Genetic analysis of resistance to root-lesion nematode (Pratylenchus thornei) in wheat

The inheritance of resistance to root-lesion nematode was investigated in five synthetic hexaploid wheat lines and two bread wheat lines using a half-diallel design of F-1 and F-2 crosses. The combining ability of resistance genes in the synthetic hexaploid wheat lines was compared with the performance of the bread wheat line 'GS50a', the source of resistance to Pratylenchus thornei used in Australian wheat breeding programmes. Replicated glasshouse trials identified P. thornei resistance as polygenic and additive in gene action. General combining ability (GCA) of the parents was more important than specific combining ability (SCA) effects in the inheritance of P. thornei resistance in both F-1 and F-2 populations. The synthetic hexaploid wheat line 'CPI133872' was identified as the best general combiner, however, all five synthetic hexaploid wheat lines possessed better GCA than 'GS50a'. The synthetic hexaploid wheat lines contain novel sources of P. thornei resistance that will provide alternative and more effective sources of resistance to be utilized in wheat breeding programmes.

Potential to increase yield in lucerne (Medicago sativa subsp sativa) through introgression of Medicago sativa subsp falcata into Australian adapted material

The effect of interspecific heterosis in crosses between Medicago sativa subsp. sativa and M. sativa subsp. falcata was assessed. Three sativa and 3 falcata plants were crossed in a diallel design. Progeny dry matter yield and natural plant height were assessed in a replicated field experiment at Gatton, Queensland. Yield data were analysed using the method of residual maximum likelihood (REML) and Griffing's model 1. There were significant differences between the reciprocal, general combining ability (GCA), and specific combining ability (SCA) effects. As expected, S-1 populations were lower yielding than their respective intraspecific cross and falcata x falcata crosses were significantly lower yielding than sativa x sativa crosses. Some of the interspecific crosses indicated substantial SCA effects, yielding at least as well as the best sativa x sativa crosses. We have demonstrated the potential usefulness of unselected M. sativa subsp. falcata as a heterotic group in the improvement of yield in northern Australian adapted lucerne material, and discuss how it could be incorporated into future breeding to overcome the yield stagnation currently being experienced in Australian programs.

Diallel analysis for frogeye leaf spot resistance in soybean

Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paran�� and Uberaba), with different levels of resistance to Cercospora sojina, were crossed in a diallel design to determine the general (GCA) and specific (SCA) combining abilities relative to the inheritance of the resistance. Race 04 of the fungus was inoculated in the parents and in the 21 F1 hybrids in a greenhouse in a completely randomized design, with 12 replications. The reactions to the disease were evaluated 20 days after the inoculation, always on the most infected leaflet. Both GCA and SCA were significant for all the evaluated characters, being inferred that, for the expression of the characters, the additive, dominant and, possibly, epistatic genic actions were important. The largest values of estimated SCA effect (<IMG SRC="/img/revistas/pab/v38n6/18215x01.gif">ij) were observed in the hybrid combinations where at least one parent presented high GCA. Cristalina, Davis and Uberaba cultivars showed the largest estimates for GCA effect (<IMG SRC="/img/revistas/pab/v38n6/18215x02.gif">i), and from the analysis of <IMG SRC="/img/revistas/pab/v38n6/18215x03.gif">ii, the contribution of these parents to heterosis of their hybrids will be towards the reduction of the disease symptoms. Therefore, these cultivars are indicated as parents in breeding programs that seek the development of soybean cultivars with resistance to frogeye leaf spot.

Morphological, pedigree, and molecular distances and their association with hybrid wheat performance

The objectives of this work were to estimate the genetic distance among wheat genotypes using morphological, pedigree, molecular, and combined morphological and molecular measures, to determine the correlations between these measures, and to evaluate the combining ability of the genotypes. Three generations and two planting designs were studied. Six wheat genotypes were crossed using a diallel design. The F1, F2 and F3generations were evaluated in the field, in the crop seasons of 2003, 2004 and 2005, under spaced plant and full-row planting designs. The estimated general and specific combining abilities of tested hybrids were influenced both by the generation and the planting design. The correlation coefficients among the distance measures and between these measures and genotype performances of different generations for the two planting designs were low to moderate. In order to obtain a more precise estimate of the genetic distance among cultivars and its association with the hybrid performance, more than one generation, planting design, and genetic distance estimation technique should be employed.

Avalia����o de sete fam��lias S2 prol��ficas de minimilho para a produ����o de h��bridos

Sete fam��lias S2 de minimilho foram cruzadas entre si em esquema dial��lico completo. Os h��bridos simples obtidos foram avaliados na Esta����o Experimental de S��o Manuel, da Faculdade de Ci��ncias Agr��rias da Universidade de S��o Paulo (UNESP-Botucatu). O experimento foi delineado em blocos casualizados com tr��s repeti����es. As parcelas consistiram de fileiras de 5 m espa��adas entre si por 0,90 m, com 50 plantas cada uma. Avaliaram-se as seguintes caracter��sticas: n��mero de espigas por parcela (NE), massa de espigas com palha (MECP) e sem palha (MESP), comprimento de espigas com palha (CECP) e sem palha (CESP), di��metro de espigas com palha (DECP) e sem palha (DESP), altura da planta (AP) e da espiga (AE). Estimaram-se os efeitos da capacidade geral e espec��fica de combina����o das fam��lias pelo m��todo 4, modelo estat��stico 1, proposto por Griffing. Houve predomin��ncia dos efeitos g��nicos aditivos para a massa de espigas com palha e sem palha. Entretanto, para o comprimento de espigas sem palha, di��metro de espigas com palha e sem palha, altura de planta e altura de espigas, os efeitos g��nicos aditivos e n��o aditivos foram equivalentes. Pelas estimativas das capacidades combinat��rias para o n��mero de espigas por parcela, massa de espigas com palha e sem palha, a fam��lia 27 �� a indicada para obter gen��tipos superiores.

Capacidade de combina����o em sete popula����es de melancia

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Dialelo entre linhagens de uma popula����o de pepino do tipo 'Caipira'

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Capacidade combinat��ria e heterose de linhagens de pepino do grupo japon��s para caracteres de produ����o

O objetivo do trabalho foi estimar o efeito da capacidade geral (CGC) e espec��fica (CEC) de combina����o e a heterose de linhagens e popula����es de pepino japon��s, empregando-se um topcross. Foram obtidos 16 h��bridos experimentais a partir de duas popula����es testadoras (gera����o F2 de Yoshinari, T Y, e de Natsusuzumi, T N) e oito linhagens S5 obtidas a partir do h��brido comercial Hokuho. Tamb��m foi avaliado o h��brido F1 Hokuho, totalizando 27 tratamentos. O delineamento experimental utilizado foi em blocos casualizados, com quatro repeti����es e cada parcela foi constitu��da de quatro plantas. Foram avaliadas as massas totais e comerciais, n��mero de frutos total e comercial, porcentagem de frutos comerciais e massa m��dia de frutos comerciais. A popula����o de Yoshinari (T Y) apresentou, em m��dia, melhor capacidade de se combinar com as linhagens de Hokuho. A linhagem L7 apresentou os maiores valores positivos da estimativa da CGC para a maioria das caracter��sticas avaliadas. Os h��bridos H1Y e H1N, que apresentavam a linhagem L1 como parental, foram os que apresentaram maiores valores para a estimativa da CEC com as popula����es testadoras para a maioria das caracter��sticas avaliadas, enquanto os que tinham a linhagem L5 como parental (H5Y e H5N) apresentaram os menores valores. A popula����o F2 proveniente do h��brido Yoshinari apresentou, em geral, maior potencial de originar linhagens superiores para cruzamentos com linhagens de Hokuho, a fim de se obter h��bridos com maior potencial produtivo. A heterose foi positiva para a grande maioria das caracter��sticas avaliadas.

Diallel analysis of maize resistance to Phaeosphaeria maydis

Em programas de melhoramento visando resist��ncia gen��tica a doen��as, a estimativa de par��metros gen��ticos que governam a resist��ncia permite direcionar a introdu����o de resist��ncia em germoplasmas. O objetivo deste trabalho foi estimar os efeitos heter��ticos, a capacidade geral (CGC) e espec��fica (CEC) de combina����o, utilizando-se de dois m��todos de avalia����o da resist��ncia, �� Phaeosphaeria maydis atrav��s da an��lise dial��lica de 36 h��bridos F1 e de suas nove linhagens genitoras, em experimentos conduzidos em tr��s ambientes. Foi utilizado um delineamento experimental em blocos casualizados com tr��s repeti����es e a parcela experimental foi representada por uma fileira de 5 m. As diferen��as entre as estimativas da capacidade de combina����o, em diferentes ambientes e para os dois m��todos de avalia����o, apresentaram efeitos significativos (P < 0.01) para ambientes (E), CGC e CGC x E. O efeito de CEC e a intera����o CEC x E n��o foi significativa para os dois m��todos de avalia����o. Os efeitos de CGC foram mais importantes que CEC nesse conjunto de linhagens, sugerindo que efeitos gen��ticos aditivos s��o mais importantes como fonte de varia����o para resist��ncia a esta doen��a. Efeitos heter��ticos para resist��ncia foram estimados, sendo poss��vel identificar combina����es h��bridas espec��ficas entre linhagens com alto potencial para o controle gen��tico deste pat��geno. Resultados para os dois m��todos de avalia����o foram praticamente id��nticos, embora o m��todo PI seja de maior praticidade de uso.

Capacidade combinat��ria para frutifica����o em cultivares de nogueira macad��mia

A 5 �� 5 diallel experiment was conducted at Experimental Station of Tiet��, SP, aiming to evaluate the combining ability amongst macadamia nut trees (Macadamia integrifolia Maiden & Betche) cultivars IAC Campinas A, IAC 2-23 A, IAC 4-12 B, IAC 4-20 e IAC 5-10. The initial fruit set was evaluated 14 days after manual pollination and showed that every cultivar presented self incompatibility. There were significant general and specific combining ability amongst cultivars and reciprocal effects. The cultivar IAC Campinas A reduced the initial fruit set at all crossing in which was used as female progenitor. The best results for initial fruit set were showed by crossings between following cultivars: IAC 4-20 �� IAC Campinas A, IAC 4-12 B �� IAC 2-23 A, IAC 4-20 x�� IAC 4-12 B, IAC 5-10 �� IAC 2-23 A, IAC 5-10 �� IAC 4-20, IAC 4-20 �� IAC 2-23 A e IAC 5-10 �� IAC 4-12 B.

Capacidade de combina����o de linhagens de pepino (Cucumis sativus L.) do grupo japon��s

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Capacidade de combina����o para sele����o de gen��tipos de milho

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

High-level and phonological awareness abilities of children following management for supratentorial tumour: Part II

Background. Limited information is available regarding the impact of childhood tumour on the cerebral hemispheres and supratentorial cranial fossa. However, a recent study found that children managed for a tumour located in this region may demonstrate reduced general language abilities. However, the indirect or direct impact of a tumour in this region on higher-level language abilities in childhood is at present largely unknown. Materials and methods. The present study examined the higher language and phonological awareness abilities of five children treated for supratentorial tumour ranging in age from seven to fourteen years in age. Assessments included measures of receptive and expressive semantic abilities, inferencing, figurative language, and problem solving, as well as a comprehensive pre-literacy test. Results. As a group, reductions were evident in problem solving, and in the ability to receive and decode content of high-level language when compared to a group of age- and gender-matched peers. At an individual level, only two of five children managed for supratentorial tumour demonstrated language deficits. These two cases were noted to be the same children previously identified as also having general language deficits. More widespread findings were noted in phonological awareness, with four of the five children previously managed for supratentorial tumour demonstrating weaknesses in one or more areas. Conclusions. Findings demonstrated that weaknesses in general language ability in children managed for supratentorial tumour may indicate higher-level language difficulties. Language abilities beyond general measures of language should be monitored, as well as long-term consideration of phonological awareness abilities in this population.

Benef��cios de uma interven����o espec��fica em desenvolvimento da linguagem, em crian��as diagnosticadas com ���espectro do autismo���

Disserta����o Apresentada �� Escola Superior de Educa����o de Lisboa para obten����o de grau de mestre em Ci��ncias da Educa����o - Especialidade em Interven����o Precoce

Incremental Validity and Indirect effect of Ethical Development on Work Performance

We modeled work performance as outcomes of individual-differences mediated by technical performance. Beyond the "usual suspects" (e.g., general mental ability, and personality), we also measured the ethical development of participants (n = 460). We surmised that ethical development - which has not been extensively studied as a predictor of work performance while controlling for established predictors - captures unique variance in both technical and work performance. Results demonstrated incremental validity for ethical development in predicting technical performance, which in turn predicted work performance. The indirect effect of ethical development was significant too. Our results highlight the importance of process models of performance, which include proximal as well as distal individual differences.