Resumo em Inglês:

Abstract The sex phenotype in cucumbers, determined by the F locus, is crucial for crop productivity. Identifying markers for this trait aids in selecting gynoecious varieties for higher yields, but existing molecular markers show low correlation with the gynoecious trait. This challenge can be addressed by indirectly selecting target lines and eliminating monoecious genotypes through accurate screening. This study seeks to develop a molecular marker closely linked to the F locus to differentiate monoecious cucumber phenotypes. Genetic analysis of a 1,000 kb region around the F locus in both gynoecious and monoecious lines revealed two polymorphisms: a 34-base pair deletion (34Del) and a 16-base pair insertion (16In). Only the 34Del polymorphism consistently co-segregated with the monoecious phenotype, effectively distinguishing homozygous from heterozygous monoecious lines. Therefore, the 34Del polymorphism can serve as a reliable marker for use in cucumber breeding programs to improve yield.

Resumo em Inglês:

Abstract The expansion of cowpea (Vigna unguiculata (L.) Walp.) crop has created new demands for its breeding programs. Knowledge of its genetic base is fundamental for choosing progenitors when conducting crosses. This study aimed to estimate the genetic base of Brazilian cowpea cultivars released between 1960 and 2022, in addition to identifying the origin of their cytoplasmic genes. Seventy-three cultivars were released in this period; however, only 41 had information about their original crosses. The ancestors CNC0434, Pitiúba and Seridó were used more frequently in crosses. They have also contributed with the highest frequency to the cultivars’ cytoplasmic genes. Therefore, although we found that between 2005 and 2022 there was a 30.95% increase in the contribution of different genotypes, we conclude that the genetic base of cowpea is narrow, and it is necessary to avoid crosses involving CNC0434, Pitiúba and Seridó in future breeding programs of this legume in Brazil.

Resumo em Inglês:

Abstract Distinguishing Megathyrsus maximus genotypes in breeding programs based on morphological traits alone can be challenging. Thus, this study proposes the utilization of molecular traits to identify genetic differences and understand the characteristics of these genotypes. Twenty-four genotypes were sequenced, resulting in 341 bases within the trnL-trnF spacer and 459 bases from ITS2 sequences. These sequences were head-to-tail concatenated and analyzed for phylogenetic diversity. Substitution saturation analysis confirmed the sequences' suitability for phylogenetic reconstruction, as ISS value (0.0279) was significantly lower than its critical value (ISS.c = 0.7523). Both Maximum Parsimony and Bayesian Inference analyses yielded consistent results with most nodes showing support above 99%. PCoA analysis demonstrated a clustering pattern consistent with the phylogenetic tree, identifying two distinct groups with clear separation. Approximately 82% of the total variance was explained by the PCoA. The obtained genetic information serves as a valuable resource for developing M. maximus markers.

Resumo em Inglês:

Abstract Coffee leaf rust, caused by Hemileia vastatrix, is the most important disease affecting Coffea arabica. The use of molecular markers through marker-assisted selection (MAS) is an effective approach to develop cultivars with multiple and durable resistance, which is economically and environmentally beneficial for this disease control. In this work, a new molecular marker based on allele-specific polymerase chain reaction (AS-PCR) associated with the quantitative trait locus (QTL) of the linkage group 5 (LG5), which confers resistance to races I, II and pathotype 001 of H. vastatrix, was developed. The CaRHv10-AS marker was validated in a segregating genetic mapping population of 247 F2 genotypes and demonstrated selection efficiency greater than 97% for genotypes with resistance to three races. Thus, this work provides a fast, robust, and affordable molecular marker for use in MAS, facilitating the development of coffee plants with multiple resistance and ensuring sustainable coffee production.

Resumo em Inglês:

Abstract This study estimated genetic and phenotypic parameters, heritabilities, correlations, selection accuracy, and expected gain from selection for dry matter yield and nutritional traits in 178 half-sib ruzigrass families. Eight traits were evaluated, with nutritional quality measured via NIRS. Data analysis using mixed models and clustering revealed significant differences between progenies. Narrow-sense heritability ranged from 0.26 to 0.42, and selection accuracy ranged from 0.51 to 0.65. Genetic variation was lower for nutritional quality traits compared to dry matter yield. Dry matter yield had positive genetic correlations with neutral and acid detergent fiber and cellulose, but negative correlations with crude protein and hemicellulose. Clustering identified two groups of families: one correlated with in vitro dry matter digestibility and crude protein, and the other with remaining traits. Selecting for dry matter yield may reduce crude protein content but not affect digestibility; selecting for low fiber or high crude protein may improve forage quality.

Resumo em Inglês:

Abstract Common bean breeding obtained cultivars with high yield and resistance to diseases. We evaluated anthracnose resistance of genotypes from breeding programs where selection was made mainly to increase grain yield. A germplasm collection of 845 lines were assessed with four of the most frequent Colletotrichum lindemuthianum races found in Brazil (65, 73, 81 and 89). In addition to high reaction variability, we identified 633 lines resistant to at least one race. Most resistant lines have a Carioca grain type. The virulence indexes ranged from 51.7% to 63.2% (races 81 and 73) and resistance indexes ranged from 0% (susceptible) to 100% (resistant). This study presents complete characterization about resistance to anthracnose of a wide collection, provides information about cultivars that can be directly introduced in current breeding programs and shows that breeding focused on increasing grain yield has also been successful in selecting resistant genotypes to anthracnose disease.

Resumo em Inglês:

Abstract Pandanus amaryllifolius, a tropical fragrant screw pine, is commonly used in cooking and traditional medicine. Although studies have analysed its metabolite, transcriptome, and proteome profiles, molecular markers for genetic improvement remain scarce. This study aimed to develop EST-SSR markers from the P. amaryllifolius transcriptome and utilise them to analyse their genetic diversity. We obtained 157,467 unigenes with an average length of 1,084 base pairs. From these, 66,820 EST-SSRs were identified, with dinucleotides being the most common (45.5%). Following functional domain marker (FDM) analysis, 7,208 markers were used for in silico PCR, which revealed 8,843 polymorphic bands (86.9%), with an average polymorphic information content (PIC) of 0.41, gene diversity of 0.54, and a Shannon index of 0.91. The dendrogram and PCA plot clearly separated samples from Malaysia and India. These findings provide a new alternative for EST-SSR marker validation and a foundation for genetic improvement and conservation strategies for P. amaryllifolius.

Resumo em Inglês:

Abstract Camellia tienii, an indigenous plant species in Vietnam, is renowned for its remarkable medicinal properties. However, the current methods for plant identification are not reliable due to shared characteristics with other species in Camellia genus. To address this, the present study aimed to sequence and characterize the complete chloroplast (cp) genome of C. tienii. The resulting cp genome is 162,167 bp in size and encompasses 154 genes, including 98 protein-coding genes, 8 rRNA genes, and 48 tRNA genes. Notably, this genome contains 55 simple sequence repeats, specifically type A and T motifs. It is worth mentioning that the ndhF gene was not detected in this genome, while the trnL gene was present. Phylogenetic analysis revealed that C. tienii shares a close relationship with C. tamdaoensis. These significant findings contribute with valuable insights that can aid in the accurate taxonomy, plant identification, and conservation efforts concerning this herb in Vietnam.

Resumo em Inglês:

Abstract The aim of this study was to identify, through different methodologies, soybean cultivars with adaptability and stability for grain yield in environments with different levels of light restriction. The grain yield of sixteen cultivars was evaluated in environments with 25% and 48% restriction of photosynthetically active radiation (PAR) in the agricultural years 2019/2020 and 2021/2022. Based on the results, an adaptability and stability analysis was performed using the Eberhart and Russell, ANN (Artificial Neural Network) and GGE (Genotype plus Genotype-Environment interaction) methods. Grain yield varied with the levels of PAR restriction and agricultural years, being higher in environments A3 (2021/2022 25% PAR) and A1 (2019/2020 25% PAR), respectively. Cultivars NS7780, 8579RSF, NS8338 and RK6718 showed higher yield. The adaptability of cultivars AS3680, M7110, and 74177RSF was low, while that of NS8338 and NS7780 was high. Cultivars NS8338, 74177RSF, RK7518, and M6210 showed high phenotypic stability to environments.

Resumo em Inglês:

Abstract Maize is recognized as an exceptional forage crop with superior forage quality among cereal forage crops. For forage breeders, the primary objective is to identify high-yielding and stable genotypes. The aim of this study was to select superior and stable fodder maize hybrids from 195 single-cross hybrids on the basis of 16 variables. The selection was carried out using the MGIDI index within each season, with a selection intensity of 5%. Genotypes G48, G47, and G79, which had the lowest MGIDI indices in the rainy 2022, winter 2022, and summer 2023 seasons, respectively, were identified as superior in the 16 variables studied. In addition, the MTSI index was used to evaluate genotype stability across multiple traits, identifying genotype G24 as having the lowest MTSI index. These robust statistical tools proved effective in identifying the most stable and high-performing genotypes among the 195 single-cross forage maize hybrids analyzed.

Resumo em Inglês:

Abstract Lemongrass, an industrially important aromatic grass known for its essential oil, exhibits phenotypic traits that are influenced by environmental factors. This study evaluated the stability and adaptability of 13 advanced lemongrass breeding clones over several years. Significant genotype and genotype × environment interaction (GEI) effects on herbage yield and essential oil yield highlighted the influence of genetic and environmental factors on these traits. The AMMI and GGE biplot analyses identified clone 5 as a high performing and stable genotype for herb yield. Meanwhile, clones 1 and 4 showed consistent performance across years and were desirable for essential oil yield due to their proximity to the abscissa of the biplot. These identified clones represent valuable genetic resources for future breeding programs aimed at developing superior lemongrass cultivars for commercial cultivation.

Resumo em Inglês:

Abstract: Cultivar Magnus grano is made up of five genotypes that were selected by coffee growers in the state of Espírito Santo, Brazil. The cultivar shows good adaptation to growing conditions, high yield potential, and the largest beans among the studied genotypes.

Resumo em Inglês:

Abstract IPR Alvorada is a Coffea arabica cultivar with C. canephora introgression, developed from a cross between IAPAR 59 and Mundo Novo IAC 376-4. This cultivar has a dwarf-medium size, high yield, good cup quality, strong vegetative vigor, a medium fruit ripening cycle, and slight resistance to coffee leaf rust.

Resumo em Inglês:

Abstract BRS 700FL B3RF is an extra-long staple (ELS) upland cotton cultivar. It features exceptional fiber quality, with fiber length exceeding 33.0 mm and fiber strength above 32.5 gf tex-1. This cultivar includes transgenic events Bollgard® III and Roundup Ready Flex™, providing enhanced resistance to lepidopteran pests and tolerance to glyphosate.

Resumo em Inglês:

Abstract RB036152 sugarcane cultivar is known for its high cane yield and elevated sucrose content. In the central-southern region, optimal harvest period extends from July to November. This cultivar is particularly well-suited for mechanized planting and harvesting, demonstrates excellent performance in challenging environments, and shows strong tolerance to major sugarcane diseases.

Resumo em Inglês:

Abstract IPR Pérola is a Coffea arabica cultivar developed from a cross between IAPAR 59 and Mundo Novo IAC 376-4. It features a dwarf-medium size, high yield, excellent cup quality, a medium-early ripening cycle, and large beans. Additionally, it boasts high resistance to coffee leaf rust.

Resumo em Inglês:

Abstract SCS127 CL is a Clearfield® rice cultivar that is resistant to herbicides from the imidazolinone group, such as Kifix®. This cultivar features a modern plant type, resistance to lodging, a late maturity cycle, moderate resistance to leaf and panicle blast, high yield potential, long grains, and good cooking quality.

Resumo em Inglês:

Abstract Gossypium arboreum varieties NDLA 3116-3 and NDLA 3104-4 have mean seed cotton yield potential of 1257 kg ha-1 in central zone and 928 kg ha -1 in southern zone, respectively and are released for commercial cultivation in the respective zones of India by Regional Agricultural Research Station, Nandyal, India.

Resumo em Inglês:

Abstract This study examines Cenchrus purpureus with the aim of identifying genotypes and select plants progenitors resistant to Mahanarva spectabilis (Distant, 1909) for future recurrent selection from the elephant grass germplasm bank. Six M. spectabilis eggs were inserted into each plant of 138 elephant grass genotypes. After 35-45 days the percentage of nymphal survival was assessed. Despite the large variation in insect survival there were no significant differences in the joint analyses of bioassays conducted from 2008 to 2024. None genotype yielded an insect survival rate of less than 30%, and fewer than 10% of the genotypes showed a survival rate of less than 50%. These genotypes should be intercrossed, forming a new population each year, with the aim of increasing the presence of favorable alleles for resistance to this insect pest, with the goal of producing genotypes that achieve future M. spectabilis nymph mortality greater than 70%.