Depression by inbreeding after four sucessive self-pollination squash generations

The strategy for breeding F1 hybrid squash is to develop parental lines through self-pollination. However, it increases plant mean homozygosis, which is not the natural genetic state of a cross-pollinated species, and can cause "inbreeding depression". The objective of this work was to evaluate this depression with sucessive generations of self-pollination (without selection) in Cucurbita moschata, cv. Piramoita. Populations were obtained from lines with one to four generations of self-pollination (obtained by the SSD method), from the original cv. Piramoita (population S0). Randomized blocks were used with five treatments (different generations of self-pollination - S0 to S4), six replicates and five plants per plot. Regression analysis was made by the Wright inbreeding coefficient (F) to measure the homozygosis level effect on vigor loss. There was a linear reduction of mean weight and fruit length, seed production (number and weight) per fruit with the increase of the homozygosis level; however inbreeding did not affect seed quality (weight of 100 seeds and germination).A estratégia utilizada no melhoramento genético visando híbridos F1 em abóbora é a obtenção de linhagens por autopolinização. Entretanto, a autopolinização aumenta a homozigose média das plantas, que não é a condição genética natural de espécies alógamas, e pode causar a "depressão por endogamia". Este trabalho teve como objetivo verificar se existe depressão por endogamia com sucessivas gerações de autofecundação (sem seleção) em abóbora cultivar Piramoita. Foram obtidas populações a partir da mistura de linhagens com uma a quatro gerações de autofecundação (obtidas pelo método SSD), a partir da população original 'Piramoita' (S0). O delineamento experimental utilizado foi em blocos ao acaso com cinco tratamentos (diferentes gerações de autofecundação - S0 a S4), seis repetições e cinco plantas por parcela. Realizou-se análise de regressão, utilizando-se o coeficiente de endogamia de Wright (F) para medir o efeito do nível de homozigose sobre a perda de vigor. Houve redução linear do peso médio e comprimento de fruto e produção (número e peso) de sementes por fruto com o aumento no nível de homozigose. Entretanto a endogamia não afetou a qualidade das sementes (peso de 100 sementes e germinação)

Seleção para maturidade de bulbos em cebola

It is possible to produce onions (Allium cepa) all over the year in Brazil, but most of the Brazilian cultivars have poor quality bulbs, a fact that favours onion imports from Argentina, a producer of Valenciana type cultivars that does not bulb in Brazil, but please Brazilian consumers. To study the effect of selection for bulb maturity, seventeen half sib progenies selected for early maturity and twenty five for late maturity, from the intervarietal triple cross [Crioula x (Pira Ouro x Valenciana Sintetica 14)] were grown, along with the triple cross itself and the cultivars Pira Ouro (short-day), Crioula (intermediate-day) and Armada (long-day). A total of forty six treatments were tested in a randomized block design with three replications of 32 plants per plot. The progenies selected for earliness had cycles from 67 to 83 days, whereas those selected for lateness had cycles of 85 to 103 days. This difference was evident when comparisons were made for the percent thick neck bulbs, which varied from 0 to 6.2% and from 8.1 to 59.8% for the early and late progenies, respectively. High heritability estimates were obtained for all characters and they varied from 0.65 (thick neck percentage, in the late selection) to 0.80 (average bulb weight, in the early selection). Progenies of higher bulb weight and maturity similar to the standard cultivars were obtained. Selection for maturity was highly efficient and the population selected for early maturity has potential to originate adapted cultivars, with bulb yield and quality superior to the available cultivars.Embora seja possível produzir cebola (Allium cepa) o ano inteiro no Brasil, a maioria dos cultivares nacionais apresentam bulbos com baixa qualidade, o que proporcionou grande importação de cebola da Argentina, do tipo Valenciana, que não bulbifica no Brasil, mas que agradou os consumidores brasileiros. Para estudar o efeito da seleção para maturidade de bulbos baseada em progênies de meios irmãos obtidas do híbrido triplo intervarietal [Crioula x (Pira Ouro x Valenciana Sintética 14)] foram semeadas 17 progênies selecionadas para maturidade precoce e 25 para tardia, além da geração F1 e dos cultivares Pira Ouro (dias curtos), Crioula (intermediários) e Armada (dias longos), totalizando 46 tratamentos. O delineamento foi em blocos ao acaso, com três repetições de 32 plantas por parcela, cultivadas em bandejas de isopor. As progênies precoces apresentaram ciclo médio variando de 67 a 83 dias e as tardias de 85 a 103 dias. Na comparação da porcentagem de plantas improdutivas esta diferença também foi evidente, variando de 0,0% a 6,2% nas precoces e de 8,1% a 59,5% nas tardias. Os coeficientes de herdabilidades obtidos foram elevados, variando de 0,65 (porcentagem de plantas improdutivas, na seleção tardia) a 0,80 (peso médio de bulbo, na seleção precoce), sendo, em média, superiores na população selecionada para maturidade precoce. Foram obtidas progênies com peso de bulbo superior às testemunhas 'Pira Ouro' e 'Crioula' e com ciclo que não diferia destas. A seleção para maturidade foi altamente eficiente e a população selecionada para maturidade precoce apresenta grande potencial de originar cultivares adaptados, com produção e qualidade de bulbos superiores às disponíveis no mercado brasileiro

Sulfur doses, organic compost and gypsum in macronutrients contents of collard greens leaves

Due to the lack of information related to fertilization of collard greens, the objective of the research was to evaluate the influence of sulfur doses in macronutrients contents in collard greens cultivated with organic compost and gypsum. Twelve treatments were evaluated in a split-plot: three types of soil preparation in plots and four sulfur doses top dressing in subplots. The three types of soil preparation were the incorporation of organic compost (30 t ha-1); gypsum (1.2 t ha-1); organic compost (30 t ha-1) plus gypsum (1.2 t ha-1). The total sulfur doses in top dressing were zero; 53.32; 106.68 and 160.00 kg ha-1 of S, equivalent to 0; 266; 532 and 800.0 kg ha-1of ammonium sulfate. For standardization of the nitrogen dose (280 kg∙ha-1), applied in top dressing it was used urea. From the dry matter of commercial leaves, it was evaluated the N, P, K, Ca, Mg and S contents. The types of soil preparation do not affect all macronutrients content. The sulfur top dressing applied does not alter the contents of leaf macronutrients N, P, K and Ca on collard greens cultivated with organic compost and gypsum. The sulfur content presents a linear increase, while for the magnesium content there is decrease the higher the sulfur doses. The decreasing order of macronutrient content of commercial collard greens leaves was K> N> Ca> Mg> S> P, with averages 37.92, 36.50, 21.69, 4.50, 4.23, 3.80 g kg-1, respectively.  Due to the lack of information related to fertilization of collard greens, the objective of the research was to evaluate the influence of sulfur doses in macronutrients contents in collard greens cultivated with organic compost and gypsum. Twelve treatments were evaluated in a split-plot: three types of soil preparation in plots and four sulfur doses top dressing in subplots. The three types of soil preparation were the incorporation of organic compost (30 t ha-1); gypsum (1.2 t ha-1); organic compost (30 t ha-1) plus gypsum (1.2 t ha-1). The total sulfur doses in top dressing were zero; 53.32; 106.68 and 160.00 kg ha-1 of S, equivalent to 0; 266; 532 and 800.0 kg ha-1of ammonium sulfate. For standardization of the nitrogen dose (280 kg∙ha-1), applied in top dressing it was used urea. From the dry matter of commercial leaves, it was evaluated the N, P, K, Ca, Mg and S contents. The types of soil preparation do not affect all macronutrients content. The sulfur top dressing applied does not alter the contents of leaf macronutrients N, P, K and Ca on collard greens cultivated with organic compost and gypsum. The sulfur content presents a linear increase, while for the magnesium content there is decrease the higher the sulfur doses. The decreasing order of macronutrient content of commercial collard greens leaves was K> N> Ca> Mg> S> P, with averages 37.92, 36.50, 21.69, 4.50, 4.23, 3.80 g kg-1, respectively

Comportamento de gerações avançadas de um híbrido de pepino japonês

Inbreeding reduces the vigor in plants as a result of a decrease in the proportion of heterozygous loci. However, the influence of inbreeding is different among the species. The objective of this work was to evaluate the inbreeding depression in a cucumber Japanese population. An F2 population was obtained from a commercial hybrid (Natsu suzumi), which was considered as S0 population. S1, S2, S3, S4 and S5 progenies were obtained by the 'Single Seed Descent' methodology. A complete blocks design with seven treatments (different generations of self pollination - S0 to S5 and the hybrid Natsu suzumi), and six replications of five plants per plot was used in protected cultivation from Aug. 21 to Nov. 29, 2002. Number of leaves, length of the main stem, number and weight of fruits (total and commercial) number of nodes and vines percentage were evaluated. For most of the traits appraised differences were not observed among populations showing that there was no loss of vigor due to inbreeding in this population.A endogamia reduz o vigor em plantas pela diminuição da proporção de loci heterozigotos. Entretanto, a influência da endogamia é diferente entre as espécies. O objetivo deste trabalho foi avaliar a depressão causada por endogamia em uma população de pepino do tipo japonês. A partir do intercruzamento entre plantas do híbrido Natsu suzumi foi obtida a geração F2, considerada como população S0. Obtiveram-se progênies S1, S2, S3, S4 e S5, através de autofecundações sucessivas pelo método do SSD ('Single Seed Descent'). Foram sete tratamentos (híbrido Natsu suzumi, populações S0 a S5) e o delineamento experimental foi em blocos ao acaso, com seis repetições e cinco plantas por parcela cultivadas em ambiente protegido de 21/08/2002 à 29/11/2002. Foram avaliados o número de folhas, semanalmente, o número e a massa de frutos, total e comercial, número de nós e porcentagem de nós com brotações laterais. Na comparação entre as populações S0 a S5 não foram observadas diferenças para todas as características avaliadas demonstrando não haver perda de vigor por endogamia nesta população

Performance of advanced generation from a hybrid Japanese cucumber

Inbreeding reduces the vigor in plants as a result of a decrease in the proportion of heterozygous loci. However, the influence of inbreeding is different among the species. The objective of this work was to evaluate the inbreeding depression in a cucumber Japanese population. An F2 population was obtained from a commercial hybrid (Natsu suzumi), which was considered as S0 population. S1, S2, S3, S4 and S5 progenies were obtained by the 'Single Seed Descent' methodology. A complete blocks design with seven treatments (different generations of self pollination - S0 to S5 and the hybrid Natsu suzumi), and six replications of five plants per plot was used in protected cultivation from Aug. 21 to Nov. 29, 2002. Number of leaves, length of the main stem, number and weight of fruits (total and commercial) number of nodes and vines percentage were evaluated. For most of the traits appraised differences were not observed among populations showing that there was no loss of vigor due to inbreeding in this population.A endogamia reduz o vigor em plantas pela diminuição da proporção de loci heterozigotos. Entretanto, a influência da endogamia é diferente entre as espécies. O objetivo deste trabalho foi avaliar a depressão causada por endogamia em uma população de pepino do tipo japonês. A partir do intercruzamento entre plantas do híbrido Natsu suzumi foi obtida a geração F2, considerada como população S0. Obtiveram-se progênies S1, S2, S3, S4 e S5, através de autofecundações sucessivas pelo método do SSD ('Single Seed Descent'). Foram sete tratamentos (híbrido Natsu suzumi, populações S0 a S5) e o delineamento experimental foi em blocos ao acaso, com seis repetições e cinco plantas por parcela cultivadas em ambiente protegido de 21/08/2002 à 29/11/2002. Foram avaliados o número de folhas, semanalmente, o número e a massa de frutos, total e comercial, número de nós e porcentagem de nós com brotações laterais. Na comparação entre as populações S0 a S5 não foram observadas diferenças para todas as características avaliadas demonstrando não haver perda de vigor por endogamia nesta população

Coincidência de florescimento entre linhagens de couve-flor na produtividade e qualidade de sementes híbridas

The missing of flowering synchronization between the self-incompatible lines in a crop field of cauliflower hybrid seeds besides making the seed production smaller can compromise the genetic purity of them. The coincidence of the flowering time between two cauliflower lines was examined to study its effect on the productivity and quality of hybrid seeds. The treatments consisted of six different sowing dates, every fifteen days, using a self-incompatible tropical line pollinated by a winter line which does not present self-incompatibility. The following characteristics were evaluated: leaf average area and number of flowers per plant, number of siliques per plant, number and weight of seeds per plant, weight of thousand seeds and average number of seeds per silique. The germination standard test and genetic seed purity were determined for each treatment. The coincident flowering season between cauliflower lines affects directly the productivity and the genetic quality of the produced hybrid seeds. The closer the flowering time coincidence between the lines, the greater the number of seeds per silique and the smaller the percentage of non-hybrid seedlings. However, the coincidence of the flowering season between lines was found to influence physiological seed quality.A falta de sincronismo de florescimento entre as linhagens auto incompatíveis em um campo de produção de sementes híbridas de couve flor pode além de reduzir a produção de sementes comprometer a pureza genética das mesmas. Com o objetivo de estudar o efeito da coincidência de florescimento entre linhagens de couve-flor na produtividade e qualidade de sementes híbridas, foi realizado o presente experimento. Os tratamentos consistiram em seis diferentes épocas de semeadura, espaçadas a cada quinze dias, de uma linhagem de verão auto-incompatível que foi polinizada por uma linhagem de inverno que não apresenta auto-incompatibilidade. Observou-se a coincidência do florescimento das diferentes épocas de semeadura com a linhagem polinizadora. Foram avaliadas as seguintes características: área foliar média, número de flores por planta, número de síliqüas por planta, número de sementes por planta (peso e número), peso médio de 1000 sementes e foi determinado o número de sementes por síliqüa. Foi realizado ainda, o teste padrão de germinação e determinada a pureza genética das sementes para cada tratamento. A coincidência da época de florescimento entre as linhagens de couve-flor afetou diretamente a produtividade e a qualidade genética das sementes híbridas produzidas, sendo que, quanto maior foi o nível de coincidência, maior foi o número de sementes formadas por síliqüa e menor a percentagem de sementes contaminantes. Entretanto, não teve influência na qualidade fisiológica das mesmas

QUALITY OF CAMBUCI PEPPER SEEDLINGS IN RESPONSE TO THE APPLICATION OF NUTRIENT SOLUTIONS

One of the main stages in the production system of a crop is the production of quality seedlings since it influences the plants' final performance in the field and their production. The study aimed to evaluate different nutrient solutions in the production of Cambuci pepper seedlings. The design used was a complete randomized design, with six treatments corresponding to the nutrient solutions proposed for the pepper crop by Castellane and Araújo, Claudio Roberto, Hoagland, and Arnon, besides the commercial products Plenan® and Biobokashi®, and a control treatment without fertilization, with six replications. The final evaluation was carried out 45 days after sowing. The following variables were analyzed: stem diameter, plant height, leaf dry matter, shoot dry matter, the number of leaves, relative chlorophyll index ("Spad"), and Dickson quality index. The seedlings subjected to the applications of Claudio Roberto and Hoagland and Arnon solutions have the highest heights and number of leaves, the largest stem diameter, shoot dry matter, leaf area, and Dickson quality index with 2.60 and 2.51 mm, 0.54 and 0.62 g, 38.64 and 41.91 cm2, and 0.107; 0.097, respectively. The Hoagland and Arnon nutrient solution provided the best characteristics to produce Cambuci pepper seedlings

Rendimiento de achicoria ‘Folha larga’ y ‘Pão de açúcar’ en función de la densidad de plantación

1 recurso en línea (páginas 322-328) : ilustraciones color.La densidad de planta influye directamente en el potencial productivo de los cultivos y la mejor puede no ser la misma para todos. Debido a la falta de investigación en esta línea con achicoria, con el objetivo de estudiar el efecto de la densidad de plantas sobre el rendimiento de los dos cultivares de achicoria, de Folha Larga y Pão de Açúcar. Se evaluaron siete densidades de plantas (444.444, 370.370, 333.333, 277.778, 266.667, 222.222 y 185.185 plantas/ha), en un diseño de bloques al azar con cuatro repeticiones. Se evaluaron el peso fresco, altura de planta, número de hojas y la rendimiento. A pesar de la densidad no influyó en altura de la planta, había una disminución en el peso fresco y el número de hojas por planta y hubo un aumento de la rendimiento de los dos cultivares de mayor densidad.Plant density directly influences the productive potential of crops, and the best density is not the same for all cultivars. Because of a lack of research in this area with chicory, this study aimed to evaluate the effect of plant density on the production of two chicory cultivares, Folha Larga and Pão de Açúcar. Seven planting densities were evaluated (444,444; 370,370; 333,333; 277,778; 266,667; 222,222 and 185,185 plants/ha); the experiment design used a randomized block design with four replications. The fresh weight, plant height, leaf number and yield were evaluated. Despite the fact that density did not influence plant height, mass reduction was observed in the fresh weight and number of leaves per plant and there was an increase in yield of both cultivars with the higher density.Bibliografía: páginas 327-328

Parsley production using organic fertilizers before planting and in top dressing

The objective of this research was to evaluate the effect of two organic fertilizers used before planting and in top dressing in the production of parsley. Seven treatments were evaluated, resulted from the factorial 2 x 3 + 1: two organic fertilizers (castor bean cake, and hoof and horn powder) x 3 modes of application (100% before planting; 100% in top dressing; 50% before planting and 50% in top dressing) + 1 control. The experimental design was in randomized blocks, with five replications and plots of 1 m2. Two harvests were done and in both the following characteristics were evaluated: the relative chlorophyll index ("Spad''), plant height, fresh (FW) and dry (DW) matter weight of shoot and macronutrients accumulation. There was no significant difference for the ‘’Spad” index in both harvests. For the other characteristics, the control was inferior to the other treatments. In the comparison among application modes, the treatment with castor bean cake, 100% before planting, was inferior to the other applications modes of this fertilizer for FW and DW. For hoof and horn powder, the 100% in top dressing application mode was superior to other applications. In the comparison between fertilizers, the hoof and horn powder was superior to castor bean cake in both harvests when application was done 100% before planting. The descending order of macronutrients accumulation was: K > N > Ca > P > Mg. Therefore, it is recommended to apply hoof and horn powder, 100% in top dressing application.The objective of this research was to evaluate the effect of two organic fertilizers used before planting and in top dressing in the production of parsley. Seven treatments were evaluated, resulted from the factorial 2 x 3 + 1: two organic fertilizers (castor bean cake, and hoof and horn powder) x 3 modes of application (100% before planting; 100% in top dressing; 50% before planting and 50% in top dressing) + 1 control. The experimental design was in randomized blocks, with five replications and plots of 1 m2. Two harvests were done and in both the following characteristics were evaluated: the relative chlorophyll index ("Spad''), plant height, fresh (FW) and dry (DW) matter weight of shoot and macronutrients accumulation. There was no significant difference for the ‘’Spad” index in both harvests. For the other characteristics, the control was inferior to the other treatments. In the comparison among application modes, the treatment with castor bean cake, 100% before planting, was inferior to the other applications modes of this fertilizer for FW and DW. For hoof and horn powder, the 100% in top dressing application mode was superior to other applications. In the comparison between fertilizers, the hoof and horn powder was superior to castor bean cake in both harvests when application was done 100% before planting. The descending order of macronutrients accumulation was: K > N > Ca > P > Mg. Therefore, it is recommended to apply hoof and horn powder, 100% in top dressing application