Joint Analysis Of Variance Research Articles

Avaliação de progênies f2:4 e f4:6 de soja e perspectivas do uso de teste precoce para a produção de grãos

Este trabalho teve como objetivo verificar as perspectivas do uso da seleção precoce para a produção de grãos no melhoramento genético da soja. Para isso, obteve-se uma população de soja, derivada do cruzamento entre as linhagens 14 e 38, divergentes para a produção de grãos, de onde foram extraídas 100 progênies F2:4 e 100 progênies F4:6. Estas foram avaliadas experimentalmente no ano agrícola de 2006/2007, utilizando o delineamento em látice com quatro repetições, e em dois locais, no município de Piracicaba (SP). As parcelas foram constituídas de uma linha de 2 m de comprimento, espaçadas de 0,5 m, contendo 35 plantas após o desbaste. A partir das análises de variância conjuntas da produção de grãos das gerações F2:4 e F4:6 foram estimados os componentes de variância, os coeficientes de herdabilidade entre médias de progênies e as respostas esperadas com seleção. As respostas esperadas com seleção foram cerca de 60% superiores na geração F4:6; entretanto, o tempo para completar um ciclo seria maior, o que compensaria esta superioridade. Os resultados indicam que a seleção precoce pode ser eficiente em soja, desde que aplicada com intensidades moderadas.

Desempenho agronômico de linhas endogâmicas recombinadas de pimenta em dois sistemas de cultivo

As diversidades de clima e de manejo interferem no desenvolvimento e na produtividade vegetal, uma vez que essas características estão diretamente correlacionadas ao genótipo e ao ambiente de cultivo. Neste estudo, o objetivo foi estimar os efeitos do tipo de manejo sob o desempenho agronômico de 12 linhas endogâmicas recombinadas (F7) de pimenta (Capsicum annuum L.), originadas do cruzamento entre um acesso de pimentão suscetível à mancha-bacteriana (UENF 1421) e um acesso de pimenta resistente (UENF 1381). Dois experimentos foram conduzidos, sendo um deles em condições de campo, em Campos dos Goytacazes, RJ e o outro em sistema orgânico e cultivo protegido, em Seropédica, RJ. Foram avaliados o número total de frutos (NTF), peso total de frutos (PTF), peso médio dos frutos (PMF), comprimento dos frutos (CF), diâmetro dos frutos (DF), relação comprimento/diâmetro do fruto (CF/DF) e a presença de capsaicina (CAPS). Foram realizadas a análise conjunta e o estudo da decomposição da interação genótipo x ambiente (G x A). Estimaram-se os componentes quadráticos genotípico e da interação G x A, o coeficiente de determinação genotípico e de variação genético e do índice de variação. A interação G x A foi significativa para o número, o peso total e médio de frutos, além do diâmetro do fruto e da relação comprimento/diâmetro. Com exceção do comprimento do fruto, o cultivo protegido e orgânico propiciou melhores médias para todas as características estudadas. Os parâmetros estudados mostraram que as causas de variação foram devidas às diferenças genéticas existentes entre as linhas e que o peso total de frutos foi a característica mais influenciada pelo manejo empregado. Entre as linhas pungentes, no cultivo em campo, a linha 2 mostrou alta capacidade produtiva e, para o cultivo protegido, a linha 8 obteve o maior número de frutos. Entre as não-pungentes, a linha 1 foi superior em ambos os ambientes.

ESTABILIDADE PRODUTIVA DE HÍBRIDOS E VARIEDADES DE MILHO NO MEIO-NORTE BRASILEIRO

Twenty-four maize cultivars (21 varieties and three hybrids) were evaluated in twelve environments of the Middle-North Region of Brazil (six in Piaui and six in Maranhao), in the 2000/2001 and 2001/2002 growing seasons, aiming to obtain regionally adapted materials. The experiments were carried out in a randomized complete block design with three replications. In the joint analysis of variance, differences were observed among environments and among cultivars, but no consistent cultivar responses to environmental variations were observed. The mean grain yield (5,934 kg.ha -1 ) indicates the region has a high potential for maize, able to compete with such states as Mato Grosso and Goias, traditional producers. All the cultivars tested, except the Sertanejo variety and the BRS 2110 hybrid, showed high stability in the environments. KEY-WORDS: Genotype x environment interaction; cultivar; Zea mays .

Evaluation of phenotypic stability of cassava clones by AMMI analysis in northwestern Paraná state

High yield stability and adaptability of storage root are highly desirable attributes of cassava clones. The objective of this study was therefore to evaluate the effect of the genotype x environment interaction (G x E) and the stability of cassava clones developed at IAC. A subset of eight cassava genotypes was chosen in trials of storage root yield, arranged in a randomized complete block design with four replications, in two counties (Araruna and Maringa), in the northwestern region of Parana State, over five growing seasons (1997-2001). The G x E interaction was evaluated by joint variance analysis and stability and adaptability by AMMI analysis. The G x E interaction was significant (P<0.05) for storage root yield. Results indicated AMMI analysis as an efficient tool for the evaluation of phenotypic adaptability and stability of cassava clones and IAC 190 as the most promising clone.

Effect of mass selection on the mean and genetic variance of maize cultivar AL 25

th cycle. Randomized complete blocks were used for evaluating grain yield and ear height. Individual and joint variance analyses considering the two years of experimental duration compared the mean and variance components of both cycles. A slight reduction in additive genetic variance was observed as the selection proceeded for both analyzed traits. The increase in the means of grain yield and ear height with the selection cycles was also little expressive. The mass selection cycles did not promote significant alterations in this cultivar’s mean and variance.

Estimates of genetic parameters and expected genetic gains with selection in robust coffee

The present paper aimed to study the genetic variation of 15 half-sib progenies of robust coffea ( Coffea canephora Pierre). The trial was conducted at the Instituto Agronomico de Campinas (IAC/APTA) in a randomized complete block design with seven replications and one tree-plot. Annual and joint analyses of variance were obtained to estimate the genetic paramet ers for yield, in order to quantify the genetic gain from selection in eight production years. The genotypic variation coefficient s indicated expressive genetic variability for improvement of the yield. On account of the high variation in annual production, it is recommended that selection should be based on the general mean of the years. In low yield years, larger heritability values, coefficients of genetic variation, index of genotypic determination, and genetic gains were estimated.

Interaction between resistance to Septoria tritici and phenological stages in wheat

Studies dedicated to understanding the behavior of pathogens in relation to their hosts are the starting point for any breeding program aimed to develop resistant cultivars. The objective of this study was to analyze the resistance to Septoria tritici Rob in 77 F11 progenies of wheat derived from the three-way cross Tadinia &lt;FONT FACE=Symbol&gt;´&lt;/FONT&gt; (Yecora rojo &lt;FONT FACE=Symbol&gt;´&lt;/FONT&gt; UC554) in the phenological stages of seedling, tillering, and flag leaf/flowering. Three field experiments were conducted where plants were artificially inoculated at one of the above mentioned phenological stages by spraying with a suspension of conidia. A randomized block design with four replications was used in each experiment. Disease evaluations were made by measuring the foliar area covered with chlorotic and necrotic lesions in the seedling and tillering stages and the leaf area covered with pycnidia in the flag leaf/flowering stage, using disease rating scales. Differences (P &lt; 0.0001) were detected among progenies for Damaged Leaf Area (DLA) in all phenological stages. Joint analysis of variance for DLA indicated interaction between progeny and phenological stage (P &lt; 0.0001) for all binary combinations analyzed (seedling-tillering, seedling-flag leaf and tillering-flag leaf) as it also did for the triple combination involving the three phenological stages. It is necessary to evaluate resistance in more than one phenological stage to guarantee the correct selection of resistant genotypes.

Environment effect on grain quality in early common bean cultivars and lines

The objective of the present study was to assess the technological and nutritional quality of seven early common bean cultivars and nine lines. An experiment in completely randomized blocks was carried out in three locations in the wet 2001/2002 growing season. One hundred gram samples were collected from each material at physical maturity to estimate the grain technological and nutritional characteristics and also the weight of 1000 seeds, shape and degree of seed flattening were assessed by the J and H coefficient, respectively. The joint analysis of variance showed significant genotype and environment effect at 1% probability. The genotype x environment interaction was significant at 1% probability for all the characteristics assessed except for the weight of 1000 seeds and the J coefficient. Cooking time showed positive phenotypic and genotypic correlation with percentage of whole grains after cooking, weight of 1000 seeds and seed shape, indicating the possibility of simultaneous selection among these characteristics. However, the total solids in the sauce correlated negatively with these traits that are desirable in the industrial processes of the common bean.

Selection of soybean genotypes resistant to insects adapted to the cerrados

This study aimed to select productive soybean genotypes, adapted to the conditions of the “Cerrado” and with insect resistance. The experimental material involved 170 soybeans lines F 7:2 obtained from partial diallel crosses (4 x 4), that is, four parents with insect resistance and four other parents with high agronomic performance and the other three lines obtained from the plant breeding program of the ESALQ/USP. The F 7 , F 8 and F 9 generations were evaluated in Goiânia-GO, being the last one evaluated during three different sowing periods (October/21/98, November/09/98 and December/11/98). The following characters were evaluated: days to flowering; plant height at flowering; days to maturity; plant height at maturity; period of grain growth; spotted seeds; 100 seeds weight; foliar area sectioned; lodging; agronomic value; and grain yield. The augmented design was used for the F 7 generation while the complete randomized block design for the F 8 and F 9 generations. An analysis of variance was carried out for each generation and one joint analysis of variance was made for the three sowing periods with F 9 generation. Based on grain yield, through the different experiments, they were identified as to which were the most promising lines for the area, having the best combination of characteristics including insect resistance. The following results were obtained from the analysis: a) ten lines from the early cycle, with high yield, were considered favorable for the cultivation in the “cerrado”, showing high resistance to sucker and defoliator insect, and they involve the genitor IAC-100; b) the line 81-9-13 (OCEPAR-04 x IAC-100) had the best agronomic performance, because it was classified above the mean of the check for all characters evaluated in the F 9 generation; c) the second sowing period (11/09/98) was considered the most favorable for the cultivation of soybean in the region; d) the parental IAC-100 (used as the check) showed good characteristics for grain yield and insect resistance. So, evaluation of this parental should occur in the region, in order to recommend it for cultivation.

Determinação da qualidade e do teor de sólidos solúveis nas diferentes partes do fruto da pinheira (Annona squamosa L.)

O objetivo foi avaliar algumas características qualitativas e estimar o teor de sólidos solúveis (TSS) nas porções basal (ligada ao pedúnculo), mediana e apical do fruto da pinheira. Para a estimação desse teor, três pinhas de cada uma de dez árvores, de pomares localizados em Mossoró-RN e Aracati-CE, com idade entre seis e oito anos, foram utilizadas. As árvores foram consideradas repetições (blocos), os frutos foram considerados parcelas e as porções dos frutos, subparcelas. Três frutos de cada árvore foram descascados e divididos em três porções aproximadamente iguais, da base para o ápice. O material foi triturado e filtrado. No suco obtido, foram feitas três leituras em um refratômetro. A média destas três leituras representou o valor de cada subparcela. A análise de variância conjunta indicou efeitos de locais, blocos em locais, porções e da interação locais x frutos x porções. O peso do fruto variou de 226 a 418 g e o rendimento de polpa, de 45 a 54 %. O TSS na porção basal (26,49 %) foi inferior aos teores das porções mediana (28,02 %) e apical (27,53 %), mas não diferiu significativamente daquele da porção apical.

Analysis of Diallel Cross for the Evaluation of Maize Populations Across Environments

Eleven open-pollinated maize (Zea mays L.) populations were crossed in a diallel scheme and evaluated in five locations in the State of Parana: [1] Ponta Grossa, [2] Pato Branco, [3] Palotina, [4] Londrina and [5] Guarapuava. Two commercial hybrids (P 3230 and BR 201) were included as checks in the experiments, thus completing 68 entries (11 parents, 55 hybrids and 2 checks). Plots were represented by single rows 5 m long spaced 0.9m with 25 plants per plot after thinning. The following traits were analyzed: GY- total plot grain yield expressed in kg/ha after adjustment to 14.5% grain moisture; PH- plant height (cm); EH- ear height (cm); and FF- days for female flowering. Plant height and EH were not included in location [2]; FF was not include in locations [2] and [3]. The joint analysis of variance showed significance for all traits, only for the variation among location, entries, variety effects and average heterosis. For yield the total heterosis in mid-parent percentage varied from –0.96% (PMI 8403 x PMI 9304) to 32.4% (PMI 9302 x PMI 9307). Variety effects (v i ) and general combining ability (g i ) effects were in the range of –1483 to 772 kg/ha and from –847 to 448 kg/ha, respectively. Both g i (for yield) and v i (for the other traits) were used to select two populations to be used in a reciprocal recurrent selection program. BR 106 showed the highest estimates for both g i and v i for yield but also showed undesirable traits (tall plants and late flowering). Some outstanding populations for yield potential per se did not show a good performance in crosses. Other populations with outstanding performance in crosses exhibited lower variety effects for yield or high variety effects for the other traits. Some introduced populations who showed shorter plants and earliness should be submitted to selection for yield, adaptation and other agronomic traits before being indicated for crossing. However, they should be recommended as source populations for short architecture and early flowering. An overall analysis led to the decision of choosing the population IAPAR 26 to be used as contrasting parent of BR 106 in a reciprocal recurrent selection program at IAPAR (Londrina, State of Parana).

Gravity Constraints in Infant Motor Development

The effect of gravity in determining if and when during infancy movements eventuate and the rate at which they develop is unknown. In accordance with intersegmental relationships (Hof, 1992), a muscle moment during infancy would have to develop more rapidly than the gravitational moment before movement could occur. In this investigation, the effect of growth through the influence of gravity on the joint moments in the axial region when infants were in a prone or supine posture was examined. A mathematical model that considers the body to be composed of transverse elliptical cylinders, 1 cm deep and of known density, was used in estimating the mass of the 16 segments of the body. The gravitational moments about 3 joints within the axial region (C7-T1, T12-L1, and the hip) were determined by summation, using the radii from the joint transverse axis to the center of mass of the segments. Infants (N = 27) aged between 9 and 36 weeks at the beginning of the study were tested monthly 6 times, and the effect of growth on the gravitational moments was represented by first-order polynomials. Age x Joint analysis of variance (ANOVA) of the mean slopes of the regressions for the gravitational moments revealed significant main effects for age and joint. The means increased monotonically with the number of segments and decreased as infants aged. The mean slopes of the neck and trunk joints were significantly smaller than that of the the hip joint. With increasing age, the gravitational slope was significantly smaller. The changes in the gravitational moments during infancy are seen as likely control parameters effecting phase shifts in motor patterns during development.

ESTRATIFICAÇÃO DE AMBIENTES EM EXPERIMENTOS DE FEIJOEIRO NO ESTADO DE SÃO PAULO

Efetuaram-se análises da variância conjunta em três experimentos de feijoeiro instalados em várias localidades paulistas, em 1990-93, na época da seca (plantio em janeiro--fevereiro) e na de inverno (maio-junho) e, em 1990-92, na das águas (setembro-outubro), objetivando-se quantificar os valores da interação genótipo por ambiente (GA) e identificar os locais onde essa interação se mostrou menos pronunciada ou, ao contrário, mais contrastante. Os experimentos E1, E2 e E3, delineados em blocos ao acaso com cinco repetições, continham 17, 13 e 13 genótipos respectivamente. Os resultados identificaram Pariquera-Açu, Capão Bonito e Itaberá como ambientes contrastantes, ou seja, com interação GA altamente significativa. Em Ribeirão Preto, Votuporanga, Aguaí, Mococa e Riversul, verificou-se a formação de vários grupos de ambientes com interações GA não significativas; sendo assim, esses locais foram considerados os mais homogêneos para análise de produtividade e avaliação de genótipos.