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Fusarium solani f. sp. cucurbitae (Fsc) is a soil pathogen and the adoption of resistant rootstocks is an effective method of control. Hybrids of Cucurbita spp. are the main rootstock used for watermelon. This study aimed to evaluate the virulence of Fsc race 1 (Fsc1) in three cucurbits and check the reaction of Cucurbita spp. genotypes to the fungus for its use as rootstock. Four experiments were performed. The virulence of Fsc1 in melon, watermelon and Cucurbita spp. was evaluated in experiment I. In experiment two and three the severity of the pathogen in 19 cucurbits was analyzed. And experiment four evaluated the compatibility of these genotypes as a rootstock for watermelon. Cucurbita spp. proved to be more resistant to Fusarium solani f. sp. cucurbitae race 1 than the melon. The high frequency of plants resistant to Fsc1 was found in the genotypes BGC622, BGC620, BGC567, BGC530, BGC186, BGC381, BGC692, BGC082, ES0061 and ES0062. In addition, the evaluated genotypes may be used as watermelon rootstocks, except for the ES530 strain, which was incompatible with the cultivar BRS Opara, but could be used in pumpkin breeding programs, as well as other resistant genotypes. O Fusarium solani f. sp. cucurbitae (Fsc) é um patógeno habitante de solo e a adoção de porta-enxertos resistente é um método efetivo de controle. Os híbridos de Cucurbita spp. constituem o principal porta-enxerto utilizado para melancia. O objetivo desse trabalho foi avaliar a virulência de Fsc raça 1 (Fsc1) em três cucurbitáceas e verificar a reação de genótipos de Cucurbita spp. ao fungo visando seu uso como porta-enxerto. Realizaram-se quatro experimentos. No experimento um, foi avaliado a virulência do Fsc1 em melão, melancia e Cucurbita spp. Nos experimentos dois e três foi analisada a severidade do patógeno em 19 cucúrbitas. E no experimento quatro avaliou a compatibilidade desses genótipos como porta-enxerto para melancia. Cucurbita spp. mostrou-se mais resistente ao Fusarium solani f. sp. cucurbitae raça 1 que o melão. Destacaram-se pela alta frequência de plantas resistentes ao Fsc1 os genótipos BGC622, BGC620, BGC567, BGC530, BGC186, BGC381, BGC692, BGC082, ES0061 e ES0062. Além disso, os genótipos avaliados poderão ser utilizados, como porta-enxerto de melancia, com exceção da linhagem ES530 que se mostrou incompatível com a cultivar BRS Opara, mas poderá ser utilizada em programas de melhoramento de abóbora, assim como os demais genótipos resistentes. &nbsp

The combining ability of six watermelon genotypes was estimated in a diallel cross scheme (6x6), including genotypes JNY (1), ?ORA? (2), ?KOD? (3), ?SOL? (4), ?CHG? (5), ?PEA? (6) and all possible hybrids between them. A randomized complete block design (RCB) was used, with 36 treatments, three blocks, and plots with five plants. The following traits were evaluated: days before female flower anthesis, main branch length, fruit mass, number of fruits per plant, yield, fruit length, fruit width, pulp firmness, soluble solids content, average rind thickness, seed length, seed width, and seed mass. The data obtained were submitted to analysis of variance, and a diallel analysis was performed according to Griffing?s experimental method I. According to the general combining ability estimates obtained, genotypes ?KOD? (3) and ?JNY? (1) were the most likely ones to produce hybrids with smaller-sized fruits and smaller seeds. The reciprocal effects confirmed that the results indicate that these genotypes should be used as pollen donors and pollen recipients, respectively. On the other hand, genotypes ?ORA? (2) and ?CHG? (5) can be used for the commercial exploitation of sliced watermelons. According to the specific combining ability estimates obtained, the combinations ?ORA? (2) x ?PEA? (6), ?ORA? (2) x ?JNY? (1), ?CHG? (5) x ?KOD? (3), ?PEA? (6) x ?KOD? (3), and ?CHG? (5) x ?SOL? (4) stood out as being the genotypes most likely to produce the smallest fruits and smallest seeds. Made available in DSpace on 2022-10-11T18:08:32Z (GMT). No. of bitstreams: 1 Watermelon-general-and-specific-combining-ability-2019.pdf: 333777 bytes, checksum: bb08b0f6e0370b147d8ab84b360aa822 (MD5) Previous issue date: 2019

In order to increase the yield of vegetables of agronomic interest, heterosis has been studied in view of the superiority of hybrids, if compared to genotypes obtained by free pollination. This study aimed to estimate the relative heterosis in watermelon hybrids, regarding the most important agronomic traits, in order to develop future cultivars. The genotypes 'JNY', 'ORA', 'KOD', 'SOL', 'CHG', 'PEA' and all hybrids among them were used, totaling 36 treatments. A randomized block design, with three replications and five-plant plots, was used. The genotypes 'ORA', 'SOL', 'CHG' and 'PEA' were promising for the development of watermelon hybrids with higher weight, whereas 'JNY' and 'KOD' provided combinations with lower fruit weight and smaller seeds, indicating their potential for the development of cultivars of the 'ice box' type. The hybrids 'CHG x ORA' and 'ORA x CHG' were promising to meet the market demand for larger fruits, while 'KOD x JNY' and 'JNY x KOD' could be targeted to the market of smaller fruits. RESUMO Para o aumento da produtividade em hortaliças de interesse agronômico, tem sido realizado o estudo da heterose, devido à superioridade dos híbridos, em relação aos genótipos de polinização livre. Objetivou-se estimar a heterose relativa em híbridos de melancia para os principais caracteres de interesse agronômico, visando ao desenvolvimento de futuras cultivares. Foram utilizados os genótipos 'JNY', 'ORA', 'KOD', 'SOL', 'CHG', 'PEA' e todos os híbridos possíveis entre eles, totalizando 36 tratamentos. Empregou-se o delineamento de blocos casualizados, com três repetições e parcelas com cinco plantas. Os genitores 'ORA', 'SOL', 'CHG' e 'PEA' apresentaram-se promissores para o desenvolvimento de híbridos de maior massa, enquanto 'JNY' e 'KOD' proporcionaram combinações com menor massa de fruto e sementes pequenas, indicando o seu potencial para o desenvolvimento de cultivares do tipo "mini". Os híbridos 'CHG x ORA' e 'ORA x CHG' foram promissores para atender a demanda de mercado por frutos maiores, enquanto 'KOD x JNY' e 'JNY x KOD' podem ser destinados à comercialização de frutos menores.

Climate changes can influence the genetic diversity of forage plants, which may contribute to the improvement and development of new species. Therefore, this research aimed to evaluate the influence of temperature increase on the genetic diversity of Macroptilium accessions based on morphoagronomic descriptors. The experiment was carried out in a growth chamber in a 2×16 factorial arrangement (temperature regimes x Macroptilium accessions), with the temperatures consisting of T1 (20–26–33 °C) and T2 (24.8–30.8–37.8 °C) and 16 accessions. Eleven morphoagronomic descriptors allowed estimating the diversity among accessions. The measurements of genetic dissimilarity enabled us to observe the genetic distance between the studied materials, standing out the accessions T1.M3 and T2.S4 as the most divergent (446.01). The morphoagronomic descriptors percentage of leaves and stem diameter were the most efficient for estimating the diversity between access. Genetic variability points to the adaptation of Macroptilium accessions in the climate change scenario. The accessions more divergent can be explored in genetic breeding programs for the species aiming at the expansion of genetic variability as an adaptation mechanism to heat stress.

Seed sizeis an important agronomic trait and is applicable todifferent abilities. Small seeds guarantee the greater use of the pulp, while larger seeds facilitate sowing. However, there is little work on the genetic control of this characteristicin watermelon. The objective of this work was to study the seed size inheritance in watermelon populations by crossing contrasting genotypes, seeking to gain information to provide technical support during the selection of seed size for the development of new watermelon genotypes. The seed lengths of six populations, P1, P2, F1,F2,BC1and BC2, were measured using the GENES software segregating and nonsegregating generations procedure. This trait is controlled by two genes with incomplete dominance. In addition, depending on the populations studied, inheritance for the characteristicin question may behave differently. Nevertheless, the selection of superior individuals within populations can be performed based on this phenotype, which allows the exploitation of these individuals within breeding programs to develop lines or hybrids. Made available in DSpace on 2020-12-19T09:03:42Z (GMT). No. of bitstreams: 1 Inheritance-of-seed-size-in-watermelon-populations.-2020.pdf: 304006 bytes, checksum: 62acd39045b28b6e83d0b3b609c983ac (MD5) Previous issue date: 2020

O objetivo deste trabalho foi caracterizar morfoagronomicamente folhas e flores de genótipos de Citullus spp. Made available in DSpace on 2018-12-13T00:08:13Z (GMT). No. of bitstreams: 1 Rita1.pdf: 118794 bytes, checksum: b4af9b605ba17b20754cd95c2405d23d (MD5) Previous issue date: 2018-12-12 Edição especial dos Anais do 5 Congresso Brasileiro de Recursos Genéticos, Fortaleza, nov. 2018.

This study aimed to estimate the relative heterosis in watermelon hybrids, regarding the most important agronomic traits, in order to develop future cultivars. Made available in DSpace on 2018-12-13T00:08:37Z (GMT). No. of bitstreams: 1 Rita2018.pdf: 252175 bytes, checksum: d67b21a45820eacd641c1674a8e91719 (MD5) Previous issue date: 2018-12-12