Resumo em Inglês:

Abstract In many cases, traditional analysis of breeding trials based on analysis of variance (ANOVA) do not allow a suitable genetic evaluation. Alternatively, mixed model-based approaches create the possibility of dealing with unbalanced data and modeling spatial trends. The aims of this study were to compare the goodness-of-fit of the model and the genotype ranking through different residual modeling approaches and to select the best performing tropical wheat genotypes based on the best-fitting model. A panel of tropical wheat genotypes was evaluated in three field trials conducted between 2020 and 2021 for grain yield. Linear mixed model analyses were used on the data to estimate the genetic parameters and to predict the genotypic values in analyses of single- and multi-environment trials. Accounting for spatial trends in the analyses of single- and multi-environment trials provides better outcomes than the compound symmetry model does.

Resumo em Inglês:

Abstract The goal of this research was to evaluate the flooding tolerance of sugarcane genotypes under recurring floods of both plant and ratoon canes. Control and recurring flood conditions were compared using 10 sugarcane genotypes. As a result of the flooding, cane height increased and tillering decreased. Flooding reduced cane yield and commercial cane sugar (CCS) yield, as well as the percentage of polarization (POL), purity, and CCS in sugarcane juice. Sugarcane flood tolerance varied by genotype, with KPS01-4-29 and SP94-2-483 having the highest flooding tolerance index and KK07-037, K95-84, and KK07-599 having the highest yield under flooded conditions. Furthermore, under flooded conditions, a relationship between yield traits, cane height, and cane number was observed in sugarcane (r = 0.45* to 0.92**). As a result of our research, flood-tolerant sugarcane genotypes could be selected. Sugarcane genotype selection for flooding tolerance could include cane height and cane number as indirect traits.

Resumo em Inglês:

Abstract The ornamental kale, scientifically known as Brassica oleracea var. acephala, stands out as an attractive plant admired for its vibrant leaves that grace the winter season. Notably, the hybrid KTOK-28-1 × KTOK-40-1 demonstrated the highest embryogenesis rate, yielding 56.12 embryos per Petri dish. This efficiency largely hinges on the characteristics of the donor plants used. Through flow cytometry analysis, approximately 61% of spontaneous doubled haploids (DH) were identified. These individuals exhibited normal flower development and successfully produced seeds when subjected to bud pollination. The compatibility index values exhibited variation among different DH lines, ranging from 1.0 to 13.12. This diversity is promising for the development of superior hybrids. Noteworthy among the DHs were KTDH-52, KTDH-56, and KTDH-57, exhibiting suitability for various horticultural traits. The emergence of these novel DH lines suggests their potential contribution to future breeding programs aimed at producing superior-quality hybrids.

Resumo em Inglês:

Abstract Indian mustard (Brassica juncea) is an important contributor towards edible oil supply in India. Traditional Indian mustard varieties contain high proportion of 18C polyunsaturated fatty acids (linoleic and linolenic acids) and large amounts of long-chain monounsaturated FAs, mainly erucic acid, in seeds. Oleate desaturase (FAD2) regulates the composition of 18C PUFAs in cellular membranes and TAG in seed oil. The present study was conducted to gain insight into the allelic diversity of the FAD2 gene in Indian mustard. Analyses of cloned FAD2 genes of three Indian mustard varieties revealed a novel FAD2 gene that has a longer ORF (1167 bp) owing to insertions and several SNPs across its length that distinguish it from the more prevalent native FAD2 gene. Overall, the Indian mustard varieties possess three FAD2 alleles, but there is limited nucleotide diversity among members of each FAD2 type across varieties, suggesting narrow genetic diversity among the varieties examined.

Resumo em Inglês:

Abstract The aim was to estimate the minimum number of plants required per plot to assess the anthracnose severity by artificial inoculation of V2 stage plants. Seventy-eight carioca common bean cultivars were inoculated in 13 experiments to assess its reaction to races 65, 73, 81, and 89 of Colletotrichum lindemuthianum. Sample sizes ranged from one to nine plants were adopted to setting the number of plants per plot. A total of 1000 samplings were performed for each sample size. The following parameters were estimated in each sampling: accuracy, coefficient of variation and Pearson's correlation. The mean values ​​of each parameter in the 1000 samplings for each sample size were subjected to quadratic regression with a plateau as a function of sample size for each experiment. Six plants per plot were needed to assess the severity of anthracnose by artificially inoculating the pathogen on common bean plants at the V2 stage.

Resumo em Inglês:

Abstract The aim of this study was to evaluate chemical characteristics and biological activity of progenies from the first cycle of recurrent selection of Varronia curassavica in order to identify promising progenies for the next stages of the breeding program. The seeds were collected from the parental accession VCUR-503 (chemotype E-caryophyllene/viridiflorol) and subsequently sown in seedling containers and transplanted to the field. The essential oil was extracted 300 days after transplanting, and the levels of E-caryophyllene and viridiflorol were analyzed, as well as their activity against the protozoan Ichthyophthirius multifiliis. Application of the recurrent selection method resulted in increased levels of both compounds. The levels of E-caryophyllene (0.00-23.61%) and viridiflorol (0.00-64.74%) exhibited significant variation within the population under study. The essential oil rich in viridiflorol from progenies led to high mortality (72%) of the protozoan. Promising progenies for the second cycle of recurrent selection were identified based on the variables analyzed.

Resumo em Inglês:

Abstract We aimed to estimate genetic parameters and select sorghum lines for forage purposes based on agronomic and chemical traits. A total of 100 inbred lines, comprising the biomass/bmr, biomass, dual purpose (sweet/forage), and forage types, were evaluated in the 2020/2021 and 2021/2022 crop years. We analyzed the data using a linear mixed model approach. Genetic variance, line mean-based heritability, selection accuracy, genetic correlation between traits and crops and the coefficient of experimental variation were estimated. The breeding values of the lines were predicted, and the factor analysis and genotype-ideotype distance index based on BLUP (FAI-BLUP) were applied for multi-trait selection. Biomass production and cell wall composition traits were measured. There was genetic variation among the lines, with moderate to high heritability. The lines selected by the FAI-BLUP index resulted in significant genetic gains expected with selection for all traits.

Resumo em Inglês:

Abstract The climatic and edaphic conditions of the semi-arid Brazilian Northeast region limit the production of several annual crops, including cotton. The aim of this study was to estimate the genetic parameters and select water stress tolerant cotton lines based on yield and fiber quality traits. Twenty cotton lines were evaluated in Alagoinha-PB over two years under rainfed conditions. Individual and joint analysis of variance was performed on the data. Genetic parameters were determined, and lines were selected using the selection index. The lines CNPA SA 2019-115, CNPA SA 2019-185, CNPA SA 2019-109, and CNPA SA 2019-165 were selected for further tests in the region for recommendation of new cultivars. These lines can form new blocks of crosses, together with the BRS 286 check cultivar, as they have the best mean yield and fiber quality values, with the expectation of significant genetic gains.

Resumo em Inglês:

Abstract NCED1 (9-cis-epoxy carotenoid dioxygenase) plays important roles in controlling ABA levels and drought stress tolerance. The relationships between sequence polymorphisms of the TaNCED1 gene and drought resistance in wheat were analysed. Four allelic variations of the TaNCED1-5B generated to drought resistance were identified. Four groups of KASP (kompetitive allele-specific PCR) markers were developed based on the four alleles and were verified in a natural population of 311 wheat cultivars. The distribution of the four alleles of TaNCED1-5B in the natural population was clarified. Among the allelic variations, 84.62% of the wheat varieties with TT/-/C/-,TT/C/C/-,TT/-/C/G or TT/C/C/G haplotypes were dryland cultivars. The common feature of the above four haplotypes is that they all contain the TT (98) and C (343) alleles at the TaNCED1-5B-TT/CG (98) and TaNCED1-5B-C/T (343) loci, which indicated that these two locis had highly positive correlation with drought resistance in wheat.

Resumo em Inglês:

Abstract Lipids are compounds that play an important role in coffee bean development, contributing to beverage quality. Genome-wide association studies (GWAS) were conducted to pinpoint quantitative trait nucleotides (QTNs) linked to lipid metabolism in Coffea arabica. Genotyping by sequencing (GBS) and phenotyping data from 104 wild C. arabica accessions, Mundo Novo cultivar, and C. arabica var. Typica were utilized. GBS data were aligned to C. arabica Et039 reference genome, and both single-locus and multi-locus GWAS methods were employed. Methods were adjusted for kinship matrix, population structure, and principal component analysis. Of the 19 QTNs identified, 5 showed consistency across different population structure adjustments. The multi-locus methods mrMLM and FarmCPU proved more effective in identifying QTNs associated with lipid content. Four QTNs were situated near seven genes potentially involved in lipid metabolism. Higher frequencies of identified QTNs in accessions with elevated lipid content suggest their utility as markers for coffee plant breeding.

Resumo em Inglês:

Abstract BRS Boitatá and BRS Ocauçu cassava cultivars for the industry have high root and starch yields and high starch contents in first-cycle and second-cycle harvests, medium tolerance to the main diseases, adequate architecture for mechanized planting and stability in starch contents.

Resumo em Inglês:

Abstract Genetically modified (GM) crops have been on the market for almost 27 years and since the beginning have been protected by intellectual property (IP) rights that restrict their use and commercialization by third parties. In addition, their development is typically associated with elevated costs, making their production by public research institutions extremely difficult, especially in developing countries. Nevertheless, many patents for the first generation of GM crops have already expired, and others will do so soon, opening the path to generic GM crops. Using technologies in the public domain makes it possible to deliver GM seeds adapted to the local environment at affordable prices. This paper describes the development of the first Latin American off-patent GM corn and discusses the relevant IP and regulatory issues that allowed its commercial release in Colombia. The approach exposed here can be utilized for other crops or characteristics of agronomic interest.