Francisco das Chagas Vidal Neto

Mutantes morfológicos de algodoeiro herbáceo como fonte de resistência ao bicudo

This work aimed to evaluate the effects of three morphological mutants of upland cotton lines (Gossypium hirsutm L. r. latifolium Hutch.), isolated or in combination in the same cotton genotype, as a source of resistance to boll weevil, Anthonomus grandis Boheman, 1843 (Coleoptera, Curculionidae). The experiment was carried out in the field, under natural infestation, with a completely randomized block design arranged in a factorial 2× 3 plus an additional treatment, with four replications. In a multiple choice test, the character mutant frego bract presented the higher reduction on boll weevil oviposition damage (34.71%), in relation to the normal equivalent. The okra leaf reduced the boll weevil damage only when associated with frego bract (40%). The combination of the three mutant characters in the same plant presented the least square percent with oviposition damage (23.13%).

The use of different clustering methods in the evaluation of genetic diversity in upland cotton

A geracao e avaliacao continua de novos genotipos, por meio do melhoramento genetico, e fundamental para a obtencao de novas cultivares. Foi o objetivo deste trabalho avaliar a divergencia genetica entre cultivares de algodoeiro herbaceo (Gossypium hirsutum L.), por meio de caracteristicas agronomicas e tecnologicas da fibra, visando a selecao de parentais superiores. O experimento foi implantado na Universidade Federal do Ceara, Fortaleza/CE, em 2010. Foram usadas 11 cultivares de algodao herbaceo, utilizando o delineamento experimental em blocos casualizados, com tres repeticoes. Para avaliacao da divergencia genetica entre as cultivares foi obtida a matriz de distâncias generalizada de Mahalanobis, e em seguida, realizado agrupamento por diferentes metodos, sendo eles o metodo da ligacao simples, de Ward, da ligacao completa, da mediana, da ligacao media dentro de grupo e da ligacao media entre grupo. Ha variabilidade genetica entre os genotipos avaliados. O metodo de agrupamento que apresentou maior consistencia foi a ligacao media entre grupo. O peso medio do capulho apresentou a maior contribuicao para a diversidade genetica, seguida do alongamento a ruptura dentre os caracteres avaliados. As cultivares de maior divergencia genetica, usando o metodo de ligacao media entre grupo, foram a BRS Acacia e LD Frego; as de maior similaridade foram a BRS Itauba e BRS Araripe.

Correlations and path analysis in components of fiber yield in cultivars of upland cotton

This study evaluated the relative contribution of agronomic and technological components on the fiber yield in upland cotton cultivars. The experiment was carried out with 11 upland cotton cultivars in a completely randomized blocks design with three replications. Initially, we performed analysis of variance, with the F test at 5% probability for the effect of cultivar as fixed ef - fects as well as block and environment effects as random. Then the values were ordered according to cluster test Scott-Knott, at 5% probability level. The significance of the null hypothesis that all possible canonical correlations are null was evaluated using the chi-square test. The correlations were estimated through the path analysis. By examining the canonical correla- tions there was dependence between the two groups of variables and therefore it is possible to promote changes in certain characteristics through the selection of others correlated. Plants of upland cotton with higher fiber yield were influenced by the decrease in average weight of the cotton boll. When there is a reduced fiber yield, there is also an increase in uniformity and strength thereof. The fiber resistance had negative indirect effects on the fiber uniformity and length.

Preferência de Bemisia tabaci biótipo B em linhagens mutantes de algodoeiro

The effects of cotton lines (Gossypium hirsutum L. r. latifolium Hutch.) with mutants morphologic characteristics: okra leaf, frego bract and red plant in relation to host plant resistance to whitefly (Bemisia tabaci bioyipe B Hemiptera: Aleyrodidae), were evaluated in choice or no choice assays. The assays were carried out in the greenhouse conditions, according to a completely randomized block design, in a 23 + 1 in a factorial arrangement with four replications. The mutant with red plant characteristic was less attractive and less preferred for oviposition than the normal green plant does, in both, whit or without choice tests. It did not have preference in relation to the form of the leaf and bract type.

Desempenho de híbridos de cajueiro-anão-precoce no litoral do estado do Ceará

The selection of cashew genotypes in segregating progenies obtained via artificial hybridization consists of a chance to associate favorable genes inherited from known parents. Additionally, knowing the dynamics of the main characters of interest can help define effective strategies to obtain genetic gains. So, the objective of this study was to evaluate the performance of cashew full-sib progenies in relation to production and morphological characters, cultivated in the municipality of Pacajus-CE in three growing seasons, and to estimate the correlations among traits of interest. In the seasons of 2010, 2011 and 2012 were evaluated seven progenies of cashew in relation to morphological and productive characters. The crosses CCP 76 x BRS 226, CCP 76 x Embrapa 51 and BRS 226 x Embrapa 51 shown to be promising in generating superior genotypes for agronomic interest characters. The size of the plant showed positive associations with productivity of nuts, and the number of nuts per plant showed strong correlation with yield. So, it is important to emphasize the necessity to perform the selection seeking balance in relation to the performance on morphological and productive characters in order to obtain genotypes that combine high productivity of nuts and appropriate size of plant.