Luiz Antônio dos Santos Dias

Estabilidade de cultivares e linhagens de feijoeiro em diferentes ambientes no estado de São Paulo

The present study had the objective of a genotypic evaluation of common bean lines in the state of Sao Paulo. Genotypic values of the lines for each location and for the environment mean of all locations were predicted as well. Studies on the adaptability and stability of the predicted genotypic values were realized by the BLUP procedure. The cultivar Grauna and line GEN 96A31 presented an average superiority of 10% over the general mean of the 15 environments. These values were computed including the penalization of the lines for the instability across locations and simultaneously crediting the response capacity (adaptability) to improved environments, using intrinsic properties of the MHPRVG method (Harmonic mean of the relative performance of the genetic values). The methods MHPRVG, Lin & Binns and Annicchiarico selected the same lines. Moreover, the results provided by the method MHPRVG were in the same measurement scale of the evaluated trait and were directly interpreted as genetic values simultaneously, for yield, stability and adaptability.

Antiquity, botany, origin and domestication of Jatropha curcas (Euphorbiaceae), a plant species with potential for biodiesel production.

Jatropha curcas is a multi-purpose plant species, with many advantages for biodiesel production. Its potential oil productivity is 1.9 t/ha, beginning the fourth year after planting. Nevertheless, limitations such as high harvest cost, lack of scientific konowledge and low profitability have prevented it from being utilized commercially. In order to provide information that could be useful to improve the status of this species as a bioenergy plant, we elucidated the center of origin and the center of domestication of J. curcas (Mexico). Evidence of the antiquity of knowledge of J. curcas by Olmeca people, who lived 3500-5000 years ago, reinforces its Mexican origin. The existence of non-toxic types, which only exist in that country, along with DNA studies, also strongly suggest that Mexico is the domestication center of this species. In Brazil, the Northern region of Minas Gerais State presents types with the highest oil content. Here we propose this region as a secondary center of diversity of J. curcas.

Componentes primários e secundários do rendimento de óleo de pinhão-manso

The definition of the most suitable plant selection criteria is especially important for Jatropha curcas L. as subsidies the genetic progress estimates and the ideotype characterization, described in terms of the traits that are thought to enhance genetic yield potential. The objective of this study was to estimate the direct and indirect effects of seven vegetative traits and four seed quality traits on J. curcas oil yield. The traits grain yield and the weight of the nuts showed direct and positive effect on the oil yield. The tree volume showed the major indirect and positive effect on the main variable through grain yield. The development of J. curcas with higher oil yield in the evaluated population has to consider the selection of plants with higher yield and tree volume, maintaining the variability of the grain quality traits.

Avaliação do vigor de sementes de melancia (Citrullus lunatus Schrad.) pelo teste de envelhecimento acelerado

The objective of this study was to determine the efficacy of the accelerated aging test for vigor evaluation in watermelon seeds. Four seed lots from the Crimson Sweet cultivar were submitted to accelerated aging at 41 and 45°C for 48, 72 and 96 hours, at 100 and 76% relative humidity. The results were related with standard germination, first count, cool germination and seedling emergence in soil. It was concluded that the traditional methodology of the accelerated aging test (100% RH) was shown to be more efficient than the alternative method (76% RH) for vigor evaluation of watermelon seeds. Accelerated aging at 41°C and 100% RH for 48 hours was the most consistent procedure to indicate seed vigor levels.

Adaptabilidade e estabilidade de produção de cultivares e linhagens de feijoeiro no Estado de São Paulo

Twelve common beans cultivars and lines were evaluated in Sao Paulo State, Brazil according to 24 environments (growing season, years and locations). The yield stability and adaptability were determined by two methods of analysis and their efficiency evaluated. IAC-Carioca and IAC-Una cultivars were used as standards for grain types carioca and black, respectively. For each environment the experiment was set up in randomized complete block design with four replications, each of them consisting of two central lines of five long flanked by two border lines. Stability and adaptability were estimated using two methods, Cruz and colleagues, modified by Carneiro. The results indicated that Ruda, Gen12, IAC-Carioca Ete and FT-Bonito cultivars are recommended for planting in several environments, due to their wide adaptability. Considering the adaptability to specific environment, the more stable cultivars were FT-Nobre, FT-Bonito and Ruda (rainy growing season); Ruda, IAC-Carioca Ete and Gen12 (dry season); and Perola, FT-Bonito and Gen12 (winter season). The two methods of stability and adaptability evaluated were in disagreement. The Lin and Binns method identified the most stable, responsive and highest yielding cultivars. This method is efficient, simple and has unique parameters that can be easily interpreted. Therefore, it is suggested that the selection and recommendation of cultivars for wide or specific adaptation, be based on results indicated by Lin and Binns method.

Genetic improvement of sugar cane for bioenergy: the brazilian experience in network research with RIDESA

In this paper, it is presented RIDESAs model for sugar cane breeding to ethanol, and its scientific, technological and human resources training contributions. RIDESA is an inter-university network for the development of sugar cane industry in Brazil, and was formed by a technical cooperation agreement between ten public universities. The model of network management is presented in this study, which involves, among other things, the public-private partnership (Universities-Mills) for the development of cultivars. RIDESA has produced 59 cultivars since 1990 and is now responsible for 59% of the total area cultivated with this plant in Brazil. In the last five years, 286 agronomists were trained in breeding programs at universities that comprise RIDESA. In this same period, the network formed 35 professors, 24 doctors and 7 post-docs in researches with this crop. It is also presented a conceptual approach on methods of sugar cane breeding involving families and genome-wide selection.

Genetic distance and its association with heterosis in cacao

The efficiency of cacao breeding program can be increased by choosing superior crosses to be made between divergent clones. We assessed the genetic distance among five clones with RAPD data (genetic distance - GD) and with yield component data (Mahalanobis distance - MD). The clones were evaluated in a diallel, during five years, for five yield components. A total of 130 RAPD bands were scored. GD and MD were used to determine the correlation between genetic distances among clones and the performance of their hybrids. The correlation between GD and MD was 0.67 (P=0.03). Both distances were related to heterotic performance of hybrids for wet seed weight/plant and wet seed weight/fruit. The average hybrid performance for the same two yield components was correlated with only MD. Hence, genetic distances measured by RAPD and yield components can be used as a guide to the choice of the superior crosses.

Genetic divergence between populations of the stingless bee uruçu amarela (Melipona rufiventris group, Hymenoptera, Meliponini): is there a new Melipona species in the Brazilian state of Minas Gerais?

Allozyme, microsatellite and random amplified polymorphic DNA (RAPD) molecular markers were used to investigate the within and between population genetic variability and between population genetic differentiation of the Brazilian stingless bee urucu amarela (nominally Melipona rufiventris Lepeletier, 1836) present in savanna and Atlantic forest habitats of the Brazilian state of Minas Gerais (MG). We found low levels of within population variability, although there were a large number of private alleles that specifically characterized these populations. The FST values indicated a high level of genetic diversity between populations. Analysis of molecular variance (AMOVA) showed a high degree of population differentiation between the savanna and Atlantic forest habitats, confirmed by population pairwise FST data. Principal coordinates analysis and unweighted pair-group method using an arithmetic average (UPGMA) dendrograms also confirmed that in Minas Gerais the savanna populations (M. rufiventris) were genetically distinct from those present in the Atlantic forest (M. mondury). In addition, populations from locations near the towns of Dom Bosco and Brasilândia de Minas were genetically different from those collected in other localities in the savanna. Our data indicate that populations of urucu amarela found in the savanna and Atlantic forest habitats of Minas Gerais state should be treated separately for conservation purposes and that special attention should be given to the populations found in the region of Dom Bosco and Brasilândia de Minas until their taxonomic status is clarified.

Tratamentos para superação da dormência em sementes de mamão

The objective of this study was to define appropriate treatments to overcome dormancy in papaya seeds. Seeds with and without sarcotesta extracted from papaya fruits of the Formosa group, hybrid Tainung 01, were used. The following treatments to overcome dormancy were applied on seeds without sarcotesta: leaching for 2 and 4h, drying at 40oC/96h, pre-chilling at 10oC/14 days, accerelated aging at 41oC for 36, 48 e 72h, soaking in NaOCl 0,5% for 1, 2, 3, 4 and 5h, soaking in KNO3 1M for 30, 60, 90 and 120 min., soaking in GA3 400, 600 and 800 ppm for 24h, substratum moistened with GA3 400, 600 and 800 ppm, storage for 3, 6 and 9 months and heat-shock at 15-35o C. After each treatment, germination at 15 and 30 days was evaluated. Seeds with sarcotesta had lower germination speed and percentage. The best treatments to overcome dormancy in papaya seeds were the use of substratum moistened with GA3 600 ppm or the immersion of the seeds GA3 600 ppm for 24 hours and immersion of the seeds in KNO3 1M for 30, 60 and 90 minutes. Seed dormancy was broken after storage for 3 and 6 months.

Uso do teste de tetrazólio para avaliação da qualidade fisiológica de sementes de abobrinha

165RESUMO – O trabalho teve como objetivo desenvolver metodologia apropriada para o uso doteste de tetrazolio em sementes de abobrinha, visando determinar a viabilidade e o vigor. Osseguintes procedimentos foram avaliados: umedecimento das sementes em papel toalha por 16 e24h, a 25°C; imersao direta em agua, em câmara BOD, a 40°C, por 15, 30 e 60 minutos para a remocaodo tegumento e por mais 30 e 60 minutos para retirada da membrana que envolve o embriao. Osembrioes foram entao imersos em solucao de tetrazolio a 0,05 e 0,075% por 30, 60 e 90 minutos, emcâmara BOD, a 40°C, para coloracao. Paralelamente, foram conduzidos testes de germinacao evigor, estabelecendo-se cinco classes de viabilidade e vigor. A metodologia desenvolvida foiaplicada a oito lotes, sendo aferida com os resultados dos testes de germinacao, envelhecimentoacelerado e emergencia de plântulas em areia. O teste de tetrazolio mostrou-se eficiente para avaliara viabilidade e o vigor das sementes de abobrinha. O metodo de pre-condicionamento mais eficientefoi imersao direta em agua, a 40°C, por 30 minutos para a remocao do tegumento e por mais 30minutos para a retirada da membrana interna. A coloracao ideal dos embrioes foi obtida apos 60minutos de imersao em solucao de tetrazolio a 0,05 ou 0,075% a 40°C.Termos para indexacao: