Resumo em Inglês:

Abstract We propose a new methodology for multiple imputation when faced with missing data in multi-environmental trials with genotype-by-environment interaction, based on the imputation system developed by Krzanowski that uses the singular value decomposition (SVD) of a matrix. Several different iterative variants are described; differential weights can also be included in each variant to represent the influence of different components of SVD in the imputation process. The methods are compared through a simulation study based on three real data matrices that have values deleted randomly at different percentages, using as measure of overall accuracy a combination of the variance between imputations and their mean square deviations relative to the deleted values. The best results are shown by two of the iterative schemes that use weights belonging to the interval [0.75, 1]. These schemes provide imputations that have higher quality when compared with other multiple imputation methods based on the Krzanowski method.

Resumo em Inglês:

Abstract To identify superior genotypes, 42 progenies of interspecific hybrids between American oil palm and oil palm were evaluated in an area with incidence of bud rot. The following variables were assessed: total bunch yield (TBY), number of bunches (NB) and mean bunch weight (MBW) from the third to the sixth year of cultivation and estimates of genetic parameters obtained by REML/BLUP procedures. High heritability values ​​of the evaluated traits were observed. The gain estimates for TBY were 14.49% for the selection of the five best progenies and 33.36% for the selection of the five best trees, considering multiplication by cloning. A medium correlation was observed between TBY and NB, a high correlation between TBY and MBW and a negative high correlation between NB and MBW. The results indicate a high expectation of gains with selection for TBY.

Resumo em Inglês:

Abstract Tetraploid Brachiaria ruziziensis genotypes which reproduce sexually are essential for the breeding of other species of the Brachiaria genus which reproduce by apomixis. Aiming at studying the available phenotypic and genetic variability in the breeding population of B. ruziziensis, it was estimated the parameters heritability and genetic and phenotypic correlations between the traits associated with flowering, and the traits responsible for forage yield and nutritional quality. Seventeen traits in 1180 individuals from 59 open pollinated families were studied, and the data were analyzed by mixed model methods. Individuals with sparse flowering presented higher breeding values for total dry matter, yield, and total number of panicles per plant than individuals with early or late flowering. Considering breeding population differences on flowering behavior, on individual narrow sense heritability and on genetic correlations between flowering, agronomic quality and nutritional quality traits have to be considered in intrapopulation breeding and in intrapopulational recurrent selection.

Resumo em Inglês:

Abstract The study aims to compare the efficiency of previously used liquid media for coffee, evaluating NAA concentrations in liquid medium and proline in semi-solid medium in the regeneration of somatic embryos and asses concentrations of BA and IAA in the maturation of embryos in temporary immersion bioreactors. For the regeneration of globular embryos from embryogenic aggregates and calli, we tested five concentrations (0.00, 0.25, 0.50, 1.00 and 2.00 mg L-1) of NAA in liquid medium and five concentrations (0.0, 0.5, 1.0, 2.0 and 4.0 g L-1) of proline in semisolid medium. The multiplication of embryogenic aggregates was highest in culture medium MM, reaching a density 7.5 times greater than that of the initial density. NAA promoted a linear increase in embryo regeneration. The medium containing 2.0 mg L-1 BA and 0.0 mg L-1 IAA yielded the highest percentage of large cotyledonary embryos.

Resumo em Inglês:

Abstract Peanut (Arachis hypogaea) is an important legume and oilseed crop, native to South America and grown in all tropical and temperate regions of the world. A simplified and rapid direct gene delivery system in peanut was developed by vortexing silicon carbide whiskers with callus and with plasmid harboring chitinase and hygromcin genes. The effects of callus age and whisker quantity on transformation efficiency were evaluated. Transformation efficiency (6.88%) was highest when 200 mg of whiskers were used with 5 µg plasmid for 2 g of 20-day-old callus. Hygromcin-resistant calli were regenerated to complete plants which produced seeds normally. Transgene insertion and number of transgene copieswere confirmed by PCR and southern blot analyses, respectively. Transgene expression was evaluated by a pathogenecity test and RT-PCR analysis. In transgenic events, the resistance level to leaf spot disease was far higher than in control plants.

Resumo em Inglês:

Abstract The objective of this study was to estimate genetic parameters for agronomic traits and nutritional value in intraspecific hybrids of B. decumbens. For this, a population of 1,415 hybrids was evaluated in field plots at Embrapa Beef Cattle in Campo Grande/MS/Brazil, with seven clippings in order to estimate field green weight (FGW); total dry matter (TDM); speed of regrowth (SR); tiller regrowth density (TRD); regrowth ability (REG); crude protein (CP); in vitro organic matter digestibility (IVD); neutral detergent fiber (NDF) and lignin (LIG). The statistical analyses were carried out using the mixed models methods. Genetic variability for all traits assessed was detected, and estimates of individual heritability were of medium to high magnitude, indicating the possibility of gains with selection. Significant genetic correlations were observed between FGW and TDM (0.99), TDM and SR (0.81), TDM and IVD (-0.71), TDM and LIG (0.71), and CP and IVD (0.70).

Resumo em Inglês:

Abstract This study aimed to evaluate the effect of recurrent selection on the genetic variability of UENF-14 population after six selections. Two hundred and ten half-sib families were evaluated in two environments in the state of Rio de Janeiro, using incomplete randomized blocks design with treatments arranged in replication within "Sets". There was significant effect for Families within the "Set" (F)/S, proving that there is enough genetic variability to be exploited in the popcorn breeding program of UENF. The significance for the source of variation Environment (E) shows that the environments were distinct enough to promote differences between the evaluated characteristics. It was found that for both characteristics of greatest interest, GY and PE, the magnitude of the additive variance remains with close values in advanced cycles of UENF-14 population, indicating that variability remains, with no evidence of decreases in advanced cycles. This is concluded by the longevity of UENF breeding program.

Resumo em Inglês:

Abstract The objective of this study was to estimate the genetic variability of a Brazilian cultivar of crambe, as well as to estimate the genetic gain, with selection focusing on grain yield in crambe. Eighty two progenies were selected within the FMS Brilhante cultivar in 2009. The progenies were evaluated in 2010 and 2011 in Botucatu and São Manuel, Sao Paulo State, with the FMS Brilhante used as control. Great genetic variability was verified in all of the characteristics studied. Significant interactions of progenies x location and progenies x year were observed based on the joint analysis. The genetic gain for the grain yield ranged from 9.3 to 48.9% on the individual analysis and ranged from 6.6 to 21.4% on the joint analysis. The selection used in the base plant population of FMS Brilhante was efficient to increase grain yield in crambe.

Resumo em Inglês:

Abstract The known sources of resistance to witches' broom (WB), a severe disease of cacao, are limited. Aiming to identify families and parents resistant to Moniliophthora perniciosa, a population of 22 families was evaluated by assessing the number of brooms formed per tree during 10 years under field conditions. The population was established in randomized blocks with three replications of 12 plants each. Significant differences were observed among families. The most outstanding families were NA33 x RB39 and RB39 x P4B, which presented the lowest WB incidence during 10 years. The increase in natural field infection of Scavina clones families and their descendants were clearly demonstrated after 2006. The existence of additive effects for resistance appears clearly for families, which had other source of resistance associated with Scavina. Clones RB39, RB36, P4B, NA33 and CSUL3 are promising parents for pyramiding resistance genes and increasing the stability and durability of resistance to WB.

Resumo em Inglês:

Abstract The objective of this study was to evaluate the performance of Geneva(r) apple rootstocks for 'Gala'. The experiment was set in a complete randomized block design with four replications of tree plants per plot. It was used ten Geneva(r) rootstocks and M.9EMLA and M.7EMLA as controls. It was evaluated plant vigor, annual yield, cumulative yield, cumulative yield efficiency and fruit weight. For 'Gala' vigor control, G.10 and G.757 were more efficient than M.9EMLA; CG.2022 was equivalent and the other rootstocks were less efficient. 'G.24', 'G.969', 'G.30' and 'G.210' presented vigor equivalent to 'M.7EMLA'. 'G.896' was the most vigorous. Among dwarfing rootstocks, G.213 and G.757 were the most efficient on cumulative yield, the last showing the highest cumulative yield efficiency. Among semi-dwarfing, G.210 showed the highest cumulative yield and the highest cumulative yield efficiency. 'G.896' induced higher cumulative yield than 'M.7EMLA'. The greatest 'Gala' fruit weight was on 'G.213' and 'CG.2022'.

Resumo em Inglês:

Abstract The host status of eighteen progenies (CRP 01-12 to CRP 16-12, CRP 19-12 and CRP 20-12) and two cultivars (FB 200 Yellow Master and FB 300 Araguari) of yellow passion fruit to Meloidogyne incognita race 2 was evaluated in a greenhouse experiment. The height and the biomass of the plants, besides the numbers of galls, eggs and second-stage juveniles in roots and soil were assessed after 70 days of cultivation of the genotypes and tomato (control) in plastic pots with 2 kg of soil infested with 5,000 eggs of the nematode. The reproduction factor of the pathogen (RF = Final population/Initial population) was calculated for classifying the genotypes as immune (RF = 0), resistant (RF < 1) or susceptible (RF ≥ 1). The cultivar FB 200 is resistant to M. incognita race 2 and can be cultivated in areas infested with this nematode.

Resumo em Inglês:

Abstract The new sudangrass cultivar [Sorghum sudanense (Piper) Stapf.] was developed by the method of selection of individual plants with progeny testing. The most important traits are high biomass yield with high grain yield.

Resumo em Inglês:

Abstract BRS Ártico is a common bean cultivar with white grains with international standard size (62 g per 100 seeds), appropriate for cultivation in the Central region of Brazil and the state of Paraná. The cycle is semi-early, the yield potential 2677 kg ha-1 and BRS Ártico has moderate resistance to rust and curtobacterium wilt.