed to evaluate adaptability and stability of fruit set and production of peach genotypes in a subtropical climate, using the GGE biplot methodology. The experimental design was completely randomized with three replicates (trees) in a factorial arrangement of 29 × 3 for genotype and growing season, respectively. The genotypes 'Conserva 1129', 'Rubimel', 'Kampai', 'Tropic Beauty', and 'Cascata 967' had the greatest adaptability and stability for fruit set. The genotypes 'Conserva 681', 'Santa Áurea', 'Atenas', 'Kampai', 'Cascata 962', 'Tropic Beauty' and 'Cascata 967' had the greatest production adaptability and stability. The GGE-biplot methodology classified the peach tree genotypes with regard to adaptability and stability of fruit set and production.

O objetivo deste trabalho foi identificar e caracterizar molecularmente os alelos-S de cultivares de ameixeira japonesa e verificar a compatibilidade gametofítica entre estes. Foram utilizados dois pares de iniciadores específicos na amplificação dos alelos via PCR, em 18 cultivares: Pluma 7, Gulf Rubi, Blood Plum, Wickson, América, Santa Rosa, Rosa Mineira, Estrela Púrpura, Amarelinha, The First, Harry Pieckstone, Santa Rita, Seleção 16, Seleção A26 (Burbank), Seleção 21, Seleção 19, Methley e Simka. As condições da PCR e as combinações de oligonucleotídeos iniciadores utilizadas permitiram a identificação de alelos-S nas cultivares, bem como a indicação dos polinizadores mais compatíveis. As cultivares América e Santa Rosa, bem como Blood Plum, Wickson, Rosa Mineira, Estrela Púrpura e Seleção 21 apresentam incompatibilidade total entre si, por compartilharem os mesmos alelos.

The objective of this work was to molecularly identify and characterize the S-alleles of Japanese plum cultivars and to verify the gametophytic compatibility between them. Two pairs of specific primers were used for allele amplification by PCR in 18 cultivars: Pluma 7, Gulf Rubi, Blood Plum, Wickson, América, Santa Rosa, Rosa Mineira, Estrela Púrpura, Amarelinha, The First, Harry Pieckstone, Santa Rita, Seleção 16, Seleção A26 (Burbank), Seleção 21, Seleção 19, Methley, and Simka. PCR conditions and oligonucleotide primer combinations used allowed the identification of S-alleles in cultivars, as well as the indication of the most compatible pollinators. América and Santa Rosa cultivars, as well as Blood Plum, Wickson, Rosa Mineira, Estrela Púrpura, and Seleção 21 show total incompatibility among each other, since they share the same alleles.