RESUMO -Uma das ameaças ao cerrado é a exploração de certas espécies nativas, que tem sido feita de forma extrativista e muitas vezes predatória, tornando-se imprescindíveis ações no sentido de se fazer o cultivo e domesticação destas espécies. Dentre as inúmeras frutíferas nativas que possuem alto potencial para exploração comercial, destaca-se a gabirobeira, que se encontra sob forte pressão devido ao impacto causado pela fragmentação das suas populações, seja pelo extrativismo inadequado, ou pela expansão das fronteiras agrícolas. O objetivo deste trabalho foi avaliar o uso de ácido indolbutírico na sobrevivência, brotação e enraizamento de estacas de gabirobeira. Foram coletadas estacas lenhosas de gabirobeiras da coleção do banco de germoplasma de Campomanesia spp. da UFG-Regional Jataí. Utilizaram-se estacas das espécies Campomanesia adamantium e Campomanesia pubescens segmentadas em ramos de 15 cm de comprimento contendo um par de folhas na parte apical e selecionadas as estacas que apresentavam diâmetro médio de 2,8 6 ± 1,29 cm. O experimento foi conduzido em delineamento inteiramente casualizado para cada espécie em estudo com 5 tratamentos e 4 repetições com 8 estacas/parcela. Os tratamentos foram compostos por 0, 800, 1600, 2400 e 3200 mg/L de Ácido indolbutírico (AIB). As estacas foram tratadas nas doses de Ácido indolbutírico (AIB), com 15 segundos de imersão. Após tratamento com AIB as estacas foram plantadas em bandejas de isopor com as bases perfuradas contendo como substrato areia lavada. Durante todo o período experimental foi utilizado o sistema de nebulização intermitente. Sessenta dias após a instalação do experimento as estacas foram avaliadas, quanto a Brotação, sobrevivência das estacas, porcentagem de enraizamento e porcentagem de calejamento. O uso de AIB em estacas de gabirobeiras proporcionou maior percentagem de brotação bem como maior sobrevivência das estacas, porém não proveu enraizamento.Palavras-chave: Campomanesia adamantium, Campomanesia pubescens, cerrado, fruteira nativa, propagação. GABIROBEIRAS PROPAGATION BY CUTTING THE ASSOCIATED INDOLBUTYRIC ACID

The objective of this work was to define the most suitable selective strategy for the simultaneous increment of yield components of green maize, by comparing three selection indexes weighted by economic weights and by the REML/BLUP method, in the assessment of predicted genetic gains for traits of interest. An experiment with 75 topcross hybrids from partially inbred S1 lines of green maize was carried out in Jataí, in the state of Goiás, Brazil, using a randomized complete block design, with four replicates. The following yield traits were evaluated: straw ears and commercial ears, grain mass, ear length, ear diameter, and number of ear rows. The selection indexes of Smith and Hazel, Williams, and Mulamba & Mock were applied and weighted for four economic weights (1, CVg, CVg/CVe, and h2). Among the tested selection indexes, those of Williams and Mulamba & Mock are the best-fit ones for the selection of topcross hybrids of green maize, as they provide positive and more balanced selection gains for all evaluated traits. The REML/BLUP method shows better predicted genetic gains than those achieved by the three selection indexes, besides being efficient for the selection of topcross hybrids of green maize.

Information on the effect of endogamy and combining ability of inbred families is essential in hybrid maize (Zea mays L.) breeding programs. The objective of this study was to evaluate the effect of inbreeding in a maize population and the performance of top-cross hybrids from this population, with a broad genetic base tester. First, 110 S1 families were generated and established in the field along with families from the original population. The experiment was arranged in a randomized block design with three replicates, in 3.0 m plots with 15 plants. Traits of agronomic importance, inbreeding depression, and the general effect of dominance deviations were estimated the first stage. In the second stage, 69 inbred families (S2) with low inbreeding depression were evaluated by top-cross tests using the F2 generation of the commercial hybrid AG 6040 as tester. The same traits from the first stage were evaluated. Inbreeding depression in the first stage was higher for traits related to production, which indicates that the heterozygous loci contribute more to these traits, with the additive effects being less important. In the second stage, the best estimates of the general combining ability (GCA) for grain weight were found in progenies 51, 33, 17, 9, 3, and 67, showing good performance and good potential for use in breeding programs.

Entre as fruteiras nativas do cerrado com potencial para exploração comercial, destaca-se o cajuzinhodo-cerrado. O objetivo deste trabalho foi avaliar o comportamento do florescimento e a diversidade genéticade cajuzinho-do-cerrado proveniente de sete municípios do Cerrado Goiano. O trabalho foi conduzido dentro da coleção Biológica “ex situ” de Anacardium humile A. St. Hil, na área de recursos genéticos da UFG Regional Jataí, que contém 640 plantas provenientes de 14 municípios. Dentro desta coleção, foram avaliados acessos gerados de planta-mãe com sementes advindas de sete municípios (Caiapônia, Chapadão do Céu, Itarumã, Jataí, Mineiros, Portelândia e Serranópolis). Entre os meses de julho e agosto de 2016 cada acesso foi avaliadoquanto às características de florescimento: número de plantas em pleno florescimento e os resultados expressos em %; número de flores por cada acesso de cada município, através de contagem direta; comprimento médio da flor e largura da flor; número de ramificações através de contagem direta. Os resultados foram submetidosà análise descritiva, obtendo-se média, mínimo, máximo, coeficiente de variação e importância relativa dos caracteres para variação total. Foi utilizada, também, à análise multivariada estimando-se a distância euclidiana média obtida a partir dos sete ambientes de coleta de cajuzinho-do-cerrado, avaliados com base nos atributosdo florescimento analisados. A medida de similaridade e agrupamento dos ambientes de coleta foi feita pelo algoritmo de otimização de Tocher e dendrograma UPGMA. Plantas dos municípios Itarumã, Serranópolise Portelândia apresentaram maior percentual de florescimento. Para número de flores por município maior destaque foi observado para Serranópolis, Jataí e Itarumã. Existe variabilidade genética entre os acessos estudados, mesmo em áreas próximas, constatou-se existência de considerável diversidade o que possibilita indicar acessosmais promissores para ambientes agricultáveis e que apresentam maior precocidade.

The purpose of this study was to select top cross hybrids of green maize for yield, derived from partially inbred S1 lines based on genetic values using the REML/Blup method, and to estimate important genetic parameters for green maize breeding programs. The experiment was conducted in an experimental area located between 17º53´ S and 52º43´ W, 680 m altitude. The evaluation of 75 top cross hybrids was performed in a randomized block design with four replicates. A sample of five plants/ears was used in each plot to evaluate grain mass trait (MASS). For commercial ear yield trait (CEYIELD), evaluations were carried out for the total number of plants per plot. Hybrids were selected via BLUP procedures using the Selegen-REML/Blup program. Based on the Restricted Maximum Likelihood (REML), we estimated the coefficients of genetic and residual variation and components of variance, by which a genetic variability between the top cross hybrids was observed. This shows the possibility of successful selection for the traits under evaluation. The estimated accuracy for the selection of top cross hybrids was 0.81 for commercial ear yield and 0.64 for grain mass, pointing to high and moderate precision levels for CEYIELD and MASS traits, respectively, corroborating the possibility of success in selecting top cross hybrids based on the CEYIELD trait. The predicted genetic gain from the selection was 20.12%, for CEYIELD, and 6.10%, for MASS. Therefore, the REML/Blup statistical tool was efficient in selecting top cross hybrids of green maize, providing significant genetic gains for the traits under evaluation. There was evidence that hybrids 19 and 48 were distinguished from others because of the high genetic effects obtained for the commercial ear yield and grain mass weight.

In plant breeding programs, the selection of potential progenies in early generations of inbreeding is an essential step. Considering that, the adoption of topcrosses helps the breeder in the selection, this study aimed to verify the potential of S 2 strains for synthesis of synthetic varieties and to obtain experimental information on yield and agronomic potential of topcross hybrids. As such, 75 topcross hybrids were generated from crossing 75 S 2 lines with F 2 generation of the commercial hybrid. The 75 hybrids were grown in a field, along with two commercial hybrids in a randomized complete block design with 4 replicates and in 4-meter plots. Flowering, plant height, height, diameter, length and weight in the ear, and grain yield traits were examined. Analysis of variance was performed, the combining ability was estimated, and, from the means, the Scott & Knott test was conducted. So, the topcross hybrids that distinguished themselves for grain yield were those composed by lines 67, 14, 44, and 69, presenting high CGA, therefore indicating good potential for producing synthetic or base population. For the other traits of agronomic interest that were assessed in maize, a potential for selection with different focuses was found: reduction of cycle and height and increase in length and diameter of the ear.

The present study selected progenies, aiming at the production of green corn, by methods of intrapopulation recurrent selection with subsequent recombination, generating open-pollinated populations. To this end, in the 2017/2018 second season, progenies from the PMVJ01 population (originated from the recombination of progenies of the TG-02R2 x AG1051 cross) were evaluated, using PMVJ01 and the hybrid AG1051 as controls. The following parameters were evaluated: flowering, heights, green ear yield, husk cover, ear diameter and length, mass yield, ear shape, number of rows on the ear, alignment of rows, color of kernels, and husk width and length. Genetic parameters were estimated, and the gain was predicted with the selection of 20% of the progenies, using the index of Mulamba and Mock in four selection procedures and a fifth by multivariate method. Genetic variability was found in the population, which allows advances in the selection process. After recombination, two of the populations generated showed potential for use as open-pollinated cultivar.

Selecting potential progenies in early inbred generations is an essential step towards the success of breeding programs. Given this, the use of top crosses assists breeders in selecting progenies to generate lines with the potential for hybrid yield. Thus, the purpose of this study was to assess the behavior of partially inbred progenies (S1) of maize with potential for green maize yield in top crosses and to evaluate the hybrid performance. Seventy-five top cross hybrids were generated from the cross between 75 S1 progenies and the F2 generation of the hybrid AG 1051. The 75 hybrids, the male tester (F2 generation of the hybrid AG 1051 as a broad genetic base tester), and the hybrid AG 1051 were sown in a block design with four replicates. The following traits were evaluated: husked ear yield; commercial ear yield; flowering; plant height; strawing; mean weight of grain mass in green maize stage; tassel branch number; ear row number; ear length; and ear diameter. The analysis of variance was performed estimating the general combining ability, and, from the means, the Scott & Knott test was conducted. The top cross hybrids that were prominent for commercial ear yield were those composed of partially inbred progenies 19, 48, 6, 28, and 42 with high GCA, suggesting a potential for the production of open pollination population or synthetic production as well.