Resumo em Inglês:

Abstract Carioca grains are the most cultivated commercial group of common bean and Fusarium oxysporum f. sp. phaseoli (Fop) is an important disease under field conditions. Genetic resistance is the most effective control strategy. Thus, our objective was to study the inheritance of Fop resistance in the carioca grain type common bean. Lines CNFC 11965 (S) and CVIII 8511 (R) were crossed to obtain F1 and F2 generations and backcrosses, inoculated with the isolate FOP UFV 01, and severity grades used to estimate genetic parameters. Segregation of resistant and susceptible plants in the F2 generations and backcrosses resulted in dominant monogenic inheritance of Fop resistance. The high values of heritability emphasized the probability of success in the selection processes because environmental factors were not significant. The carioca grain line CVIII 8511 is promising, and its Fop resistance gene can be transferred to commercial cultivars of this group using the backcross method.

Resumo em Inglês:

Abstract Palm trees are the third most important botanical family for humans because of their potential use in oils, drugs, cosmetics, food, and feed. Despite their importance, little information on their genetics and molecular variations exists, and a better understanding could contribute to breeding programs. This study aimed to determine the amount, distribution, and organization of plastid simple sequence repeats (cpSSRs) and their potential use in breeding in 52 species belonging to the order Arecales. Plastid genomes were analyzed to identify cpSSRs according to their nature, position, and presence in genic or intergenic regions. Primer pairs were validated in silico for amplification and polymorphisms in these SSRs and their dissimilarities were evaluated. The results showed a high frequency of mononucleotide repeats in the intergenic regions. Approximately 76 primer pairs were generated and are suggested for further studies. The dissimilarity analysis of cpSSRs showed that mono- and trinucleotides were highly abundant in plastid SSRs.

Resumo em Inglês:

Abstract Disease resistance gene pyramiding is a widely used strategy to enhance resistance durability. Marker-assisted selection (MAS) was applied to pyramide the alleles Run1 and Ren3, which confer resistance against grape powdery mildew (Erysiphe necator). Two F1 full-sibs carrying Run1 and Ren3 in heterozygosity were selfed to develop the breeding populations used in the analysis. From the 637 genotyped plants, 313 (50.6%) had the Run1 and Ren3 pyramided. Seven (1.1%) of them exhibited the two resistance alleles in homozygosity. Plants without any resistance alleles had the highest disease severity ( = 7.3), while the ones with the Run1 allele both in homozygosity and heterozygosity were highly resistant ( = 1.5). Similar level of resistance was observed in the plants containing Run1 and Ren3 pyramided ( = 1.3). Plants containing Run1 and Ren3 pyramided in homozygosity are important genetic resources for grape breeding programs in Brazil.

Resumo em Inglês:

Abstract This study aimed to compare recombinant inbred lines (RIL) obtained via the bulk method with doubled haploid lines (DHL). For comparison, 190 DHL and 194 RIL were evaluated simultaneously at two different locations. Phenotypic and genetic parameters were estimated for the traits green leaf yield (GLY) and alkaloid content (ALK). The results of the RIL and DHL evaluations were similar for ALK. Conversely, estimates of genetic variation and heritability in the DHL were higher than those in the RIL for GLY. However, the mean estimate of the RIL was 13.3% higher than that of the DHL and thus, the annual gain with selection was higher for the RIL. The use of DHL in a recurrent selection program will be efficient in comparison to RIL if a large number of lines are obtained, which must undergo a preliminary selection before the most intensive evaluation to identify the lines to be recombined.

Resumo em Inglês:

Abstract Few commercial genotypes of tomato are resistant to Fusarium wilt (Fusarium oxysporum f. sp. lycopersici [FOL]), especially to race 3. We developed five intraspecific hybrids of Solanum lycopersicum (FOX1 to FOX5) and assessed them for agronomic traits and resistance to FOL races 1, 2, 3, and a mixture of these races. FOX1 and FOX4 were resistant to all races and the race mixture but did not have the desired agronomic traits. Next, FOX1 and FOX4 were assessed as rootstocks of the cherry tomato Sweet Heaven. The grafting of Sweet Heaven on FOX4 did not reduce growth, gas exchange, yield, or fruit quality. When FOX1 was used as a rootstock, the fruits exhibited a reduction in firmness, fruit pulp pH, and total soluble solids by 14.3%, 1.2%, and 6.75%, respectively. Thus, the hybrid FOX4 can be used as a rootstock for Sweet Heaven to manage Fusarium wilt.

Resumo em Inglês:

Abstract APA is a multigene locus that comprises the protein genes of arcelin (Arc), phytohemagglutinin (PHA) or lectin, and an α-amylase inhibitor (α-AI). These genes play essential roles in the defense responses of legume seeds to protect against seed weevils in common bean (P. vulgaris). During the evolution of this complex locus, PHA proteins appeared first, followed by α-AI and Arc proteins. This study compared and analyzed the sequences of three bacterial artificial chromosome (BAC) clones containing APA fragments of the genotypes G02771, BAT93 and DGD1962. These three genotypes are recognized as representative of the crucial steps of APA evolution in common bean. Our findings demonstrated that rearrangements during evolution can be used to characterize the APA locus, but concurrent adjacent gene regions on either side of the APA locus are highly conserved. Part of the instability of the APA locus may be due to the insertion of retroelements and gene conversion.

Resumo em Inglês:

Abstract The Thailand governmental institutes play important roles in genetic improvement of sweet corn in Thailand. We assessed the genetic diversity of 268 sweet corn inbreds from three major institutes (NCSRC-KU, CNFCRC, and KKU) and three commercial hybrids using 20 SSR markers. The markers detected 224 alleles in total, with an average of 11.2 alleles per locus. Overall gene diversity was relatively high, being 0.7. Allelic richness, gene diversity, and heterozygosity in the inbreds among the three institutes were comparable. However, the inbreds from KKU possessed the greatest number of unique alleles and rare alleles, albeit they showed the highest percentage of genetic impurity. Neighbor-joining, principal coordinate, and STRUCTURE analyses showed that the inbreds were genetically different. Our findings provide insight into the breeding gene pool and population structures of the sweet corn germplasm of the public sector in Thailand, enhancing efficiency of sweet corn germplasm utilization for developing new varieties.

Resumo em Inglês:

Abstract Acacia mearnsii De Wild. is one of the most widely cultivated forest species in Brazil. Despite its importance, studies on breeding strategies for this species are scarce. Therefore, the aim of this study was to evaluate the progeny and develop early selection strategies for A. mearnsii. Individuals of half-sib progenies were classified according to their genotypic value and selected based on their relative performance. The additive effect was only significant for plant height. The best progenies and plants should be selected based on plant height after approximately 60 days of being in nursery and 2 years of field cultivation. This strategy eliminates the worse progenies, discards inferior genotypes in the nursery, eliminates unselected genotypes based on plant height before flowering, and intercrosses only the best plants in field cultivation. This resulted in an annual genetic gain of 3% for plant height and 2% for diameter at breast height.

Resumo em Inglês:

Abstract Perennial plant breeding is an expensive and time-consuming process, mainly due to the extended growth time for juveniles. In these cases, the use of molecular marker-assisted selection (MMAS) allows for the selection of a characteristic of interest at the seed or seedling stages. The objective of this work was to characterize the segregation of the INO locus and to use MMAS for the early selection of seedless genotypes of atemoya 'Gefner' [(G; Annona cherimola Mill. × Annona squamosa L.) × Brazilian seedless (Bs; Annona squamosa)]. After primer validation and MMAS, 24 plants of the F2 population were selected and designated as candidate genotypes for the absence of seeds, as INO alleles were absent in them. For further studies on breeding programs for this species, 53 heterozygous seedlings were considered as genetic resources during selection.

Resumo em Inglês:

Abstract BRS 429 is a sweet cassava cultivar with yellow pulp and technological qualities (high root yield, early maturity, and favorable plant architecture) and sensory qualities (short cooking time, little fiber, and soft texture) that make it an excellent option for cultivation in the Distrito Federal, Paraná, and São Paulo, Brazil.

Resumo em Inglês:

Abstract BRS TR271 is a new wheat cultivar released by Embrapa for Brazilian wheat-growing regions 1 and 2 of Rio Grande do Sul, Santa Catarina, and Paraná. It has high grain yield potential and a super-early cycle. It is widely adapted and is classified as bread wheat.

Resumo em Inglês:

Abstract UFSMFW 2202 is an early black oat cultivar with high dry matter and grain yield potential. When used in rotation systems, the early cycle has the immediate advantage of allowing anticipated sowing of subsequent crop. Initially, the cultivar is recommended for the North and Northwest of Rio Grande do Sul.

Resumo em Inglês:

Abstract KU Gold’ is a papaya cultivar with attractive yellow fruit and pale-yellow pulp during its immature stage. It can produce year-round sweet fruit containing a high amount of ascorbic acid during its ripe stage. It also has great potential as an ornamental plant due to its pale-yellow petioles and flowers.

Resumo em Inglês:

Abstract The black oat cultivar UFSMFW 2101, recommended for Northwest of the state of Rio Grande do Sul, is very early and can produce high dry matter and grain yields. In rotation systems, an immediate advantage is the very early cycle, with the possibility of anticipated sowing of the subsequent crop.

Resumo em Inglês:

Abstract Napier grass is a perennial tropical forage that is used in beef and dairy production systems. Despite its significance in animal nutrition, molecular information available, such as microsatellite or simple sequence repeat (SSR) or single nucleotide polymorphism (SNP) markers, is limited. Using an assembled transcriptome, 50 novel SSR markers were developed, of which 21 were found to be polymorphic. These polymorphic markers were tested for DNA fingerprinting of Embrapa cultivars, five of which revealed distinct allele patterns for cultivar identification. SSR markers 05, 17, and 44 identified a unique pattern in the BRS Kurumi cultivar. The BRS Capiaçu cultivar was identified using SSR markers 17, 43, and 44. The Pioneiro cultivar exhibited a rare fragment amplification pattern using SSR marker 46, while SSR marker 44 revealed a distinct allele in the BRS Canará cultivar. SSR marker panels could be utilized as DNA fingerprinting tools to assist in cultivar identification.