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Search Results: 1 - 10 of 11090 matches for " plant breeding "
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Biodiversity in a Tomato Germplasm for Free Amino Acid and Pigment Content of Ripening Fruits  [PDF]
Guillermo Raúl Pratta, Gustavo Rubén Rodríguez, Roxana Zorzoli, Liliana Amelia Picardi, Estela Marta Valle
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.22027
Abstract: Free amino acid and pigment composition in fruits at two ripening stages from a selected tomato germplasm was stu-died. The aims were contributing to knowledge on variability of ripening metabolism and identifying more consis-tently the genetic background of the plant material under analysis. Significant differences (p < 0.05) were found among ripening stages and among genotypes within ripening stage for all amino acids and pigments except by asparagine, alanine and chlorophyll b contents. The highest relative amino acid content corresponded to glutamate, glutamine, and GABA though some genotypes had relatively high asparagine content. Glutamate, glutamine and GABA performed oppositely: the former increased along ripening while the latter two decreased in their relative content. A Principal Components (PC) analysis was applied, determining that metabolites having the greatest contribution to general variability were threonine, serine, glutamate, glutamine, glycine, isoleucine, leucine, tyrosine, phenylalanine, lycopene and beta- carotene, which showed the highest association with PC1. Alanine and chlorophylls a and b were highly associated to PC2. These two first PC explained the 62% of the total variation, and genotypes were distributed according to the ripening stage in their coordinates. Accordingly, a Hierarchical Clustering resulted in a dendrogram having a relatively high cophenetic correlation (0.70), in which two well defined groups were obtained according to ripening stage. These results verified the existence of variability in the metabolism of ripening fruit for amino acids and pigments, and allowed to identify unequivocally a set of selected tomato germplasm according to the fruit metabolic profiles in these two ripening stages.
Conserva??o e germina??o in vitro de pólen de milho (Zea mays subsp. mays)
Almeida, Cícero;Amaral, Adriane leite do;Barbosa Neto, José fernandes;Sereno, Maria Jane Cruz de Melo;
Brazilian Journal of Botany , 2011, DOI: 10.1590/S0100-84042011000400003
Abstract: the storage of pollen can be considered an important tool for maize breeding programs, allowing to preserve, under artificial conditions, the viability of male gametes and extend the possibilities of crossings regardless of flowering time of parental varieties. this study aimed to evaluate the culture media for in vitro germination of corn pollen and analyze storage conditions. to examine viability, six different culture media containing sucrose, boric acid, calcium chloride and agar were evaluated. for pollen preservation, two temperatures (4 oc and -20 oc) and two agents of pollen dehydration (silica gel and hydrated calcium chloride) were evaluated. the high values of pollen viability up to 30 days of storage indicate that dehydration in silica gel and storage at 4 oc preserve the viability of corn pollen. the culture medium that provided the highest germination rate in vitro was the composition of 0.7% agar, 17% sucrose, 0.01% boric acid and 0.03% calcium chloride hydrate.
Contribution of graduate programs in plant breeding to the education of plant breeders in Brazil
Isaias Olívio Geraldi
Crop Breeding and Applied Biotechnology , 2012,
Abstract: The success of agribusiness in Brazil in recent decades is unquestionable. Although the country has always had favorable conditions for agriculture (land, water and climate), this success has only come about recently, due to scientific research, which has resulted in considerable increases in yield and in improvement of product quality, as well as making the occupation of new agricultural frontiers possible. A decisive factor for development of agriculture in the country was the creation of EMBRAPA in 1973, which, in a few years, led to considerable demand for researchers with training in graduate programs. Among them are plant breeders, who came to exercise their activity throughout the country and in all ecosystems. The training of plant breeders was only possible because, as from the middle of the 1960s, the country began a wide-ranging education program, with the creation of several graduate programs in genetics and plant breeding.
Análise biométrica de ganhos por sele??o em popula??o de milho pipoca de quinto ciclo de sele??o recorrente
Rangel, Ramon Macedo;Amaral Júnior, Antonio Teixeira do;Gon?alves, Leandro Sim?es Azeredo;Freitas Júnior, Silvério de Paiva;Candido, Liliam Silvia;
Revista Ciência Agron?mica , 2011, DOI: 10.1590/S1806-66902011000200029
Abstract: aiming to select superior progenies for concentration of favorable alleles in a popcorn population on the fifth cycle of intrapopulation full-sib recurrent selection, two hundred progenies were evaluated for six agronomic traits, including grain yield and popping expansion, in randomized complete block design with two replications within sets, in two distinct environments: colégio estadual agrícola ant?nio sarlo, in campos dos goytacazes, and experimental station of pesagro-rio, located in itaocara, rio de janeiro state, in 2007/2008. there were significant differences among families within sets in all traits, indicating the presence of genetic variability to be exploited in the future cycles. the utilized selection indexes were the mulamba and mock; and smith and hazel. the mulamba and mock index propitiated more elevated magnitudes of the predicted gains for most of the traits, including popping expansion and grain yield, with values of 6.01 and 8.53%, respectively, utilizing arbitrary weight attributed by tentative.
Classifica??o multivariada de curvas de progresso da requeima do tomateiro entre acessos do banco de germaplasma de hortali?as da UFV
Azevedo, Camila Ferreira;Silva, Fabyano Fonseca e;Ribeiro, Natália Barbosa;Silva, Derly Jose Henriques da;Cecon, Paulo Roberto;Barili, Leiri Daiane;Pinheiro, Valeria Rosado;
Ciência Rural , 2012, DOI: 10.1590/S0103-84782012000300005
Abstract: the objective of this paper was to present a methodology for the analysis of experiments in plant pathology that considers the comparison of disease progress curves in the presence of a large number of treatments by cluster analysis. forty-two accessions were grown from the germoplasma vegetable bank (bgh), of universidade federal de vi?osa (ufv). the exponential model was fitted to the data of late blight severity percentage, and the obtained parameter estimates obtained on the initial incidence of the disease (yo) and rate of disease progression (r) - were submitted to the multivariate analysis of variance (manova). the adjusted means were submitted to the cluster analysis. an optimal number of six distinct groups was observed.
Impacto del fitomejoramiento participativo como parte de la innovación agropecuaria local por difusión de diversidad genética en sectores agrícolas de Pinar del Río
Márquez,M; Valdés,N; Pérez,D; Ortiz,R;
Cultivos Tropicales , 2009,
Abstract: a survey of species and varieties was performed in 17 farms from la palma municipality, over the areas involved by participatory plant breeding (ppb) project. the study was aimed at analyzing how much the municipal agriculture ecosystem has been improved by introducing diversity. margalef′s specific diversity and shannon-weiner’s specific richness indexes were calculated, besides considering three stages: previous to ppb, after ppb, and when implementing the local agricultural innovation program (pial). results showed that diversity has increased with time, mainly regarding grain, garden and vegetable groups; farmers adopt diversity according to their own interests, ecosystems are still ready for adopting new species and varieties, also the diversity introduced has led to ecosystem stability.
Pesquisa Agropecuária Brasileira , 1999, DOI: 10.1590/S0100-204X1999001100003
Abstract: this paper focused on four alternatives of experiment group analysis in square lattice as far as the estimation of variance components and some genetic parameters are concerned: 1) intra-block analysis with adjusted treatment and blocks within unadjusted repetitions; 2) lattice analysis as complete randomized blocks; 3) intrablock analysis with unadjusted treatment and blocks within adjusted repetitions; 4) lattice analysis as complete randomized blocks, by utilizing the adjusted means of treatments, obtained from the analysis with recovery of interblock information, having as mean square of the error the mean of the errors (mean effective variance) of the individual analyses, of this same analysis with recovery of interblock information. for the four alternatives of analysis, the estimators and estimates were obtained for the variance components and heritability coefficients. the classification of material was also studied. the present study suggests that for each experiment and depending on the objectives of the analysis, one should observe which alternative of analysis is preferable, mainly in cases where a negative estimate is obtained for the variance component due to effects of blocks within adjusted repetitions in the individual analyses.
Introdu??o e avalia??o de clones de goiabeira de polpa branca (Psidium guajava L.) na regi?o do Submédio S?o Francisco
Revista Brasileira de Fruticultura , 2002, DOI: 10.1590/S0100-29452002000100026
Abstract: with the objective of evaluating the genetic variability and selecting crop alternatives for "in natura" market of white flesh guava, 22 varieties from the ipa germplasm were introduced and evaluated in the submédio s?o francisco river valley. the plants were propagated through grafting, using four plants per variety in a 6.0m x 6.0m spacing. the following parameters were evaluated from 1993 to 1998: plant production (kg), number of fruits harvested per cycle and mean fruit weight (g). among these parameters, mainly mean fruit weight (one of the most important parameters for table guava), the varieties banaras and luck now showed the best performance for commercial purposes, with, respectively, 98.07 kg/plant, 813 fruits/cycle, mean fruit weight of 176 g, and 118.22 kg/plant, 940 fruits/cycle and mean fruit weight of 131.39 g. the variety banaras had 11.1obrix and tss/acidity ratio of 2.8 and luck now had 12.1o brix and tss/acidity ratio of 3.0.
Physical purity and germination of sugarcane seeds (caryopses) (Saccharum spp.)
Caieiro, Juliana Terezinha;Panobianco, Maristela;Bespalhok Filho, Jo?o Carlos;Ohlson, Osvaldo de Castro;
Revista Brasileira de Sementes , 2010, DOI: 10.1590/S0101-31222010000200017
Abstract: plant breeding is generally done through sexual reproduction even when the species is propagated asexually for commercial exploitation, as for example, in sugarcane. therefore, the development of procedures to evaluate sugarcane seed viability is important for plant breeding programs. the objective of this research was to develop a methodology for analyzing the viability of sugarcane seeds (saccharum spp.). three crosses were used, two biparental crosses and one polycross. for the germination test study, two substrates (paper and sand) and three constant incubation temperatures (25 oc, 30 oc and 35 oc), in the presence of constant light and also an alternating temperatures (20-30 oc), with 8 hours light (30 oc) and 16 hours darkness (20 oc), were studied. seedlings were evaluated every five days. the results demonstrated that temperature affected sugarcane seed germination with the most favorable conditions being the alternating temperature (20-30 oc) and the constant temperature of 30 oc on a paper substrate.
Relationship between seed technology research and federal plant breeding programs
Krzyzanowski, F. C.;
Scientia Agricola , 1998, DOI: 10.1590/S0103-90161998000500015
Abstract: this paper deals with the contributions seed technology can provide for soybean breeding programs for seed quality. efforts can be placed on seed quality assurance (diacom) to assist the production system, from genetic up to certified seed in releasing a product of high quality. another approach is the development of screening methods, based on seed technology tests (vigor tests), for selecting genotypes according to different traits relating to seed quality. an understanding of seed quality mechanisms, such as seed-coat properties, pod-wall permeability, seed and pod resistance to fungi infection , seed shriveling and cell wall permeability, will help to define the screening procedures for this characteristic. it has been one of the most important contributions that seed technology can provide for the improvement of crops grown in tropical and subtropical environments.
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