Rafael Resende Finzi

Common scab caused by Streptomyces spp., causes considerable potato yield losses worldwide. Here, we aimed to study the correlation between common scab severity, and soil chemical characteristics and leaf nutrient contents. Data on potato yield, scab incidence, and soil characteristics obtained from 26 sampling points were subjected to multivariate analysis and then analyzed for spatial dependence. For most soil nutrients and pH, there was a inverse relationship with scab severity. Conversely, organic matter, S, Ca, and Mg contents positively correlated with scab damage. Leaf N, P, K, Ca, Mg, S, Cu, Mn, and Fe contents were inversely related severity, whereas B and Zn concentrations were closely associated with the disease. Differences in the relationship between foliar and soil nutrient contents greatly contribute to the complexity with which soil conditions affect the growth of Streptomyces spp. in the soil, and the plant chemical-physiological conditions. Our findings revealed that soil and foliar nutrient status affected the incidence of scab. Although most nutrients suppressed the disease, B and Zn showed a complex association with severity. These discrepancies likely arose from soil conditions, as pH and organic matter drive Streptomyces activity, while plant physiology modulates nutrient uptake and infection resistance.

Devido a importância econômica e à alta demanda nutricional da cultura da batata busca-se cada vez mais por fontes de fertilização capazes de suprir as necessidades da cultura, ao mesmo tempo que se promove um manejo mais sustentável e eficiente. Diante desse cenário, tem se destacado a busca por fontes de fertilização que contenham em sua composição uma fração orgânica, como forma de proporcionar um fornecimento nutricional adequado às culturas, tanto agronomicamente quanto ambientalmente. Dessa forma, o objetivo deste trabalho foi realizar uma revisão da literatura existente sobre o uso de fertilizante organomineral na batata identificando aspectos como origem e importância, fertilização e demandas nutricionais dessa cultura, sustentabilidade dos sistemas agrícolas e fertilizantes organominerais. Buscou-se por dados acadêmicos publicados até 2024 em bases de dados eletrônicos utilizando termos relacionados com organomineral, resíduos e substâncias orgânicas, fertilização em hortaliças, batata e sustentabilidade. Como resultado da revisão, destaca-se que os fertilizantes organominerais demonstram ser uma fonte alternativa de fertilização para o cultivo de hortaliças como a batata por possuir em sua composição uma fração orgânica combinada com fontes minerais. Essa constituição promove uma série de benefícios para toda a cadeia produtiva, desde a fabricação dos fertilizantes até os benefícios para o sistema solo-planta.

The development of mini lettuce genotypes with good agronomic characteristics are fundamental to launch new cultivars. Thus, the objective was to compare the variability of biofortified mini lettuce genotypes by analyzing its principal components and hierarchical clusters and evaluate different selection indices to estimate selection gain. The experiment was carried out at the Federal University of Uberlândia in a randomized block design implemented with 11 treatments (10 genotypes of mini lettuce generation F5:6 and one mini lettuce commercial cultivar) and four repetitions. The following variables were evaluated: chlorophyll content (SPAD índex), stem diameter and length, plant diameter and height, number of leaves per plant, fresh mass of the aerial part, and bolting tolerance. The data were submitted to analysis of variance and genotypes were compared using the Scott-Knott test (P≤0.05). Additionally, principal components, hierarchical clusters, and correlation were evaluated (P≤0.05). The best genotypes were chosen by appropriate direct and indirect selection and the main indices: William’s index, selection index from Smith and Hazel, and Mulamba y Mock index. There were five groups and a significant negative correlation of all agronomic characteristics evaluated with resistance to bolting, except stem length. William’s index provided a balanced distribution of genetic gains by selecting the genotypes UFU 66#8, UFU 215#2, UFU 215#7 and UFU 215#13.

The use of dwarf lines to obtain mini-tomato hybrid plants has led to agronomic and economic advantages. However, the benefits provided by dwarf parents in tomato hybrids of the Santa Cruz type remain unexplored. The aims of this study were to determine the agronomic enhancement in BC1F2 dwarf populations bearing characteristic fruit of the Santa Cruz type after the first backcross and to select populations with high agronomic potential and fruit quality. The experiment was conducted in a greenhouse using a randomized block design with 15 treatments and 4 replicates. Evaluated genetic materials included 11 BC1F2 dwarf tomato populations, both parents (recurrent and donor), and the cultivars (Santa Cruz Kada and Santa Clara). Traits evaluated included: mean weight, soluble solid concentration, number of locules, shape, pulp thickness, fruit longitudinal and transversal diameters, internode length, and plant height. Univariate, multivariate, correlation, and selection index analyses showed that mean fruit weight, transverse diameter, and pulp thickness increased significantly in dwarf populations after a single backcross, most of them exhibiting a fruit shape similar to that of the Santa Cruz type. The dwarf BC1F2 populations UFU-Sci#11 and UFU-Sci#12 showed high potential for obtaining lines and, subsequently, Santa Cruz type hybrids.

Combining broad pest resistance, high yield, and nutritional quality of fruit in the same hybrid is a challenge for round tomato breeders. Thus, development of a dwarf round tomato line for obtaining hybrids may be an excellent alternative for achieving such objectives. The aim of this study was to evaluate the agronomic potential, fruit quality, and pest resistance of BC1F3 dwarf round tomato populations. We evaluated 13 treatments and 4 replications. Treatments consisted of 10 BC1F3 dwarf populations originating from self-fertilization of dwarf populations selected in BC1F2, plus both parents (recurrent and donor) and a commercial hybrid. The traits evaluated were yield, number of fruit, mean weight, number of locules, shape, pulp thickness, longitudinal and transverse diameter of the fruit, precocity index, and soluble solids, β-carotene, lycopene, and acylsugar content. The data were analyzed through the means test. In general, there was an increase of up to 1035% in average fruit weight of the dwarf populations in relation to the donor parent. In addition, some dwarf populations had fruit with 49% more lycopene compared to the commercial hybrid, as well as greater acylsugar content in the leaves (273%). The UFU-DW22 dwarf population stood out with good agronomic potential, higher lycopene content in the fruit, and high acylsugar content, which provides pest resistance. To continue this research, a second backcross is suggested in order to obtain lines and, posteriorly, hybrids with round fruits and compact plants, pest resistance and nutritional quality of fruit.

This study aimed to select promising F2RC1 populations of saladette-type dwarf tomato plants for the development of breeding lines based on agronomic characteristics, fruit quality, and whitefly resistance. The experimental design was randomized blocks containing 13 treatments (10 F2RC1 populations of dwarf tomato plants, both parents, and a commercial hybrid) with four replicates. The evaluations were performed included weight, length, diameter, shape, pulp thickness, number of locules, soluble solids, β-carotene, and lycopene concentration of the fruit; plant internode length; acylsugars concentration; and number of whitefly eggs, nymphs, and adults on the leaflets. The data were analyzed using ANOVA, selection indices, and multivariate analysis. The first backcross increased the agronomic characteristics of the populations in relation to the donor parent, especially for fruit weight (169.1%), fruit length (26.1%), and fruit diameter (16.6%). The UFU SDi 7, UFU SDi 9, and UFU-SDi 17 populations were selected using two selection indices and were therefore considered promising.

The objective of this work was to determine the genetic parameters and the efficiency of different selection indices for biofortified red leaf lettuce (Lactuca sativa var. crispa) lines with agronomic and nutritional potential. The experiment was carried out in a randomized complete block design with three replicates and 31 crisp-textured and red-tinted leaf lettuce genotypes: the Belíssima cultivar, with a low carotenoid content and rich in anthocyanins; and 30 lines from the cross between the Belíssima and Uberlândia 10000 cultivars, rich in carotenoids and with a low anthocyanin content. The assessed traits were: total green mass (g), stem diameter (cm), leaf count, plant diameter (cm), foliar temperature (°C), soil plant analysis development (SPAD) index, anthocyanin content (mg 100 g-1 sample), and bolting (days after sowing). To estimate selection gains, 12 genotypes were selected through selection indices. The traditional index proposed by Smith & Hazel and the sum of ranks index by Mulamba & Mock provided the highest selection gains in the biofortified lettuce. The coefficient of genotypic determination for leaf count, anthocyanin content, bolting, and SPAD index is of high magnitude.

In the improvement of pumpkins, the selection based on one or a few characters of interest tends to be less efficient, leading to a superior product only compared to the few characters selected. To maximize the simultaneous selection of multiple characteristics of interest, selection indexes are used to obtain a numerical value resulting from the combination of the characters on which the simultaneous selection is to be practiced. The objective of this study was to determine genetic parameters and the most appropriate selection indexes in strains of Summer squash (C. pepo). Statistical analyzes were performed based on 65 genotypes belonging to the vegetable germplasm bank of the Federal University of Uberlândia. The variables analyzed were: leaf area index, precocity, SPAD index, productivity. plant-1, number of fruits. Plant-1, leaf temperature, NDVI index and NDRE index. The indexes were used: Smith (1936) and Hazel (1943), the sum of “Ranks” by Mulamba and Mock (1978), and Willians (1962). The selection methodologies selected ten individuals (15% of the genotypes). The values found for h² (%) ranged from 36.92% (SPAD) to 59.65% (cycle). The values obtained in the CVg / CVe quotient were below 1, varying from 0.18 for leaf temperature to 0.70 for the cycle, with the other variables close to 0.5. The CVg genetic variation coefficient (%) was also low, ranging from 1.84% for leaf temperature to 30.94% for productivity. The greatest gains obtained with direct and indirect selection were for the characters productivity (35.92%), NDRE (33.04%), number of fruits (28.93%) and leaf area index (22.72%). The Mulamba and Mock (1978) index showed the highest total selection gain value, providing a balanced distribution of selection gains, choosing the genotypes: 8, 31, 34, 38, 42, 64, 65, 66, 67 and 68.