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The selection of native forage species with yield potential under climate change scenarios can strengthen resilience of the Brazilian semiarid region. This study aimed to evaluate the effect of increasing temperature on growth and morphological and yield responses of plants of the genus Manihot. The experimental design was completely randomized in a 2×9 factorial arrangement (two temperature regimes and nine genotypes). The increase in temperature promoted higher plant dry mass (PDM) for genotypes A:24, A:79, A:102, A:EL, and A:GO during establishment. The percentage of leaves was reduced with the highest temperatures in the establishment, except for genotypes A:20, A:21, and A:GO. The increase in temperature during regrowth increased leaf dry mass (LDM) and reduced the leaf to stem ratio, except for A:24, A:79, and A:102, which presented similar values at both temperatures. Species of the genus Manihot respond differently to the 4.8 °C increase in air temperature. The increase in temperature shows a positive impact on the biomass production of species of this genus. Made available in DSpace on 2022-07-11T12:19:38Z (GMT). No. of bitstreams: 1 Rise-in-temperature-increases-2022.pdf: 115482 bytes, checksum: 40a9b59b152841e742be0c021eccf1d5 (MD5) Previous issue date: 2022

The development of cassava (Manihot esculenta Crantz) varieties with greater tolerance of water deficit depends on optimized phenotyping tools. The objective of this work was to develop early prediction models of final root yield (12 months after planting - MAP) using physiological and agronomic data obtained at 4 MAP under two water regimes. Nine genotypes of cassava were evaluated under two treatments (irrigated and with water deficit), using a complete randomized block design, in a factorial scheme of 2 harvest periods (at 4 and 12 MAP) × 9 genotypes, with four replications. Both treatment groups were irrigated until 3 MAP. After this period, irrigation was interrupted for the water deficit treatment group. Fourteen physiological and agronomic traits were evaluated in all harvest periods. Four prediction models were evaluated: linear regression with stepwise selection (LRSS), linear regression with backward selection (LRBS), Bayesian ridge regression (BRR), and partial least squares (PLS). Most of the models presented a high predictive ability for final root yield (R2 ranging from 0.83 to 0.91). However, in all prediction scenarios, the PLS model presented a high R2 (0.84 to 0.91) associated with the lowest root-mean-square error (RMSE) (0.82 to 1.60). Differences in the predictive ability of the models may have occurred due to the relative importance of the early traits. In the case of PLS, the most important traits for the model were stomatal conductance, root yield at 4 MAP, leaf area index and number of roots. Regardless of the water condition, the physiological and agronomic data collected at an early stage could successfully be used to predict the final root yield with great efficiency. This strategy can reduce the cost of phenotyping, increasing the capacity for analysis and optimization of genetic gains for tolerance to drought in cassava. Made available in DSpace on 2019-11-21T18:05:23Z (GMT). No. of bitstreams: 1 Earlypredictionmodelsforcassava2019.pdf: 1484530 bytes, checksum: 6b4d1db1f5a8f5c2d30c51b3fe77e826 (MD5) Previous issue date: 2019

Genetic parameters and genotypic values of fruits from umbu-cajazeira clones were determined using the restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) method, from the morphological, physicochemical and chemical characterization of fruits. The experiment was composed of six experimental clones, in three randomized complete block designs and three replicates per plot in an unbalanced arrangement in Ipanguaçu/RN, due to non-fructification of some clones of the experiment. Morphological, physicochemical and chemical characterization of 20 fruits of each clone was performed. The variance components for REML and medium components (BLUP), were estimated using the mixed model?s method REML/BLUP. The three best clones selected were from Serra do Mel, Açu, and Carnaubais. The method used allowed selection of clones with high soluble solids content and pulp yield based on the genotypic value of clones. Fruit clones from Serra do Mel can be used for pulp processing or fresh consumption. The Açu clone showed a high pulp yield and is recommended pulp processing. Carnaubais, Alto do Rodrigues, and Ipanguaçu generated fruits for fresh consumption. Made available in DSpace on 2018-05-22T00:55:42Z (GMT). No. of bitstreams: 1 Rafaela2018.pdf: 362307 bytes, checksum: 163d2243ec4ed1d85d93b1b9f976343d (MD5) Previous issue date: 2018-05-21

Melon or muskmelon (Cucumis melo L.) is of considerable economic importance in Brazil. Nearly all the cultivars currently grown are hybrids. Heterosis has been used to advantage in the melon plant, and the use of uniform hybrids is one of the reasons for successful cultivation. The aim of the present study was to evaluate the agronomic potential of yellow melon lines and hybrids. An experiment was conducted in randomized blocks with three replications to evaluate 24 hybrids generated by crosses among three elite lines used as female parents (AF-01, AF-02, and AF-03) and eight lines used as male parents (LAM-01, LAM-02, LAM-03, LAM-04, LAM-05, LAM-06, LAM-07, and LAM-08). Yield and fruit quality traits were evaluated. Partial diallel analysis was carried out to estimate general combining ability and specific combining ability. Additive and non-additive effects were observed for the yield, mean fruit weight, and pulp thickness traits. The lines AF-02, LAM-02, and LAM-03 are the most promising as parents as they more frequently have favorable alleles. The most prominent hybrids in diallel analysis were AF-02 x LAM-02, AF-02 x LAM-03, AF-02 x LAM-04, and AF-03 x LAM-06. Made available in DSpace on 2020-03-17T00:38:01Z (GMT). No. of bitstreams: 1 Potentialofparentsandhybridsexperimentaloftheyellowmelon2020.pdf: 1460522 bytes, checksum: fdb9ad7016778c09b32f8a8c7640730b (MD5) Previous issue date: 2020

The aim of this study was to identify sources of resistance to Myrothecium roridum and Podosphaeria xanthii. Initially, 86 inbred lines of the crossing AM-04 x Goldex, 91 inbred lines of the crossing AM-12 x Rochedo, and 75 inbred lines of the crossing ACP x AF-646 were evaluated. The trials were carried out in a greenhouse in a randomized block design with five replications. Seventeen inbred lines were identified as resistant to M. roridum. These inbred lines, as well as the parents and seven differential cultivars (checks) were evaluated for the reaction to P. xanthii. Ten inbred lines were selected as moderately resistant to M. roridum and resistant to P. xanthii

O objetivo do trabalho foi avaliar acessos de Manihot sp. e Macroptilium sp. quanto à tolerância de sementes e plântulas à salinidade. Made available in DSpace on 2019-01-19T23:36:15Z (GMT). No. of bitstreams: 1 Barbara3.pdf: 196794 bytes, checksum: a962ddb9d683e21cdeb1d0acb09a66f5 (MD5) Previous issue date: 2019-01-16 Edição especial dos Anais do 5 Congresso Brasileiro de Recursos Genéticos, Fortaleza, nov. 2018.

This study aimed to characterize buffel grass accessions of the Cenchrus Germplasm Active Bank (CGAB) from Embrapa Semi-Arid in a morphoagronomic way, checking the descriptors variability and efficiency in accessions on two consecutive cuts. Twenty-five accessions and five buffel grass cultivars were used in randomized complete block design with three replications. Evaluations were conducted after two consecutive cuts, each evaluation performed 90 days after each cut. Characterization was based on 15 quantitative and qualitative morphoagronomic descriptors. Quantitative descriptors were subjected to individual and joint univariate analysis of variance, followed by the Scott-Knott?s test at 5% significance. Yet qualitative descriptors were submitted to descriptive analysis. Both quantitative and qualitative descriptors were grouped based on the Gower algorithm for divergence analysis. A dendrogram and calculations of the characters relative importance for divergence were established. Genotype and cutting effects were significant for almost all descriptors in the joint analysis. This result indicates a genetic variability between genotypes and, regarding the cut, it indicates mainly differences in growth rate of each genotype in each cutting season. Genotypes were separated into three groups, which showed good genotype variation. The number of tillers per clump, followed by number of inflorescence and color of seeds, were the most relevant characters in genotype separation.

A Caatinga tem grande potencial forrageiro. Espécies nativas pesquisadas na Embrapa Semiárido demonstram boa qualidade nutricional para compor a dieta dos rebanhos da região

O míldio, causado pelo fungo Pseudoperonospora cubensis é uma das principais doenças foliares que acometem a cultura do meloeiro no período chuvoso da região Nordeste brasileira. O objetivo do presente trabalho foi identificar e caracterizar morfologicamente fontes de resistência de meloeiro a P. cubensis. Trinta e seis acessos e quatro cultivares comerciais foram avaliados em delineamento em blocos casualizados com três repetições. A unidade experimental foi composta por sete plantas. E a avaliação realizada em condições de campo com uma escala diagramática, a qual fora calculado o índice de porcentagem da doença (IPD). As fontes de resistência e genótipos referências foram caracterizadas morfologicamente. Os acessos C-RN-2, C -SE-2, C-CE-2, C-PE-2, C-PI-1 e C-BA-2 apresentam resistência a P. cubensise são promissores para uso em programas de melhoramento visando resistência ao míldio do meloeiro, embora os seus frutos tenham reduzida qualidade comercial.