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Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The peach is a traditional crop in the south of Rio Grande do Sul State, Brazil, where 35 million to 50 million cans of peaches in syrup are produced annually. All the raw materials for the peach canneries come from cultivars originated from the peach breeding program of the Brazilian Agricultural Research Corporation (Embrapa Temperate Agriculture), which started before the establishment of Embrapa at the Experimental Station of Pelotas, then managed by the Ministry of Agriculture. The objective of this study was to estimate the genetic progress in phenological and production traits of canning peach resulting from the peach breeding program of Embrapa Temperate Agriculture over 53 years. We divided the data records considered in the estimation of genetic progress into two periods, 1964–1984 and 1985–2017. The following traits were evaluated: days to maturity, fruit development period, number of fruits, fruit weight, fruit yield, and soluble solids content. Genetic gain was observed for early maturation, shorter fruit development period, and increased fruit yield. [ABSTRACT FROM AUTHOR]

Rice is one of the most consumed cereals in the world and of extreme social and economic importance in Brazil. Minas Gerais is the leading State in irrigated rice production in the Southeast Region. This study aimed to estimate the genetic progress of 26 years of the irrigated rice breeding programme of Epamig in Southeast Brazil by time meta‐analysis. Genetic progress was estimated for grain yield, plant height and days to flowering. The dataset understood 162 genotypes in 91 trials of value for cultivation and use of 26 seasons. The rate of annual genetic gain for grain yield was estimated.99% (49.85 kg year−1). It was also verified that was a reduction in plant height and an increase in days to flowering, even if very low. Due to distinct historical phases of the rice breeding programme, there were changes in research focus and, consequently, affected the genetic gains. With this study, it was possible to evaluate the selection strategies carried out in the past and identify important points to maintain. [ABSTRACT FROM AUTHOR]

Most studies assessing the genetic progress in soybean have traditionally focused on retrospectives approaches, where commercial genotypes released over an extended period are tested in a limited number of environments. In this context, multi-environment trials (METs) from a soybean breeding program constitute an interesting approach to complement previous studies. This study aims to quantify the rate of genetic progress in soybean genotypes developed by the private seed company Grupo Don Mario in Argentina and Brazil. Our objective was to estimate breeding effects on yield and yield stability across maturity groups (MGs) and to analyze how these effects have been affected across yield environments. We studied 124 soybean genotypes from MGs IV to VIII in 2015 METs. Genotypes were released from 2005 onwards in Argentina and from 2010 onwards in Brazil. To assess breeding effects, genotype seed yield best linear unbiased predictor (BLUP), yield stability, and the genotype BLUP in low, medium, and high yielding environments were regressed to the year of release. Seed yield genetic progress was evident for all MGs and ranged from 20.5 to 46.1 kg ha−1 yr−1 in Argentina and from 23.2 to 53.6 kg ha−1 yr−1 in Brazil. Moreover, no changes were observed for yield stability during recent years. When dissecting the genetic progress by targeted environment yield, the rate in Argentina was 41.4, 23.6, and 16.6 kg ha−1 yr−1 in the high, medium, and low yielding environment, with relative rates of 0.9%, 0.6% and 0.6% yr−1, respectively. In Brazil, the rate was 43.0, 40.5, and 17.8 kg ha−1 yr−1 in the high, medium, and low yielding environment, with relative rates of 0.9%, 1.0% and 0.5% yr−1, respectively. Absolute and relative rates increased from low to high environmental quality. However, the rate varied across MGs and environmental yield. Our study revealed that, while genetic progress was evident for MG IV to VII in Argentina and for MG V to VIII in Brazil, most genotypes did not change their response to improvements in environmental quality during the early 21st century. Moreover, the rate of progress depended on the interaction between MGs and environmental yield. This study complements retrospective estimates of soybean genetic progress by evaluating a broader range of environments and MGs. Future research should focus on exploring the physiological and/or environmental factors behind the different rate of progress across MGs and yield environments. • Soybean genetic progress was estimated using multi-environment trials from a breeding program. • During the early 21st century, soybean yields increased without changes in yield stability. • Absolute and relative genetic progress rates increased from low to high environmental quality. • Genetic progress rate varied with environmental yield and maturity groups. [ABSTRACT FROM AUTHOR]

The importance of rice (Oryza sativa) is indisputable this cereal is the staple food for half of the global population. Genetic progress estimation allows evaluation of the effectiveness of genetic improvement of crops and helps in the planning of breeding programs. This paper aims to estimate the genetic yield progress made by the program in the state of Minas Gerais, Brazil, which is run by the Epamig/UFV/Embrapa consortium. A total of 210 lines were evaluated by value for cultivation and use testing that was conducted in the municipalities of Janaúba, Leopoldina, and Lambari, from 1993 to 2016. Based on Vencovsky's (1986) method, the genetic gains in Lambari, Janaúba, and Leopoldina were 1.46, 0.14, and 0.11%, respectively. The gain in Leopoldina was considered very low during the evaluated period. According to Breseghello's (1998) method, the annual average genetic gain was 0.23 and 0.04% in Lambari and Janaúba, respectively. In Leopoldina, a yield gain of - 2.37% per year was observed for the evaluation period from 1994 to 1999, and a yield gain of 0.1% per year was observed from 2000 to 2016. These results can be explained by the focus on quality as a strategy for the breeding program in Minas Gerais State in the 1990s. Vencovsky's (1986) and Breseghello's (1998) methods were able to quantify yield gains and demonstrate the dynamics of the irrigated rice genetic improvement program in Minas Gerais State. [ABSTRACT FROM AUTHOR]

The objective of the present study was to promote a better understanding of the rubber yield of young progenies of Hevea brasiliensis evaluating the stability and the repeatability of early rubber yield test employed in a genetic breeding programme. The genetic material consisted of 30 open pollination progenies evaluated in the Colina county, São Paulo state, Brazil, in a randomised block design. Rubber yield was evaluated by the Hamaker Morris-Mann early rubber yield test in 5-year-old plants and the modified Hamaker Morris-Mann test in 3- and 4-year-old plants. The mixed linear model procedure Reml/Blup (Restricted Maximum Likelihood/Best Linear Unbiased Prediction) was used in the statistical analyses. The progeny effect was significant and indicated favourable conditions for selection. The rubber yield trait was highly influenced by the environmental conditions in the different measurements. The predicted genetic gains indicated favourable conditions for selection. The repeatability coefficient ( p ^ = 0.42) showed a moderate capacity of the genotypes to repeat the expression of the trait in the same manner from one measurement to another. Selection made on the criterion of temporal stability for early rubber yield coincided better with progenies selection in the fifth year than with selection in the third year. The predicted genetic gains indicated favourable condition for progenies selection using early yield tests at different ages. Early selection of high yield progenies in the third year, selects partially promising progenies. Therefore, when early selection is made in the third year, selection in the following years is recommended. [ABSTRACT FROM AUTHOR]

The search for alternative energy sources has grown recently. Surely, elephant grass (Pennisetum purpureum Schum.) is a tropical grass of increased efficiency in the use of light and presents a high production of biomass, being cost-effective for direct combustion and charcoal obtainment. This study aimed to select the best families and individuals in full-sibling families of elephant grass by estimation of genetic parameters and prediction of genetic values by methods of restricted maximum likelihood (REML) and best linear unbiased prediction (BLUP), respectively, as an alternative of energy easy for Brazil. One hundred twenty progenies of full-siblings from bi-parental crossings were assessed in two harvests and one environment. The experimental design was a randomized block design with five-plant per plots and three replications. The assessed traits were dry matter production, tiller number, plant height, stem diameter, and neutral detergent fiber. For all traits, accuracy showed values above 90% and heritability of family means between 0.81 and 0.92%. Families 3, 1, and 2 were the best ranked, being the most indicated for selection. The REML/BLUP method proved to be suitable for selecting individuals of elephant grass for energetic purposes. • The search for alternative energy sources has grown recently. • Pennisetum purpureum is a potential energy source crop in Brazil. • Families 3, 1 e 2, respective, present the highest potential biomass. • The RELM ∖ BLUP method is a suitable to select elephant grass genotypes. [ABSTRACT FROM AUTHOR]

Maize breeding programs conduct multi-environment trials every year to assess the performance of new cultivars in pre-releasing tests. The data are combined across sites and seasons to perform a joint analysis in order to obtain information that will help breeders to select the best cultivars for different environments. Beyond this, it is essential to understand the different factors that can hamper the selection and genetic progress (i.e., genetic variability, selection intensity and genotype-byenvironment interactions). In this study, the genetic progress (GP) was estimated and the adaptability and stability of 81 maize genotypes were evaluated in a series of trials for the value of cultivation and use (VCU) between the 2010/11 and 2014/15 growing seasons. The genotypes were composed of openpollinated varieties, topcross hybrids, intervarietal hybrids, and single, double and three-way cross hybrids and were assessed in 117 environments in the central region of Brazil, from which 22 presented environmental stresses. For grain yield, an annual GP of 331.5 kg ha-1 was observed, thus showing efficiency in the selection of superior cultivars. Additionally, it was observed that some low-cost seed cultivars showed yield potential, adaptability and stability estimates that were compatible with commercial hybrids, thus making them quite attractive for cultivation in environments with or without abiotic stresses. [ABSTRACT FROM AUTHOR]

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to characterize physiologically wheat cultivars released in different decades and identify selection criteria for the continued genetic progress in Brazil. Ten cultivars released from 1940 up to 2009 were tested during 2010 and 2011 crop seasons. The following traits were evaluated: grain yield (GY), thousand-kernel weight (TKW), grain number per m −2 (GN), plant height (PH), harvest index (HI), above-ground biomass (BIO), relative Chlorophyll content and leaf gas exchanges. The increase in grain yield was 29 kg ha −1 yr −1 a genetic gain of 0.92%, annually. Grain yield improvement was largely associated with HI (0.94 ** ), number of grains m −2 (0.93 ** ), BIO (0.88 ** ) and reduced PH (−0.93 ** ). The post-anthesis Chlorophyll content, stomatal conductance and pre/post-anthesis photosynthetic rate were positively correlated with GY. Genetic gains of Brazilian wheat are mainly related to the increases of HI, GN, and BIO. These improvements were achieved by reducing PH and raising gas exchanges and chlorophyll content. [ABSTRACT FROM AUTHOR]

Highlights: [•] Study with 22 rubber tree progenies in three regions of São Paulo state, Brazil. [•] Comparing the genetic gains methods, it is possible to choose one that maximize the genetic progress, this could reduce the selection cycle of the species. [•] MEI method shows high genetic gain values for early selection in rubber tree progenies. [•] With the study this 22 progenies is possible reduce the selection cycle of rubber tree. [ABSTRACT FROM AUTHOR]

Root-knot nematodes (Meloidogyne spp.) are one of the major pests of agricultural crops worldwide. In Brazil, these nematodes are widely distributed in melon fields, and there are no reports of resistant melon cultivars. This study aimed to estimate genetic variance components for the selection of melon genotypes resistant to Meloidogyne incognita , M. javanica , and M. enterolobii. Two experiments were carried out in a completely randomized design, the first with 14 replications and the second with 10 replications, in a factorial design. Thirteen melon genotypes were tested. In both experiments, the total number of eggs and juveniles (TNEJ) was estimated and used to determine the reproduction factor (RF) and reproduction index (RI) of nematodes. Melon genotypes showed wide genetic variability in resistance to the three nematode species, resulting in high estimates of heritability (92%) and accuracy (96%). Such findings indicate the possibility of genetic gains with selection. Melon AC-09, PI157082, and 'Ouro' were found to be sources of resistance to M. incognita , M. javanica , and M. enterolobii , respectively. [Display omitted] • Thirteen genotypes were tested against M. incognita , M. enterolobii and M. javanica. • Genetic parameters were estimated using the REML/BLUP methodology. • Genotypes AC-09, PI157082, and 'Ouro' are resistant to at least one Meloidogyne sp. • The genotypes can be sources of resistance for plant breeding programs. [ABSTRACT FROM AUTHOR]

Abstract: Milk production in tropical environments requires the use of crossbreeding systems including breeds well adapted to harsh conditions, but with lower productivities when compared to specialized breeds. Besides the genetic improvement for milk production, lactation lengths also need to be studied for most of these breeds. Accordingly, genetic parameters were estimated for 305-day cumulative milk yield (MY305), test-day milk yield (TDMY), and lactation length (LL) using information from the first lactations of 2816 Guzerat cows selected for milk production in 28 herds in Brazil. Contemporary groups were defined as herd, year and season of the test for TDMY, and as herd, year and season of calving for MY305 and LL. Variance components were estimated with the restricted maximum likelihood method under a multi-trait animal model. Heritabilities estimated for TDMY ranged from 0.16 to 0.24, and were 0.24 and 0.12 for MY305 and LL, respectively. Genetic correlations were high and positive, ranging from 0.51 to 0.99 among TDMY records, from 0.81 to 0.98 between each TDMY and MY305, and from 0.71 to 0.94 between each TDMY and LL. Genetic parameters obtained in this study indicated the possibility of using test-day records for the prediction of breeding values for milk yield in this population of the Guzerat breed. The use of TDMY as selection criteria would result in indirect gains in MY305 and LL. However, the highest response to selection for MY305 would be obtained by direct selection for this trait. [Copyright &y& Elsevier]

Copyright of Ciência Animal Brasileira is the property of Universidade Federal de Goias, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Saúde e Produção Animal (RBSPA) is the property of Revista Brasileira de Saude e Producao Animal (RBSPA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract - The study aimed to estimate parameters, values and genetic gain for growth traits in progenies of Eucalyptus camaldulensis, in the State of Mato Grosso. The progenies test was conducted under a randomized block design with 132 progenies, five replications and three plants in single rows, spaced 3 m x 2 m in Santo Antonio do Leverger, MT. At 24 months of age, progenies were evaluated for the characters: a) diameter at base height (DBH), in centimeters, b) total height, in meters, c) survival. The individual in the narrow sense heritability for the traits studied can be considered medium to high magnitude (0.13 and 0.21) for height and diameter, respectively. The heritability for survival were practically nil, due to low genetic variability among the progenies, as evidenced by high survival rate of the plants (96.8%). The phenotypic and genetic correlations were of high magnitude for DBH and height prediction. There is genetic variation among progenies for growth traits which will provide significant genetic gains with selection. [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate the genetic parameters of the IPR 114 maize commercial variety for breeding purpose and the efficiency of the method. It was perfomed two cycles of half-sib progenie, between 2004 and 2007. The progenies were evaluated in a randomized complete block desing with two replications per environments and the plots were composed of one 4 m length row spaced on 0.8 m, and five plants per meter. The trials were carried out in Londrina and Ponta Grossa, Paraná State, Brazil. There were evaluated 173 and 154 progenies for selection cycles 1 and 2, respectively, analyzing the following traits: plant height, ear height, days to flower, prolificacy and predict grain yield. In both cycles verified significant genetic variability between progenies. Significant selection gains were obtained for predict grain yield, showing 6.33 and 5.03% for cycles 1 and 2, respectively. The estimative for genetic parameters obtained in this work justify the selection program continuity of the IPR 114 maize population [ABSTRACT FROM AUTHOR]

Copyright of Revista Agro@mbiente On-line is the property of Revista Agro@mbiente On-line and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The significant increase in maize production in the second season crop in Brazil, mainly in central-south of the country have stimulated breeding programs to select genotypes adapted to the climatic conditions of different sowing times. The objective of this study was to quantify the progenies x sowing times interaction and check its reflexes on the genetic progress with the use of multivariate selection for selection progenies of the maize Composite Isanão VF-1. Sowings were done in the second growing season, in 2004 and in first growing season of the 2004/05 crop year. A total of 71 half-sib progenies were evaluated in a randomized block design with three replications. The traits evaluated were: plant height, ear height, lodged and broken plants, prolificacy and grain yield. There was decomposition of progenies x sowing times interaction and gains from selection index Mulamba and Mock were estimated. There was a predominance of the simple interaction for most traits, except prolificacy, which revealed 86% of complex type interaction. For the index Mulamba and Mock, proportional gains most appropriate for the traits set was obtained by the economic weights assigned by attempts. The predicted gains were 1.41, 0.86, -13.03, 9.54 and 16.12% for plant height, ear height, lodged and broken plants, prolificacy and grain yield, respectively. [ABSTRACT FROM AUTHOR]

• Economic values are widely used in the development of breeding objectives. • In Brazil the use of economic selection indexes in beef cattle is rare. • An economic value is the value of a one unit change in an individual trait, while keeping all other constant. • Economic values of six characteristics of production, reproduction, maternal and carcass quality were calculated. • The simulated production systems represent the systems used in a region of high production of beef cattle in Brazil. • This study will make it possible to implement the selection indexes in systems similar to those used here. The aim of this study was to develop selection indices for Nellore cattle raised in two complete cycle production systems in the Brazilian Cerrado, with Tropical climate, where bulls are mated with heifers and mature cows. The resulting offspring are retained as replacements or sold at 2 years. In System 1 (S1), the animals were raised and finished on pasture, while in System 2 (S2), the animals were raised on pasture and males were finished in the feedlot. The economic values were determined by stochastic simulation of the production system using partial derivatives of the profit function, changing one trait at a time, by 1 unit, while keeping the other traits constant. Relative economic values were calculated for cow weight at 5 years, weaning weight, maternal weaning weight, postweaning average daily gain, fat thickness, ribeye area, and stayability. The economic values were, respectively, US$0.67, US$0.41, US$-0.15, US$0.09, US$-0.17, US$187.6 and US$2.7 for S1, and US$0.47, US$0.45, US$-0.004, US$0.28, US$-0.59, US$157.5 and US$0.73 for S2. Consequently, increased profitability can be obtained by improving the cows' ability to stay in the herd, cow weight, ribeye area, weaning weight, and postweaning gain. The accuracy of the indices was 0.85 (S1) and 0.86 (S2). The application of these indices will aid Nellore breeders to select superior animals, facilitating the genetic progress and profit of the herd. [ABSTRACT FROM AUTHOR]

Yield increase in soybean [Glycine max (L.) Merr.] has occurred due to plant breeding, as well as the improvement in management practices. Genetic gain for important traits in soybean due to plant breeding in South Brazil has not been evaluated. The objective of this study was to measure the genetic progress of several soybean agronomic, phenological and physiological traits, in a historical set of cultivars released for cultivation in South Brazil from 1965 to 2011. Twenty-nine cultivars were evaluated in a three replicate randomized complete block design at two locations in the 2016/17 crop season. Mean genetic gain for yield was 40.06 kg ha−1 year−1 averaged across locations. The modern cultivars had higher biological yield (BY), harvest index (HI), number of pods per plant (NPP), and lower number of branches per plant, plant height, and lodging score compared to older releases. There was a reduction in the vegetative period, and increase in ratio between reproductive and vegetative periods (R/V). Photosynthetic rate (PN) and transpiration rate (Tr) also increased with year of release. The traits BY, NPP, HI, R/V, number of seeds per pod, PN, Tr, and chlorophyll content (Chl a and b) was highly associated with seed yield. Breeding strategies that maximize the R/V ratio, and prioritize indirect selection through HI, BY, NPP, PN, Tr, and Chl a and b, will likely contribute to improving soybean yield in the future. [ABSTRACT FROM AUTHOR]