Sugarcane is the main sugar producing a crop in Côte d’Ivoire. However, improvement of this crop through breeding is limited due to the lack of genetic diversity. Therefore, genetic variability and diversity assessment are necessarily important for the sugarcane clones obtained by FUZZ (True Seed). The experiment was conducted with 47 sugarcane clones at Northern of Côte d'Ivoire (SUCAF CI), Ferkessédougou, during 2015-2016 to 2016-2017, following randomised complete block design (RCBD). Data were collected on different growth and yield contributing traits. %Flowering, Number of stem on 3 meters, stem diameter and %Brix exhibited a high genotypic coefficient of variation and phenotypic coefficient of variation. The medium phenotypic coefficient of variation (PCV) and genotypic coefficient of variation was observed for stem height. Based on the traits studied the stem height, stem diameter and % Brix have a high heritability value estimate excepted a number of stem on 3 meters and %Flowering showed low heritability. Number stem on 3 meters showed a negative correlation with stem diameter and positive correlation with %Brix. It was observed that stem height had a negative correlation with %Brix and positive correlation with %Flowering. Also, it was observed a negative correlation between %Brix and %Flowering. Results indicate that the genotypes should be selected on the basis of a number of stem on 3 meters, %Brix, stem diameter and %Flowering for future selection to get higher sugar yield.
Lucas Aparecido Manzani Lisboa, João Vitor Rodrigues Padovan, Gabriel Banos Rodrigues, Kauê Barbarotto Ribeiro, Gabriel Geminiano da Silva, Hiago Augusto Amaral Sacco, Gustavo Henrique de Oliveira Dias, Leandro Barradas Pereira, Paulo Alexandre Monteiro de Figueiredo
Introduction: In order to characterize Eucalyptus species for diverse purposes, it is necessary to analyze it in an ultrastructural and physiological way, aiming a faster and more precise selection of the possible properties and utilities of the species.
Objective: The objective was to observe the physiological and ultrastructural characteristics of leaves of eucalyptus clones destined for matrix selection.
Materials and Methods: The following clones were used: E54, E20, E24, E45, AEC063 and E16. The following variables were evaluated: CO2 assimilation rate expressed by area (A − μmol CO2 m−2 s−1), transpiration (E − mmol H2O m−2 s−1), stomatal conductance (GS − mol H2O m−2 s−1), internal CO2concentration in the substomata chamber (Ci − μmol mol−1), phloem diameter of leaf (PDL), xylem diameter of leaf (XDL), thickness of palisade parenchyma (PP), abaxial (ABET) and adaxial (ADET) surface thickness, inferior face of stomata functionality (IFFS) and stomata density (SD). Results: The physiological and morphological variations were observed among the clones tested. Conclusion: Clone E16 presented greater leaf transpiration, stomata conductance, the rate of photosynthesis and efficient water use, physiological, palisade parenchyma and stomata functionality. Clone E16 presented lower Adaxial epidermis thickness (AD) and Abaxial epidermal thickness (AB).
The low quality of seedlings can be caused by problems in the irrigation and nutrition of the seedlings in their early stage, thus compromising the success of the implantation of the crop. The aim of this work was to determine the optimal irrigation depth most suitable for the development of cacao tree seedlings genotype TSH1188, raised at different times of the year. To achieve this goal, a study was developed, at the Federal Institute of Espírito Santo - Campus Itapina, about the effect of the application of six different daily irrigation depths (4, 6, 8, 10, 12 and 14 mm) on the growth and quality of seedlings of the cacao genotype TSH1188, produced in tubes, by evaluating the morphological characteristics of the seedlings and their relationship with the quality of the plant. The study was conducted in a completely randomised design (CRD) at three different planting seasons notably in the Autumn with 36 plants per treatment, in the Winter with 20 plants per treatment and the spring using 20 plants per treatment. The results showed that regardless of the season, for all the variables studied, it was discovered that irrigation depths had impacts on the growth and quality of cacao seedlings, the best depths were 8 and 10mm d-1 as the seedlings proved to be the best in all characteristics evaluated. The irrigation depth of 8 mm d-1 was the one that presented the best results for all the three seasons, in the production of cacao tree seedlings genotype TSH1188, i.e. ideal Dickson quality index, stem diameter, plant height and a number of leaves, which are characteristics used to identify quality seedlings.
The Atlantic Forest is considered to be one of the world's most biodiverse wetlands. However, the misuse of natural resources exposes it to physical and biogeographical changes caused by both natural and anthropic disturbances. Consequently, changes in the composition and structure of the remnants forests are expected. Although many studies are performed in this biome, few address the population structure and spatial distribution. The objective of this study was to analyse the spatial distribution pattern and the diametric structure of most representative tree species in a patch of Dense Ombrophilous Forest in the State of Rio Grande do Norte, Brazil. Floristic and parametric vegetation surveys were performed based on quadrants sampling, with 175 sampling points distributed systematically over five transects. At each point, four quadrants were defined, and the living arboreal individual closer to the center of the point, presenting diameter at breast height (DBH) ≥ 3.18 cm, was measured and identified. The Payandeh index was employed to detect the spatial pattern of the species. The diametric structure was analysed by the frequency distribution variation for each species and was estimated by Sturges method. Excluding Coccoloba alnifolia, the other species with high importance value index (IVI) in the forest patch showed an aggregate spatial distribution pattern or a tendency to group. It was observed that the diametric distribution pattern exhibted an inverted-J pattern, with some peculiarities. The study showed an unbalanced distribution for the studied species, but with a tendency to remain in the structural arrangement of the forest, once the human intervention is curbed. Except for C. alnifolia, the other species of higher IVI presented a pattern of aggregate distribution or tendency to aggregate. It was thus possible to understand the behaviour of these plant species of the environment, subsidising actions that aim at the conservation of the studied forest patch.
The establishment of sunflower crop in the Brazilian savannah region depends, among other factors, on the use of cultivars with adaptation to the growing regions and adequate characteristics, such as drought tolerance and resistance to main diseases and early cycle. The objective of this work was to evaluate the agronomic performance of sunflower cultivars sown in the second summer crop in Campo Novo do Parecis (Mato Grosso), the main sunflower producing region in the Brazilian savannah, in 2014 and 2015. The experimental design was a randomised complete block with eight treatments (AGUARÁ 04, AGUARÁ 06, CF 101, GNZ NEON, HELIO 251, MG 305, SYN 045 and SYN 3950HO) and four replications. Sowing was carried out on March 7, 2014, and March 3, 2015. Plant height, head diameter, harvest index, 1000-achene mass, achene productivity, oil content and oil yield were assessed. Data were submitted to analysis of variance and the Scott-Knott test at 5% probability (P < .05). The hybrids AGUARÁ 04, SYN 3950HO, SYN 045, CF 101 and MG 305 stand out for grain and oil yields. AGUARÁ 04 and CF 101 presented the lowest plant height and the highest harvest rate. The hybrid SYN 3950HO has associated high grain and oil yields.