Resumo em Inglês:
Abstract The aim of this study was to estimate genetic parameters and to select promising common cashew tree genotypes in commercial growing areas in four environments in Piauí (Piracuruca - P, Barro Duro - B, Teresina - T, and Ipiranga do Piauí - I) using the mixed model approach. Genetic variances were significant for most of agromorphological and physicochemical traits of the cashew nut and accessory fruit. The physicochemical traits exhibited more genetic variability and less environmental influence. The genetic correlations among traits were significant, positive, and of medium to high magnitude, except for titratable acidity and total soluble solids. The prominent genotypes for the agromorphological traits were 115(I), 110(I), 92(T), 38(P), 108(I), and 103(I); for titratable acidity, 31(P), 118(I), and 74(B); for total soluble solids, 124(I) and 112(I); and for total soluble solids/titratable acidity, 109(I) and 47(P). The selected genotype 115(I) exhibited superior performance for most of the traits.Resumo em Inglês:
Abstract This study was conducted to identify the allelic interactions and genetic effects involved in genetic control of quantitative traits in Capsicum annuum. Six generations (P1, P2, F1, F2, BC1 and BC2) were used to study the variances, means and allelic interactions of 16 quantitative traits evaluated. The additive part of the phenotypic variance found for plant height, number of peppers per plant, days to flowering and days to fruiting lead to the conclusion that phenotypic selection in the F2 generation are likely effective in obtaining genetic gains. According to the reduced model, the traits of canopy width, fruit width and number of seeds per fruit were not influenced by epistatic effects, but only by additive and dominant effects, which allows selection of superior individuals in segregating generations or improvement of these traits by means of hybridization.Resumo em Inglês:
Abstract Citrus plants have a long juvenile period, which has hampered the breeding progress of these species. In this sense, research focused on reducing the juvenile phase is needed to accelerate the breeding process. In this study, the morphology of the hybrid {[(‘Rangpur’ lime) x YMCT (‘Yuma’ citrange) - 005] x (Microcitrus papuana) - 001} (H011), which has a short juvenile period, and the gene expression levels of the FLOWERING LOCUS T (FT) were evaluated. Morphological studies indicated early flowering and fruiting of the hybrid, characteristics that make it a promising candidate for citrus breeding. In addition, winter temperatures influenced the expression of the FT gene in stems and leaves.Resumo em Inglês:
Abstract In the northern Minas region, the dry-warm climate predisposes coffee plants to the occurrence of leaf miners, mites, cercosporiosis, and leaf scald. Aiming for the development of a cultivar adapted to these conditions, Coffea canephora Pierre ex A. Froehner clones were selected through genetic parameters under an irrigated system, without agrochemicals. Eighteen agronomic traits were evaluated. The survival rate, number of nodes per plagiotropic branch, leaf miner infestation and cercosporiosis incidence were chosen as characteristics for selection of ‘Vitória Incaper 8142’, once they have shown superiority of the genetic parameters. The survival rate variable was used to rank the EMCAPA 8141 Robustão Capixaba clones. Clones V2, V4, V6, V13, RC7, and RC9 were selected as more tolerant to pests and diseases and can provide genetic improvements in conilon breeding program for region. The genetic dissimilarity identified between clones allowed suitable clone combinations to be proposed for use in future crosses.Resumo em Inglês:
Abstract Although cultivars of autogamous plants are homogeneous genotypes, they may show natural variability due to mechanical mixing, natural hybridization, and mutation. The aim of the present study was to estimate genetic and phenotypic parameters and to identify and select superior genotypes that associate good performance in traits of interest from a heterogeneous population derived from the cultivar BRS Favorita RR. The evaluation experiments were carried out in two crop years and five cities of the state of Minas Gerais, Brazil, in a lattice design, using progenies and the control ‘BRS Favorita RR’. Plant height, first pod height, days to full maturity, lodging score, and grain yield were evaluated. For estimation of the variance components, analysis of deviance was performed by the restricted maximum likelihood (REML) method. The results show that there is difference among treatments and that it is possible to select progenies that outperform the control for all traits evaluated.Resumo em Inglês:
Abstract Genotypes of the chrysanthemum cultivars Harman and Indianapolis were transformed using Agrobacterium tumefaciens strain LBA4404, which carries the binary plasmid pBIN19::Rd29A::ScTPS1TPS2::nos and pBIN19::35S::ScTPS1TPS2::nos, respectively. ISSR markers were used to discriminate two cultivars from each other, and independent transgenic plants generated in each cultivar. Firstly, the nptII gene and Tnos sequence in the transformed genotypes was confirmed by PCR. For genotyping, 10 ISSR profile markers produced 131 DNA bands. The percentage of polymorphism ranged from 20 to 82.4 %. Primer UBC 872 provided the highest percentage of polymorphic bands (PBP), polymorphic information content (PIC), marker index (MI) and resolving power (Rp). A positive correlation was found between the Rp value of each primer and the number of identified genotypes (r=0.822***). The UPGMA analysis generated two groups with a similarity coefficient of 0.67. The genotype grouping was confirmed by PCoA. The ISSR technique was efficient to discriminate transgenic cultivars from non-transgenic plants.Resumo em Inglês:
Abstract Perennial grass hybrids of Urochloa are evaluated for at least two years during the screening stage trials (SS) and advanced trials (AD) in breeding programs, an expensive and time-consuming process. In this study, we aimed to evaluate the potential for early selection of cultivars in this breeding scheme. We used multiple measurements of agronomic and nutritive value traits of Urochloa humidicola and Urochloa decumbens in the SS, and Urochloa ssp. in the AD. Repeatability coefficient, genetic correlation, selection efficiency (SE), and Spearman correlations were estimated. The results indicated that reliable early selection could be applied, decreasing the evaluation period to one year and a half for SS, and to one year for AD. These results were confirmed by high genetic and rank correlations, and overall SE above 50%. This proposed change in the breeding scheme could save considerable time, labor, and resources and accelerate the release of improved cultivars.Resumo em Inglês:
Abstract The aim of this study was to analyze traits of leaf appearance and phenological development related to grain yield gain in winter barley cultivars released over the past 50 years. Field trials with 15 six-rowed winter barley cultivars were conducted during two growing seasons. The main leaf appearance and developmental traits were studied. The duration of the emergence-anthesis and emergence-physiological maturity phases decreased by 2.35 and 2.16 GDD yr-1, respectively. The duration of the stem elongation-anthesis phase was 10% longer in modern cultivars. The results showed no clear trend of improvement in final leaf number and phyllochron. The duration of the stem elongation-anthesis phase was positively related with grain number and yield. Constant improvements in grain number and grain weight by fine manipulation of the crop developmental phases could represent an essential strategy for further increases in barley grain yield potential.Resumo em Inglês:
Abstract Fifty wheat genotypes were evaluated at nine diverse locations in India to identify high-yielding and stable genotypes. The analysis of variance based on additive main effects and multiplicative interaction (AMMI) indicated significant genotype, environment and genotype - environment (GE) interactions, with a total variation of 5.99, 20.23 and 73.77%, respectively. A biplot-AMMI analysis and yield stability index incorporating the AMMI stability value and yield in a single non-parametric index were used to discriminate the genotypes with highest and stable yield; the genotypes G135, G125, G104, G112 and G144 were found to be promising. Two mega environments (ME) were identified based on GGE (genotype and GE interaction) biplot analysis and the genotypes G119 and G120 and G107, G148 and G146 performed best in the mega-environments ME I and ME II, respectively. Both approaches allowed the identification of stable genotypes (G112 and G135), which can be included in the national testing program, with a view to release a new variety.Resumo em Inglês:
Abstract The peach breeding program of the Brazilian Agricultural Research Corporation (Embrapa), addressing the adaptation to mild winter conditions, is one of the largest in the world and maintains a germplasm collection of nearly 900 accessions. The objective was to estimate the genetic progress in fruit weight (FW) and fruit development period (FDP) resulting from the above program, by analyzing data records of 16 years (2000 - 2015) of 65 genotypes. Based on samples of ≥ 10 fruits, the mean annual FW (in g) and FDP (in number of days) from full flowering to harvest were determined. In the 16 years, the gain in FDP consisted of respective reductions of about -12.8, -3.3, -2.8 days for canning peach, fresh peach and nectarine. However, the genetic progress in fruit weight was 5.3, 1.4 and -17.9 g fruit-1 for canning peach, fresh peach and nectarine, respectively.Resumo em Inglês:
Abstract Dipteryx alata Vogel (Leguminosae) is a native Neotropical tree with a wide distribution in the Brazilian Cerrado that is commonly known as the baru tree. The genetic diversity of 150 D. alata progeny from a germplasm collection was characterized using nine microsatellite markers. Genetic diversity analysis detected 50 alleles ranging from 2 to 14 alleles per locus. The genetic differentiation among populations (θ p = 0.097) suggests moderate genetic structuring and high genetic differentiation among progenies (θ s = 0.169). The intrapopulation index (f = 0.122) indicates the presence of low endogamy. The effective population size (Ne = 96) shows that the germplasm collection has sufficient representativeness for use as a base population for breeding programmes. These results are useful for the exploitation of the genetic resources of D. alata for future conservation efforts and breeding programmes.Resumo em Inglês:
Abstract We evaluated the genetic variability of a collection of Jatropha curcas germplasm, represented by 93 accessions, using microsatellite markers. Among the 60 markers tested, five of them detected polymorphisms, with a total of 11 alleles and mean of 2.2 alleles per loci. These five markers enabled the quantification of genetic variability through estimates of expected (He=0.42) and observed (Ho=0.64) heterozygosity, Shannon-Weaver index (H'=0.62), coefficient of inbreeding (ƒ=-0.44) and the formation of 11 clusters. Simultaneously, 14 accessions randomly sampled among the 93 and represented by seven plants each, were analyzed with these same five markers to quantify the within and between variability. Most of the genetic variation (92.58%) was contained within the accessions. These analyses revealed, for the first time, expressive genetic variability to be explored in this collection. The accessions UFVJC 05, 07, 12, 18, and 53 presented expressive variability among them with potential for the constitution of a base population for the breeding program.Resumo em Inglês:
Abstract The E’AppleBP is the largest Brazilian apple breeding program in activity in Brazil, with Brazilian and international contributions to breeding of apple cultivars, under public funding. The main objectives are development of new apple cultivars with good local climate adaptation, disease resistance, high yield, high fruit quality, good fruit storability and lower demand for orchard hand labor. Twenty-seven apple cultivars have been released, including 15 from local breeding crosses and four sport mutations. ‘Fuji Suprema’, ‘Monalisa’, ‘Venice’, ‘Daiane’, ‘Luiza’, and ‘Kinkas’ are most promising for commercial use. The other eight cultivars were released for use as pollinizers.Resumo em Inglês:
Abstract The cultivar IAC Catuaí SH3 was developed by the pedigree method, from the recombination of the coffee tree H 2077-2-5-46, of the Catuaí Vermelho germplasm, with accession IAC 1110-8, from the exotic cultivar BA10. Cultivar IAC Catuaí SH3 is high-yielding, resistant to coffee leaf rust and tolerant to drought.Resumo em Inglês:
Abstract Soybean cultivars with "plasticity" traits, such as good branching ability, ensure compensation of gaps in planting. The cultivar INT7100 IPRO provides excellent branching ability and plant architecture, facilitating control of pests and diseases, and it contains the biotechnology INTACTA RR2 PRO®. It is resistant to stem canker, brown stem rot, and bacterial blight.Resumo em Inglês:
Abstract The hybrid of Cattleya forbesii x Cattleya loddigesii has a short stature and early flowering, a light lilac tending to white color and a labellum with a velvety purple lobe and corrugated edges. The flower lifetime lasts approximately 20 days.Resumo em Inglês:
Abstract BRS Catiana is an irrigated rice cultivar with a medium cycle and excellent grain quality, suited for cultivation in 17 Brazilian states. It has a high yield potential (15,535 kg ha-1) and a mean yield of 7,253 kg ha-1, wide adaptation and late senescence (stay green trait).Resumo em Inglês:
Abstract BRS 425 is a high-oleic runner peanut cultivar related to wild ancestral parents, partially resistant to early and late leaf spot and spotted wilt. It is large-seeded and contains 46% oil. BRS 425 is adapted to the main peanut-producing regions of Brazil.Resumo em Inglês:
Abstract IAC 1850 is a common bean cultivar with a carioca (beige-colored with brown stripes) seed coat, average cycle of 88 days, semi-upright plant architecture, tolerance to seed coat darkening, 1000 seed weight of 280 grams, resistance to the main diseases in common bean, and a high average yield (2,857 kg ha-1) obtained in 36 experiments conducted in different regions in Brazil.Resumo em Inglês:
Abstract BRS Anauê and BRS Boyrá are two ornamental pineapple cultivars bred for landscaping and cut flower and mini fruit production. They are characterized by intense colors, absence of spines, a long peduncle and high durability. In Brazil, they are the first pineapple cultivars officially released for commercial ornamental purposes.