Resumo: O objetivo deste trabalho foi avaliar cinco índices de seleção não paramétricos para a seleção de citros híbridos como porta-enxertos, enxertados com laranjeira 'Valência', com base em atributos horticulturais relevantes para a indústria de processamento de suco. Avaliaram-se 46 porta-enxertos em delineamento de blocos ao acaso, com três repetições e cinco plantas na parcela, no período de 2009-2015, em cultivo de sequeiro. As médias das variáveis altura de planta, produção acumulada de frutos, eficiência produtiva de frutos, concentração de sólidos solúveis totais, rendimento de suco e tolerância à seca foram utilizadas para calcular os seguintes índices: multiplicativo (IEi), soma de classificação (IMMi), distância genótipo-ideótipo (DiI) e ranqueamento (IRKi, baseado em médias simples; e IRKii, baseado em normalização linear). Os índices foram eficientes em classificar os híbridos em relação ao desempenho geral. A correlação de Spearman mostrou alta similaridade entre a maioria dos índices não paramétricos, notadamente entre IRKi e IRKii. Os índices de ranqueamento, principalmente o IRKii, fornecem uma classificação mais coerente dos híbridos, o que permite a seleção de porta-enxertos mais produtivos e tolerantes à seca, para a produção de frutas de alta qualidade para processamento.

Abstract: The objective of this work was to evaluate five nonparametric selection indices for the selection of hybrid citrus rootstocks grafted with 'Valência' sweet orange, using horticultural traits relevant for the juice processing industry. Forty-six rootstocks were evaluated in a randomized complete block design, with three replicates and five trees in the plot, in the period from 2009-2015, in a rainfed cultivation. The means of the variables plant height, accumulated fruit yield, fruit yield efficiency, total soluble solids concentration, juice yield, and drought-tolerance were used to calculate the following indices: multiplicative index (IEi), sum of classification (IMMi), genotype-ideotype distance (DiI), and ranking indices (IRKi, based on simple means; and IRKii, based on linear normalization). The indices were efficient to classify the hybrids in relation to general performance. Spearman’s correlation showed a high similarity between most nonparametric indices, notably between IRKi and IRKii. The ranking indices, mainly IRKii, provide a more coherent classification of the hybrids, which allows of the selection of more productive and drought-tolerant rootstocks to produce high-quality fruit for processing.

Abstract Citrus plants have a long juvenile period, which has hampered the breeding progress of these species. In this sense, research focused on reducing the juvenile phase is needed to accelerate the breeding process. In this study, the morphology of the hybrid {[(‘Rangpur’ lime) x YMCT (‘Yuma’ citrange) - 005] x (Microcitrus papuana) - 001} (H011), which has a short juvenile period, and the gene expression levels of the FLOWERING LOCUS T (FT) were evaluated. Morphological studies indicated early flowering and fruiting of the hybrid, characteristics that make it a promising candidate for citrus breeding. In addition, winter temperatures influenced the expression of the FT gene in stems and leaves.

ABSTRACT: Rootstocks influence certain characteristics of the scion, such as vigor, fruit yield and quality, and tolerance to biotic and abiotic factors. In conventional citrus breeding programs, hybridization is the main method used for obtaining rootstock varieties. Between Sept and Oct 2006, controlled pollinations were carried out resulting in nine progenies, totaling 461 hybrid seedlings. The female parents were the ‘Santa Cruz Rangpur’ lime (SCRL) and the ‘Sunki of Florida’ mandarin (SFM), while the male parents, in addition to this mandarin, were the ‘Indio’ and ‘Riverside’ citrandarins, the ‘Thomasville’ citrangequat (THOM), the ‘Swingle’ citrumelo, the ‘Argentina’ citrange (AGC) and the ‘Benecke’ trifoliate orange (BKTO). Fruit setting rates of these crosses were measured and the hybrids generated were planted in the field in 2008 and evaluated from 2010 to 2014, for the variables of plant mortality, visual vigor, plant height and trunk diameter. The descriptive statistics mean, variation range, coefficient of variation and Pearson skewness coefficient were calculated. Data were submitted to analysis of variance and the means of the treatments were grouped by the Scott-Knott test, both at 5 % significance. The progenies, having the ‘Sunki’ mandarin as the female parent, presented higher fruit setting rates and lower plant mortality rates than those obtained from the female parent ‘Rangpur’ lime, while zero plant mortality was observed in the SFM × BKTO cross. The crosses SCRL × SFM, SFM × BKTO, SFM × AGC and SFM × THOM have the potential to generate vigorous hybrids, resulting in rootstock varieties adapted to the landscape unit of Coastal Tableland.

Abstract The aim of this study was to develop a methodology that uses water deficit induction to increase the frequency of hybrids in Citrus varieties that have a high and an intermediate level of polyembryony, respectively. The experiment examined the ‘Sunki Tropical’ mandarin and ‘Rangpur Santa Cruz’ lime genotypes at three water stress intensities: 20, 40 and 100% of the pot capacity (PC). The generated fruits were harvested, and the seeds were counted. After germination, the number of nucellar and hybrid seedlings was determined. For ‘Rangpur Santa Cruz’ lime genotype, the highest hybrid frequency generated was 64.2%, which occurred at a PC of 40% and exceeded by 12% that occurring at a PC of 100%. For ‘Sunki Tropical’ mandarin, the highest observed hybrid frequency was 21.75%, which occurred at a PC of 20% and was more than double the hybrid frequency of 8.57% observed at 100% of the PC.

Resumo Na Bahia, a produção de citros é concentrada no Litoral Norte, com cultivo predominante da laranjeira ‘Pera’ enxertada em limoeiro ‘Cravo’. A produção de tangerinas é muito baixa, apesar do consumo regional crescente. Variedades adaptadas ao clima tropical subúmido devem ser avaliadas em combinação com diferentes porta-enxertos visando à recomendação de cultivo. Neste estudo, o desempenho do tangor ‘Piemonte’ foi avaliado sobre 14 porta-enxertos em Rio Real-BA. O experimento foi instalado a campo em 2006, em um Argissolo Amarelo coeso, no espaçamento 6,0 m x 4,0 m, sem irrigação. O crescimento de planta, a produção e os atributos físico-químicos de frutos foram avaliados em 2010-2014, além da sobrevivência de árvores e a tolerância à seca com base no enrolamento foliar. Aos nove anos de idade, os porta-enxertos que induziram maior produção acumulada foram os citrandarins ‘Riverside’ e ‘Indio’, o limoeiro ‘Cravo Santa Cruz’ e as tangerineiras ‘Cleópatra’, ‘Sunki Tropical’ e ‘Sunki Maravilha’. Embora quatro porta-enxertos, híbridos tenham sido semiananizantes, sua eficiência foi semelhante à dos demais (˜ 5,5 kg m-3), resultando na menor produção. A tolerância à seca e a sobrevivência foram similares entre os porta-enxertos com perda mínima de plantas, à exceção de TSKFL x CTSW - 049, com apenas 33.33% de plantas vivas. Em geral, o tangor ‘Piemonte’ produziu frutos com boa qualidade nas condições avaliadas, e apenas a espessura da casca e o índice tecnológico (IT) foram influenciados pelos porta-enxertos, com menores médias de IT sobre TSKC x (LCR x TR) - 001 e limoeiro ‘Volkameriano’.

Abstract In the state of Bahia, Brazil, citrus production is mainly on the Northern Coast region, with major cultivation of ‘Pera’ sweet orange grafted onto ‘Rangpur’ lime. The production of mandarins and mandarin-like fruits is very low in spite of the increasing regional consumption. Varieties that are adapted to tropical sub humid conditions should be evaluated on different rootstocks for cultivation recommendation. This study assessed the performance of ‘Piemonte’ tangor over 14 rootstocks in Rio Real, BA. Planting was performed in 2006 on a cohesive yellow argisol, at 6.0 m x 4.0 m spacing and with no irrigation. Plant growth, production, and physicochemical attributes of fruits in 2010-2014 were assessed, in addition to tree survival and drought tolerance based on leafroll. At nine years of age, rootstocks that induced greater cumulative production of ‘Piemonte’ were ‘Riverside’ and ‘Indio’ citrandarins, ‘Santa Cruz Rangpur’ lime, and ‘Cleopatra’, ‘Sunki Tropical’ and ‘Sunki Maravilha’ mandarins. Although four hybrid rootstocks were semidwarfing, their mean efficiency was equivalent to the other rootstocks (˜ 5.5 kg m-3), resulting in the lowest production. Drought tolerance and tree survival were similar among rootstocks with minimal loss, except for TSKFL x CTSW - 049 hybrid with only 33.33% of survival. ‘Piemonte’ tangor produced fruits with general good quality under the evaluated conditions, but only peel thickness and technological index (TI) were influenced by rootstocks, with the lowest TI averages recorded for fruits harvested from scions grafted onto TSKC x (LCR x TR) - 001 and ‘Volkamer’ lemon.

Resumo A diversificação de variedades-copa e porta-enxerto é altamente necessária à citricultura no Nordeste do Brasil. Avaliou-se o desempenho inicial de 13 variedades de laranjeira-doce enxertadas em citrandarineiro ‘San Diego’, além da laranjeira-de-umbigo ‘Cara Cara’ e da limeira-ácida ‘Tahiti CNPMF-02’ sobre diversos porta-enxertos, em Inhambupe, no Litoral Norte do Estado da Bahia. Três experimentos foram conduzidos separadamente, sendo o plantio realizado em 2008, no espaçamento de 6,0 m x 3,0 m, com irrigação suplementar. Avaliaram-se tamanho da planta, produção e qualidade dos frutos nas três safras iniciais. As laranjeiras ‘Aquiri’, ‘Biondo’, ‘Agridoce’, ‘Kona’, ‘Pineapple’, ‘Russas CNPMF-03’ e ‘Salustiana’ acumularam maior produção de frutos no período. As laranjeiras ‘Pera CNPMF D-6’, ‘Westin CNPMF’ e ‘Salustiana’ apresentaram frutos com poucas sementes, sendo apropriadas ao mercado in natura, além da maior eficiência de produção da copa da primeira. Apesar de a ‘Westin CNPMF’ apresentar boa qualidade de frutos, sua produção inicial foi menor. Os limoeiros ‘Rugoso da Flórida’ e ‘Volkameriano’ induziram maior produção acumulada à laranjeira ‘Cara Cara’. O tamanho das árvores e a qualidade dos frutos não foram influenciados pelos porta-enxertos avaliados. A tangerineira ‘Cleópatra’ e o citrandarineiro ‘Riverside’ determinaram à limeira-ácida ‘Tahiti CNPMF-02’ maiores volumes de copa, produção acumulada e tamanho de frutos. Todas as combinações apresentadas acima de copa e porta-enxerto apresentam potencial para cultivo no Litoral Norte da Bahia, sendo alternativas à combinação predominante, laranjeira ‘Pera’ enxertada em limoeiro ‘Cravo’.

Abstract The diversification of scion and rootstock varieties is tremendously necessary for the citrus industry in Northeastern Brazil. The initial performance of 13 sweet orange varieties grafted onto ‘San Diego’ citrandarin, and of ‘Cara-Cara’ navel orange and ‘CNPMF-02 Persian’ lime grafted onto several rootstocks was evaluated in the municipality of Inhambupe, northern coast of the state of Bahia. Three trials were carried out separately, and tree size, fruit production and quality were assessed in the first three crops, with planting in 2008 at 6.0 m x 3.0 m spacing with supplemental irrigation. ‘Aquiri’, ‘Biondo’, ‘Agridoce’, ‘Kona’, ‘Pineapple’, ‘Russas CNPMF-03’ and ‘Salustiana’ sweet oranges showed the largest cumulative production in the first three crops. ‘Pera CNPMF D-6’, ‘Westin CNPMF’ and ‘Salustiana’ sweet oranges had fewer seeds per fruit, being more appropriate for fresh fruit market, in addition to greater production efficiency for the first one. Although ‘Westin CNPMF’ has shown good fruit quality, its initial production was low. ‘Florida’ rough lemon and ‘Volkamer’ lemon induced higher cumulative production compared to ‘Cara Cara’ navel orange, but tree size and fruit quality were not influenced by any evaluated rootstock. ‘Cleopatra’ mandarin and ‘Riverside’ citrandarin led to higher tree size and cumulative production and heavier fruits of ‘CNPMF-02 Persian’ lime. All scion and rootstock combinations have potential for cultivation on the northern coast of the state of Bahia and appear as an alternative to the prevalent ‘Pera’ sweet orange on ‘Rangpur’ lime combination.

ABSTRACT ‘Persian’ lime (PL) [Citrus latifolia (Yu. Tanaka) Tanaka] is an important species both for domestic fresh fruit consumption in Brazil as well as the export market, since the country is one of the largest producers in the world despite the fact that, in commercial plantations, it is still not uncommon to find trees with low productivity and high plant vigor of unknown origin. Selections of Persian lime ‘CNPMF–2000’, ‘CNPMF–2001’, ‘CNPMF–01’, ‘CNPMF–02’, ‘IAC–5’, ‘IAC–5.1’, ‘Bearss’, ‘Persian–58’, and ‘5059’, were therefore grafted onto Swingle citrumelo [C. paradisi Macfad. cv. Duncan × Poncirus trifoliata (L.) Raf.] rootstocks and evaluated in Cruz das Almas, Bahia, Brazil in a field experiment conducted in a completely randomized block design with five replications and two trees per plot. The biometric attributes (canopy height, diameter and volume), yield parameters (yield during the off-season harvest period, yield per plant, production efficiency), and fruit quality traits, were evaluated. The ‘CNPMF–2001’, ‘CNPMF–01’, ‘CNPMF–02’, ‘IAC–5’, and ‘Bearss’ selections had 5-11 % shorter trees than the other cultivars. ‘CNPMF–01’, ‘CNPMF–02’, ‘Persian–58’, and ‘5059’ presented higher yield efficiency values, between 3.1-3.4 kg m−3, and higher yield levels during the off-season harvest periods. The ‘Bearss’, ‘Persian–58’, ‘CNPMF–2000’, ‘IAC–5.1’ and ‘5059’ selections had more acid fruits and the latter three, smaller fruits. Based on their horticultural performance up to eight years of age, ‘CNPMF–01’, ‘CNPMF–02’, ‘Persian–58’ and ‘5059’ selections were the most promising varieties of Persian lime.

The genetic reduction of linolenic acid levels increases the quality and stability of soybean oil. The objective of this study was to determine the inheritance and evaluate the nature and magnitude of gene effects on soybean seed linolenic acid level. Means and variances of F1, F2, and F3 generations were made from the cross between accession BARC-12 (low linolenic acid content) and the commercial Brazilian cultivar CAC-1 (normal linolenic acid content). The results demonstrated that linolenic acid content in soybean is under the genetic control of a small number of genes. The additive model explained the means for the three generations and for the parents. Non-allelic gene interactions had little effect on the determination of genotypic values for the individuals. The generation means and population variation analyses demonstrated that the dominance deviations contribute little to the trait. These results showed that backcross breeding programs can be used to introduce the low linolenic acid content trait into soybean seeds, since it is possible to identify with very high accuracy the desired genotypes in segregating populations.