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Abstract Background Environmental adaptation and expanding harvest seasons are primary goals of most peach [Prunus persica (L.) Batsch] breeding programs. Breeding perennial crops is a challenging task due to their long breeding cycles and large tree size. Pedigree-based analysis using pedigreed families followed by haplotype construction creates a platform for QTL and marker identification, validation, and the use of marker-assisted selection in breeding programs. Results Phenotypic data of seven F1 low to medium chill full-sib families were collected over 2 years at two locations and genotyped using the 9 K SNP Illumina array. Three QTLs were discovered for bloom date (BD) and mapped on linkage group 1 (LG1) (172–182 cM), LG4 (48–54 cM), and LG7 (62–70 cM), explaining 17–54%, 11–55%, and 11–18% of the phenotypic variance, respectively. The QTL for ripening date (RD) and fruit development period (FDP) on LG4 was co-localized at the central part of LG4 (40–46 cM) and explained between 40 and 75% of the phenotypic variance. Haplotype analyses revealed SNP haplotypes and predictive SNP marker(s) associated with desired QTL alleles and the presence of multiple functional alleles with different effects for a single locus for RD and FDP. Conclusions A multiple pedigree-linked families approach validated major QTLs for the three key phenological traits which were reported in previous studies across diverse materials, geographical distributions, and QTL mapping methods. Haplotype characterization of these genomic regions differentiates this study from the previous QTL studies. Our results will provide the peach breeder with the haplotypes for three BD QTLs and one RD/FDP QTL to create predictive DNA-based molecular marker tests to select parents and/or seedlings that have desired QTL alleles and cull unwanted genotypes in early seedling stages.

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.

Ten phenological and fruit quality traits were evaluated in seedlings from nine F1 low to medium chill full-sib peach (Prunus persica) families and their parents over 2 years at two locations (Fowler, CA, and College Station, TX) to estimate variance components, genotype by environment interaction (G×E), and phenotypic correlations using restricted maximum likelihood mixed and multivariate models. The removal of nectarine [P. persica var. nucipersica (fruit without fuzz)] and pantao (flat shape fruit) seedlings from the analysis decreased the heritability for the fruit size, blush, tip, and soluble solids concentration (SSC), indicating the importance of taking the effects of the major gene of nectarine/pantao into account when assessing the heritability of traits. A strong correlation coefficient (r = 0.92) found between ripe date (RD) and fruit development period (FDP) and between fruit weight (FW) and fruit diameter (FD), indicates that either measure is equally effective, although the negative correlation between bloom date (BD) and FDP (r = −0.46) implies earlier blooming during cool temperatures tends to extend FDP. FW, FD, blush, and SSC had moderately weak correlations with RD (r = 0.56, 0.53, −0.41, and 0.48) and FDP (r = 0.57, 0.56, −0.50, and 0.39, respectively), which could be explained either by the presence of a strong link between quantitative trait loci of these traits and the ripening date locus or the pleiotropic effect of ripening date on many quantitative fruit characters. The traits RD, FDP, and titratable acidity (TA) had the highest broad-sense heritability (H2) and lowest G×E. FW, tip, and shape showed the lowest H2, the highest of G×E variance to the genetic F (G×E variance/total genotypic variance), and high G×E, whereas the other traits showed moderate G×E. For the traits that had a higher G×E interaction, selection for or against these traits should be done at the production location. A moderate narrow-sense heritability (h2) was estimated for BD, blush, fruit tip, and shape. FW and FD showed low to moderate h2 while H2 was high, whereas RD, FDP, SSC, and TA showed low h2 and high H2 estimates, indicating important nonadditive effects for these traits.

Abstract Background Fruit quality traits have a significant effect on consumer acceptance and subsequently on peach (Prunus persica (L.) Batsch) consumption. Determining the genetic bases of key fruit quality traits is essential for the industry to improve fruit quality and increase consumption. Pedigree-based analysis across multiple peach pedigrees can identify the genomic basis of complex traits for direct implementation in marker-assisted selection. This strategy provides breeders with better-informed decisions and improves selection efficiency and, subsequently, saves resources and time. Results Phenotypic data of seven F1 low to medium chill full-sib families were collected over 2 years at two locations and genotyped using the 9 K SNP Illumina array. One major QTL for fruit blush was found on linkage group 4 (LG4) at 40–46 cM that explained from 20 to 32% of the total phenotypic variance and showed three QTL alleles of different effects. For soluble solids concentration (SSC), one QTL was mapped on LG5 at 60-72 cM and explained from 17 to 39% of the phenotypic variance. A major QTL for titratable acidity (TA) co-localized with the major locus for low-acid fruit (D-locus). It was mapped at the proximal end of LG5 and explained 35 to 80% of the phenotypic variance. The new QTL for TA on the distal end of LG5 explained 14 to 22% of the phenotypic variance. This QTL co-localized with the QTL for SSC and affected TA only when the first QTL is homozygous for high acidity (epistasis). Haplotype analyses revealed SNP haplotypes and predictive SNP marker(s) associated with desired QTL alleles. Conclusions A multi-family-based QTL discovery approach enhanced the ability to discover a new TA QTL at the distal end of LG5 and validated other QTLs which were reported in previous studies. Haplotype characterization of the mapped QTLs distinguishes this work from the previous QTL studies. Identified predictive SNPs and their original sources will facilitate the selection of parents and/or seedlings that have desired QTL alleles. Our findings will help peach breeders develop new predictive, DNA-based molecular marker tests for routine use in marker-assisted breeding.

Background: In terms of breeding perennial plants, the Embrapa's blackberry breeding program is relatively recent. It started between the end of the 1970s and beginning of the 1980s with a very limited number of cultivars plus a fairly good number of seeds from hybridizations made at the University of Arkansas, USA. Objective: this paper aim to present, in a summarized way, the current stage and recent achievements regarding the top priorities of the breeding program Methodology: Controlled hybridizations is the main method used and adaptation to mild winters conditions besides a higher ratio (sugar/acid contents) are among the main objectives. Results: Other objectives include high productivity, large size and firm fruits, good post-harvest conservation, erect, thornless canes and harvest period at different time of ‘Tupy,’ the most important one, in Brazil. Implications: It is believed that in the coming years, the Brazilian market will learn to like fresh blackberry, mainly considering the release of ‘BRS Cainguá’ and others that hopefully will follow. Conclusion: The present status of the program and achievements related to the main goals are discussed. Advanced selections with potential to become a future cultivar are briefly described, emphasizing next probable releases.

Because of climatic changes, the cultivation of temperate climate plants such as peach in subtropical climates has become a challenge. In these areas, temperatures exceeding 25°C often occur during the pre-flowering and flowering phases. The high temperature causes damages by acting during the early stages of pollen-pistil interaction processes. The objective of this work was to evaluate the stigmatic receptivity of peach flowers at 18°C and 30°C. The pollen adherence was evaluated as well as the germination and presence of pollen tubes in the transmitting tissue of the style. The genotypes responded differently to temperature. ‘Granada,’ ‘Diamante’, and ‘Sensação’ had a stigmatic receptivity that was less affected when flowers were exposed to the higher temperature. Most genotypes showed a reduction in the number of pistils with pollen tubes growing in the style, particularly when pollination was delayed.

O objetivo desse trabalho foi avaliar o efeito da composição de diferentes substratos na produção de mudas de mirtileiro. Foram utilizadas mudas da cultivar 'Georgiagem', oriundas de multiplicação in vitro. Foram utilizados sete diferentes substratos, os quais são: T1 - Plantmax® (100%); T2 - Plantmax® + perlita (1:1); T3 - Solo + matéria orgânica + perlita (1:1:1); T4 - solo + casca de arroz (1:1); T5 - solo + composto industrial + vermiculita (1 :1:1); T6 - casca de acácia + solo (1:1); T7 - acícula de pinus + solo - (1:2). O substrato acícula de pinus + solo, seguido pelos substratos Plantmax®, casca de acácia + solo e casca de arroz + solo promoveram maior acúmulo de massa seca da parte aérea e raízes. Os substratos solo + composto industrial + Perlita e Solo + composto industrial + vermiculita, com pH alcalino, apresentaram menor produção de massa seca e menores concentrações de Fe, Mn, Zn, N e P. Os substratos acícula de pinus, casca de acácia + solo, casca de arroz + solo e Plantmax® com ou sem perlita, mostraram-se os mais adequados para a produção de mirtileiro, cultivar 'Georgiagem'.The research aimed to evaluate the effect of the composition of different substrate on the production of blueberry seedlings. The seedlings used were highbush, 'Georgiagem' from in vitro multiplication. Seven different substrate were used: T1 - Plantmax® (100%); T2 - Plantmax® + perlita (1:1); T3 - soil + composed industrial + perlita (1:1:1); T4 - soil + rice husks (1:1); T5 - soil + composed industrial + vermiculite (1:1:1); T6 - acácia bark + soil (1:1); T7 - pine needle mulch + soil (1:2). The substrate pine needle mulch + soil, followed by the substrate Plantmax®, acácia bark + soil and soil/rice husks + soil, which promoted greater dry mass of roots and shoots. The substrate Soil + composed industrial + perlita and soil + composed industrial + vermiculite, pH alkaline, showed lower production of dry matter and lower concentrations of Fe, Mn, Zn, N and P. Pine needle mulch + soil, soil + rice husks, acácia bark + soil and the substrate Plantmax® with or without perlita g were the most suitable r for the production of blueberry seedlings, cultivar 'Georgiagem'.

A propagação da amoreira-preta pode ser feita através de estacas de raiz, lenhosas ou herbáceas, ou através de técnicas de cultura de tecidos. Entretanto, pouco se sabe sobre o crescimento e desenvolvimento inicial de mudas micropropagadas de amoreira-preta. Sendo assim, o objetivo deste trabalho foi avaliar o desenvolvimento inicial de plantas micropropagadas de amoreira-preta, previamente aclimatizadas, provenientes do laboratório de cultura de tecidos da Embrapa Clima Temperado, Pelotas-RS. O tratamento avaliado foi o fator cultivar, sendo Guarani, Tupy, Xavante e Seleções avançadas 6 e 12, com quatro repetições, sendo cada unidade experimental composta por cinco plantas, 25 plantas por bloco, totalizando 100 plantas. Após 52 dias em casa de vegetação (25-01-2007), as plantas foram retiradas dos sacos de plástico, e tiveram seu sistema radicular lavado e seccionado na altura do colo, sendo avaliadas as variáveis número de folhas altura da parte aérea e comprimento do sistema radicular (cm), medidos do colo ao ápice da maior ramificação e do colo ao ápice da maior raiz, respectivamente e peso da massa fresca e seca da parte aérea e da raiz (g). Nas condições em que o trabalho foi realizado, a seleção 6 e a cultivar Guarani apresentaram, respectivamente, o maior número médio de folhas. O maior comprimento médio da parte aérea das plantas de amoreira-preta foi observado na cultivar Tupy. Não houve diferença significativa para o comprimento médio do sistema radicular bem como para a massa fresca e seca da parte aérea e do sistema radicular entre as cultivares e seleções avançadas de amoreira-preta.to inicial expexpresso em comprimento de haste e, consequentemente, maior vigor durante esta fase, podendo assim ser indicada como material com maiores possibilidades de sucesso para implantação de um pomar de amoreira-preta em comparação aos demais materiais estudados.The blackberry propagation can be done through root cuttings, woody or herbaceous stem cuttings, or through tissue culture techniques. However, little is known about the initial growth and development of micro propagated blackberry seedlings. The aim of this work was to evaluate the initial development of micro propagated blackberry plants, previously acclimatized, obtained from the laboratory of tissue culture of Embrapa Temperate Climate, Pelotas, Brazil. Three cultivars and two thornless advanced selections (Selection 6 and 12) were evaluated in a randomized block design with four replications and five plants per plot. After 52 days in a greenhouse (01/25/2007), the plants were removed from the plastic bags and had their roots washed and sectioned. The following variables were evaluated; number of leaves; shoot length (cm), measured from the top to the button of the largest branch of the colon; root length (cm) measured from the crown to the longest root apex; fresh and dry weight of shoot and root (g). Under the conditions of this experiment, the selection 6 and cultivar Guarani had, respectively, the highest average number of leaves on 01/25/07. The highest average length of the aerial part of the blackberry plants was observed in cultivar Tupy. There was no significant difference on the average length of roots fresh and dry weight of shoots and roots among cultivars and advanced selections of blackberry. Under the conditions of this trial, it can be concluded that cv. Tupy has a higher growth, expressed by cane length. As a result, it has lager vigor during this phase and can be recommended for new blackberries plantings as the cultivar with better chances of success, among all the tested ones, during the present trial.

O objetivo deste trabalho foi avaliar o comportamento fenológico, a produtividade e a qualidade de oito cultivares de mirtilo do grupo rabbiteye (Bluegem, Bluebelle, Powderblue, Florida, Delite, Briteblue, Climax e Woodard), na região de Pelotas, RS. O trabalho foi realizado durante os ciclos produtivos de 2003/2004, 2004/2005 e 2005/2006. As plantas foram dispostas no pomar em blocos varietais aleatórios, com 16 plantas por cultivar, no total de quatro linhas, com duas cultivares por linha. Para a análise das características dos frutos, a média de cada ano de avaliação foi considerada como uma repetição. Foram observadas as datas de início e fim da floração, início e final de colheita, massa, diâmetro longitudinal dos frutos, número de frutos por planta, teor de sólidos solúveis totais, produção média por planta e produtividade estimada por hectare. Não houve diferença entre as cultivares avaliadas quanto às características massa, diâmetro médio de frutos e teores de sólidos solúveis totais. Na região de Pelotas, há viabilidade técnica para o cultivo de mirtilo, cujas cultivares Bluebelle, Briteblue e Bluegem são as mais produtivas.The aim of this work was to evaluate the yield and quality of blueberry cultivars from the rabbiteye group (Bluegem, Bluebelle, Powderblue, Florida, Delite, Briteblue, Climax and Woodard), in Pelotas County, Southern of Rio Grande do Sul State, Brazil, during three growing seasons: 2003/2004, 2004/2005 and 2005/2006. The plants were set in randomized varietal blocks in the orchard, with 16 plants per cultivar, totaling four lines, with two cultivars per line. For statistic analysis of the fruits characteristics, each year of evaluation was considered as one repetition. The characteristics evaluated were the start and the end of flowering, beginning and end of harvest, mass, longitudinal diameter of fruits, number of fruit per plant, content of total soluble solids, average production by plant, and the estimated productivity per hectare. There was no difference among the cultivars evaluated for the characteristics mass, mean diameter of fruits and levels of total soluble solids. In the region of Pelotas, there is technical viability for growing blueberry, whose cultivars Bluebelle, Briteblue and Bluegem are the most productive.

O objetivo do trabalho foi verificar a viabilidade e definir um substrato adequado para o enraizamento de microestaquia e o crescimento de mudas de mirtileiro cultivar Georgiagem. Foram avaliados diferentes substratos para a técnica de microestaquia mantida em condições de microambiente úmido, com temperatura e luz controladas. As microestacas foram acondicionadas em caixas de politereftalato de etileno, durante 48 dias. Os substratos turfa de musgo Sphagnum sp. e as misturas turfa + perlita, turfa + perlita + fibra de coco, turfa + perlita + serragem permitiram a obtenção de maior percentual de enraizamento.

Mudas de mirtilo apresentam crescimento inicial lento e baixo índice de sobrevivência. Dentre os fatores envolvidos na produção de mudas, a qualidade do substrato é um fator de grande importância. O trabalho foi realizado com o objetivo de avaliar o desenvolvimento de mudas de mirtilo, em diferentes composições de substrato, durante os meses de dezembro de 2005 a março de 2006. Foram utilizadas mudas da cultivar Georgiagem, do grupo highbush, oriundas de multiplicação in vitro. Foram utilizados sete diferentes substratos para a formação das mudas: T1 - Plantmax® (100%); T2 - Plantmax® + perlita (1:1); T3 - solo + composto industrial + perlita (1:1:1); T4 - solo + casca de arroz + terra (1:1:2); T5 - solo + composto industrial + vermiculita (1:1:1); T6 - casca de acácia + terra (1:2); T7 - acícula de pínus + terra - (1:2). Foram avaliados: altura das plantas; acúmulo de matéria seca da parte aérea e raiz, e análise química dos substratos. A composição do substrato influenciou no desenvolvimento das mudas de mirtilo. Os melhores resultados foram observados em substratos com pH ácido. Conclui-se que os substratos acícula de pínus + terra, Plantmax®, Plantmax® + perlita e casca de arroz + terra apresentaram melhores resultados.The blueberry presents slow development and low index of survival of the seedlings. Among the factors involved in the production of seedlings, the quality of the substrate is a factor of great importance. The work had as objective evaluates the development of blueberry seedlings in different substrate compositions, during the months of December 2005 to March 2006. It was used seedlings of the cultivar Georgiagem of the highbush group, originated from of multiplication in vitro. Seven different substrates were used for the formation of the seedlings: T1 - Plantmax® (100%); T2 - Plantmax® + Perlita (1: 1); T3 - Soil + industrial compost + Perlita (1: 1 :1); T4 - Soil + rice husks + Soil (1 : 1: 2); T5 - Soil + industrial compost + Vermiculite (1: 1: 1); T6 - Acacia bark + soil (1: 2); T7 - pine needle mulch + soil (1: 2). They were evaluated: height of the plants, accumulation of dried matter of the aerial part and root and chemical analysis of the substrate. The composition of the substrate influenced in the development of the blueberry seedlings. The best results were observed in substrates with acid pH. The substrate pine needle mulch + soil, Plantmax®, Plantmax® + perlita and rice bark + soil presented better results.