DSpace Coleção: Artigo em periódico indexado (CNPGL)

Structural characteristics and forage biomass accumulation of dwarf elephant grass genotypes at two stubble heights.

Thu, 01 Jan 2026 00:00:00 GMT

Título: Structural characteristics and forage biomass accumulation of dwarf elephant grass genotypes at two stubble heights. Autoria: SILVA, R. B. da; RIBEIRO, K. G.; GOMIDE, C. A. de M.; PACIULLO, D. S. C.; LEDO, F. J. da S.; PAIVA, L. E. F.; SOUZA, E. M. B. de; CECON, P. R. Conteúdo: The objective was to evaluate the structural traits and forage accumulation of elephant grass genotypes under two stubble heights. The experiment was conducted in a factorial scheme, with five genotypes (P 2022 S1, 1810, 2111, 2035 and BRS Kurumi) and two stubble heights (25 and 45 cm), in a randomized block design, with three replications, considering the rainy and dry periods. Forage accumulation of the rainy period was higher for genotype 2111 (P<0.05) compared to P 2022 S1 and BRS Kurumi. The 1810 and 2035 genotypes showed forage accumulation similar to 2111. In the dry period, forage accumulation values were approximately 35% of those observed in the rainy period, with the BRS Kurumi and P 2022 S1 genotypes presenting lower values (P<0.05) compared to the others. The stubble height of 25 cm resulted in lower canopies (82 cm) than that at 45 cm (96 cm). The genotypes P 2022 S1 and 2111 had a higher percentage of leaves and a lower percentage of stem at the stubble height of 45 cm. The genotypes 2111 and 1810 were superior to BRS Kurumi for the percentage of leaf blade and stem at the defoliation height of 45 cm. In the dry season, the genotype 2111 showed the highest leaf-stem ratio. The genotypes 1810, 2111, 2035 and BRS Kurumi showed the highest leaf and lowest stem percentage. The defoliation height of 45 cm resulted in higher forage density. The genotypes 2035, 2111 and 1810 stood out for the high forage accumulation and leaf percentage at both stubble heights during the rainy season. Management with a defoliation height of 45 cm increases the leaf blade percentage and the leaf-stem ratio and reduces the proportion of stem in the forage harvested above the residue.

Diallel analysis of elephantgrass clones for bioenergy production in a tropical environment.

Thu, 01 Jan 2026 00:00:00 GMT

Título: Diallel analysis of elephantgrass clones for bioenergy production in a tropical environment. Autoria: PESSOA, T. de V. de S.; SANTOS, E. de F. dos; CARNEIRO, J. da C.; CARNEIRO, P. C. S.; DIAS, K. O. das G.; MACHADO, J. C. Conteúdo: Climate change caused by fossil fuels has driven the search for bioenergy sources. Elephantgrass [Cenchrus purpureus (Schumach.) Morrone] biomass is a promising alternative for diversifying the energy matrix. One of the main steps of a genetic breeding program is the selection of parents who will form the crossing block, and the use of diallel analysis is critical in this step. Therefore, this study aimed to use mixed linear models to analyze diallel crosses and estimate the general combining ability (GCA) and specific combining ability (SCA) of elephantgrass clones to select superior parents and hybrids for bioenergetic applications. Eleven parents were crossed in a diallel scheme, totaling 55 hybrid combinations, and evaluated in a randomized complete block design with three replications. The measured traits were dry biomass production (DBP), in vitro dry matter digestibility (IVDMD), and cellulose-lignin (C:L) ratio. There was a significant effect of SCA, SCA × cut interaction, and permanent effect on DBP, and a significant effect of GCA on IVDMD and C:L. There was a predominance of genes with additive effects controlling IVDMD and C:L traits, and dominance and epistasis for DBP. The parents selected for biochemical conversion processes were Embrapa’s Active Germplasm Bank of Elephantgrass (BAGCE) 38 and CNPGL 92-38-2. The parents selected for direct combustion of biomass were BRS Canará, BRS Capiaçu, and CNPGL 96-27-3. The hybrids BAGCE 21 × BAGCE 38, BAGCE 30 × CNPGL-92-38-2, and BAGCE 38 × BRS Kurumi show potential for the production of dry biomass.

Genomic variants associated with oocyte and embryo production in dairy Gir cattle.

Thu, 01 Jan 2026 00:00:00 GMT

Título: Genomic variants associated with oocyte and embryo production in dairy Gir cattle. Autoria: ROCHA, R. de F. B.; OLIVEIRA, H. C. de; MARTINS, M. F.; MACHADO, M. A.; PANETTO, J. C. do C.; SILVA, M. V. G. B.; GUIMARÃES, S. E. F. Conteúdo: The use of in vitro fertilization protocols associated with genomic selection increases genetic gain in dairy cattle. The aims of this study were to uncover genetic variants in a specific interval on BTA7 and to investigate their effects on the number of oocytes and embryos in dairy Gir. Previous research uncovered a region on chromosome 7 (BTA7) associated with oocyte and embryo production. In the current study, genomic variants were investigated in this region for 12 sires with positive Predicted Transmission Ability for milk production, which are widely used in dairy herds to produce daughters for oocyte and embryo production. Several variants were identified and four variants were classified as lead SNPs. ANOVA was carried out for the daughters' genomic estimated breeding value (GEBV) and phenotypes according to the genotype of the bulls. Two lead SNPs were single-nucleotide substitutions and both resulted in premature stop codons in XRCC4 and HAPLN1 genes. A deletion of five thymines in an intergenic region occurred in the third lead SNP. The fourth lead SNP involves the deletion of one nucleotide in the EDIL3 gene, causing a frameshift. All genotype groups were significantly different for GEBV and some for phenotype. In conclusion, the mutant alleles of each lead SNP were associated with the production of oocytes and embryos in the dairy Gir, leading to a decrease (rs518509552, rs438544900), an increase (rs450555472) when homozygous or a decrease (rs470818992) when heterozygous. Research is underway to investigate the association of such variants with dairy production and environmental resilience traits.

Eficiência de herbicidas na cultura da alfafa em fase de estabelecimento.

Wed, 01 Jan 2003 00:00:00 GMT

Título: Eficiência de herbicidas na cultura da alfafa em fase de estabelecimento. Autoria: SILVA, W. da; VILELA, D.; PEREIRA, A. V.; FERREIRA, R. de P.; COBUCCI, T. Conteúdo: Avaliaram-se a seletividade e a eficiência de herbicidas latifolicidas no controle de plantar daninhas na cultura da alfafa, cultivares Crioula e Pioneer 58 N 58. Os experimentos foram conduzidos na Embrapa Gado de Leite, em Coronel Pacheco, MG, entre fevereiro e junho de 2000. Foi utilizado o delineamento em blocos ao acaso, com dez tratamentos: fomesafen (150 e 225 g ha-1), chlorimuron-ethyl (12,5 e 20 g ha-1), imazethapyr (70 e 100 g ha-1) e MSMA (1.920 e 2.880 g ha-1), duas testemunhas (com e sem capina), e com quatro repetições para cada cultivar. Os produtos foram aplicados 25 dias após a emergência da alfafa e, três dias após, foram aplicados sobre todo o experimento 250 g ha-1 de fluazifop-p-butil. Os herbicidas apresentaram excelente controle das principais plantas daninhas, acima de 91% até os 90 dias após a aplicação, exceto chlorimuron-ethyl na dose de 12,5 g ha-1. As gramíneas Panicum maximum, Digitaria horizontalis, D. insulares e Brachiaria decumbens foram controladas efïcientemente pelo fluazifop-p-butil, na dose única. Imazethapyr não afetou as plantas em nenhuma das doses estudadas. MSMA, chlorimuron-ethyl e fomesafen causaram toxicidade inicial, sem danificar o meristema apical, com boa recuperação das plantas de alfafa de ambos os cultivares. Os herbicidas, nas duas doses, proporcionaram aos cultivares biomassa seca da parte aérea e altura das plantas semelhantes às da testemunha capinada. A interferência das plantas daninhas na testemunha sem capina reduziu a produção de biomassa seca em 75% e proporcionou menor altura de plantas em ambos os cultivares.