Resumo em Inglês:

Abstract The purpose this study was to verify the breeding potential of Flintisa Composite for low (LT) and high (HT) technology of cultivation, and the best selection strategy to be adopted. For this reason half-sib progenies were evaluated in the two technological levels. In HT, it was used basic fertilization, two top dressing and supplementary irrigation. In LT, these practices were suppressed, and less fertile soil was used. Except for grain yield (GY), heritability was high at plant level and at progenies mean level. With mass selection, estimated gains ranged from 3.3% (GY in LT) to 41.8% (tassel branches number in LT). For half-sib selection, estimated gains ranged from 4.7% (plant height in HT) to 23.6% (erect plants in HT). For ear height, stratified mass selection in just one environment should be valid for both. Half-sib selection, with S1 recombination should be adopted in specific selection programs for LT and HT.

Resumo em Inglês:

Abstract Avocado is an economically important crop and widely cultivated in the tropical and subtropical regions of China, whereas little is known about its genetic diversification. Twenty-six EST-SSR markers were developed based on avocado EST sequences. Molecular characterization was applied to assess the genetic relationships among different accessions. In total, nine gSSRs and nine EST-SSRs were selected to illuminate the genetic relationships within the 92 samples. Diversity parameters associated to the selected markers indicated the relatively low genetic diversity and a certain degree of inbreeding in the 92 avocado accessions. Clustering method and principal coordinate analysis clearly distinguished the accessions in accordance to the botanical races and geographic regions by molecular characterization. Moreover, the botanical race or hybrids of some unknown race accessions from different geographic origins could be determined based on known genotypes in the same cluster..

Resumo em Inglês:

Abstract Physiological disturbances are one of the major bottlenecks to the expansion of papaya crops due to the negative influence on fruit quality. Studies on genotypes of light-green color have become essential to the development of strategies of tolerance to the physiological disorder skin freckle. Understanding the inheritance of qualitative traits is crucial to selection and prediction of the behavior of segregating generations. Thus, this study aimed to determine the inheritance of the qualitative trait leaf color in segregating generations of crosses between the dark-green cultivar BSA and the light-green cultivar GPC. Inheritance was determined based on the Mendelian genetics laws, by evaluating the phenotypic proportions in the analysis of generations P1 (BSA), P2 (GPC), F1, F2, BC1, BC2, BC2r, and F2:3. The inheritance of light-green leaves from the crossing between BSA and GPG is due to double recessive epistasis.

Resumo em Inglês:

Abstract MON810 is a genetically-modified (GM) maize (Zea mays) event commonly employed in insect-resistant GM maize hybrids. GM events obtained by biolistic transformation methods, such as MON810, are generated by insertion of a recombinant gene expression cassette in a random locus of the plant genome, and this process may cause emergent properties besides the intended modification. Here, we compared morphophysiological parameters of MON810 GM maize hybrid AG-5011YG and its non-GM near-isogenic hybrid (NIH) AG-5011, using in vitro cultures as an interactive model. NIH callogenesis frequency, callus friability, and de novo morphogenesis were compared using two explant types and different 2,4-dichlorophenoxyacetic acid (2,4-D) levels. 2,4-D modulated the morphophysiological responses of both NIHs, but when using root segments as explants, the GM showed significantly different trends for callus induction and friability, with lower responses at higher 2,4-D concentrations, indicating an emergent property related to altered cell response to 2,4-D.

Resumo em Inglês:

Abstract Plantations made up of clones carry genetic uniformity that can compromise production. The use of multiclonal plantations is a possible solution. The objective of this study was to identify effects of competition on silvicultural performance of Eucalyptus spp. commercial clones. The experiment was carried out in a randomized block design with 12 eucalyptus clones, three replicates, and five plants per plot. Clones were evaluated for two competition types, intra- and intergenotypic, at 3 and 5 years of age. Competition parameters were estimated based on the analyses performed. Differences were found between the types of competition at both ages for mean annual increment and wood volume. Clones 8 and 9 stood out from the others in both intra- and intergenotypic competition. At 5 years of age, intergenotypic competition produced productivity gains of 13% in clones 8 and 9 and 4% overall considering wood volume and mean annual increment.

Resumo em Inglês:

Abstract This study aimed to select cotton genotypes adapted to semi-arid conditions grown with supplementary irrigation. Two experiments were carried out between March and July 2016 in Serra Talhada- Pernambuco and Apodi-Rio Grande do Norte, Brazil. Eighteen elite genotypes bred by Embrapa Cotton and two controls (BRS 286 and BRS 336) were evaluated under drip and sprinkler irrigation. The experiment consisted of a randomized complete block design with four replications. Agronomic and fiber quality traits were evaluated. The data were subjected to individual and combined analysis of variance, and genotypes were selected by the Mulamba and Mock selection index (1978). The genetic parameters evidenced the possibility of significant gains in the selection process of cotton plants. The four genotypes (CNPA 2006-3052, CNPA 2004-266, CNPA 2006-1073, and CNPA 2005-125) with highest total genetic gains for the studied traits were considered the most promising.

Resumo em Inglês:

Abstract Plant breeding of ornamental peppers (Capsicum spp.) can be supported by biotechnological tools. The objective of this study was to evaluate the efficiency of an in vitro culture of immature zygotic embryos (IZE) to reduce the breeding cycle of ornamental pepper (C. annuum) in comparison to the conventional system. Three ornamental pepper genotypes were used: UFPB 001, UFPB 004, and UFPB 099. Embryos at 30 days after selfing were inoculated in MS ½-strength culture medium, and at the same time, seeds were placed to germinate in a commercial substrate. Approximately 215 days are required from selfing until fruit ripening in the conventional system, whereas the IZE system requires an average of 153 days, a decrease of approximately 30% per selection cycle, corresponding to 496 days considering 8 selfing cycles. A decrease in time, labor, and inputs makes the IZE system a suitable tool for shortening the breeding program of ornamentals peppers.

Resumo em Inglês:

Abstract Plant height (PH) is controlled by quantitative trait loci (QTLs) in rice. In the present study, a recombinant inbred line population developed by crossing two rice cultivars, Lemont and Yangdao4, was grown in eight environments for QTL analysis. Multiple interval mapping detected 53 PH-QTLs, 39 of which clustered at 12 chromosome regions/putative loci. An examination of the 12 putative loci identified 24 alleles that are simultaneously involved in controlling PH. Linear regression analyses suggested that these 24 alleles function additively across the 12 loci to control PH, and plants carrying more PH-increasing alleles at the 12 loci were taller than those carrying more PH-decreasing alleles. Multiple comparison tests indicated that the effect of a single allele at the 12 loci was small and that multiple alleles must be pyramided to attain a statistically significant effect. The closest markers to the 12 loci can be used directly in marker-assisted breeding to manipulate PH.

Resumo em Inglês:

Abstract A T1 (sugarcane population originating from true seeds) and T2 (first sugarcane clonal stage) population were used to estimate genetic parameters and compare selection strategies for Diatraea saccharalis (Lepidoptera: Crambidae) resistance in sugarcane. In the T1 stage, heritability at the family mean level (h²=0.77) was higher than individual genotype heritability (h²=0.16), and the additive genetic effect was more important for sugarcane borer resistance than non-additive effects. In addition, there was high genotypic variance among and within full-sib families. In the T2 population, genotypic variance was high, and heritability at the clone mean level was moderate (h²=0.61). We can conclude that family experiments enable selection of more promising families and parents for borer resistance. However, due to high genotypic variance within families, family selection at the T1 stage must be followed by clone selection at the T2 stage.

Resumo em Inglês:

Abstract Improving rainfed wheat cultivation in central Brazil, where the Cerrado biome (Brazilian savanna) is predominant, remains a bottleneck for future increases in domestic wheat production. In the Cerrado, the limited water availability during the wheat-growing season is an obstacle to increase wheat yield. To address this issue, the physiological and molecular drought response of wheat and the environmental conditions of this region must be better understood. In this review, we characterized the impact of drought on rainfed wheat production in the Cerrado. Based on the peculiarities of this environment, we suggest that certain traits should be prioritized in selection. These traits and their molecular basis are important to raise wheat yields in the Cerrado and also to improve food security in Brazil, one of the top wheat-importing countries in the world.

Resumo em Inglês:

Abstract The papaya cultivar UC14, recommended for the Southeast and Northeast regions of Brazil, was developed by UENF/CALIMAN breeding program. ‘UC14’ produces smaller fruit than those of Formosa hybrid, with a mean weight of 0.8 kg and a mean fruit yield of 199.45 t ha-1.

Resumo em Inglês:

Abstract RB005014 was developed for the Brazilian central-south region, for harvesting between July and September and planting on soils that have moderate or higher fertility levels. It has high tillering, high sucrose yield, excellent ratooning ability after mechanical harvesting, resistance to the main diseases and carries the Bru1 gene of brown rust resistance.

Resumo em Inglês:

Abstract The purpose of this study was to describe the main traits of the super-sweet maize cultivars ‘UENF SD 08’ and ‘UENF SD 09’, which produced higher yields than the control cultivar in the VCU (Value for Cultivation and Use) test series and proved to be competitive under the agro-climatic conditions of Northern and Northwestern Rio de Janeiro State.

Resumo em Inglês:

Abstract BRS FP403 is a common bean cultivar from the black bean market class with high grain yield and yield potential, high commercial and cooking quality, and moderate resistance to fusarium wilt (Fusarium oxysporum f. sp. phaseoli) and root rot diseases (Fusarium solani f. sp. phaseoli and Rhizoctonia solani).