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Search Results: 1 - 10 of 9307 matches for " Tulmann Neto "
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Domingues, Edson Tobias;Tulmann Neto, Augusto;
Scientia Agricola , 1999, DOI: 10.1590/S0103-90161999000100023
Abstract: sweet orange (citrus sinensis [l.] osbeck) is considered to be self-pollinated. nevertheless, in the presence of efficient pollinators, crossing has been demonstrated to increase fruit setting, as well as with the occurrence of good inter specific hybrids and absence of intra specific ones. as cross breeding programs for sweet oranges depend on more detailed studies, the mating system of 34 representative varieties from this species was evaluated at the citrus germplam collection of the "centro de citricultura sylvio moreira/ instituto agron?mico", cordeirópolis, sp. brazil. sixty eight % of the varieties studied set fruits under free pollination, 15% under self-pollination, and 35% and 15% by cross-pollination with minneola and troyer pollinators, respectively. only one variety set fruits in emasculated flowers. it was observed that under free pollination, varieties with stigmas above anthers and with longer pistils set more fruits. this data indicate that the predominance of allogamy in these varieties, seems to be an important factor for fruit setting.
Domingues Edson Tobias,Tulmann Neto Augusto
Scientia Agricola , 1999,
Abstract: A espécie de laranjas doces (Citrus sinensis [L.] osbeck) é citada como sendo autógama. No entanto a alogamia tem sido demonstrada pelo aumento da produ o de frutos com o uso de polinizadores eficientes, assim como pela existência de bons híbridos inter-específicos e ausência de bons híbridos intra-específicos. Como os programas de melhoramento via hibrida o sexual em laranja doce dependem de maiores estudos, buscou-se avaliar o prendimento de frutos em 34 diferentes variedades representativas da espécie, no banco de germoplasma de Citrus do Centro de Citricultura Sylvio Moreira do Instituto Agron mico de Campinas, sob diferentes tratamentos. Foi observado que 68% das variedades prenderam frutos sob poliniza o aberta, 15% sob auto-poliniza o, 35% após cruzamento com o tangeleiro Minneola e 15% delas apresentaram prendimento de fruto após o cruzamento com o citrangeiro Troyer. Apenas uma variedade prendeu fruto quando as flores foram emasculadas e protegidas. Foi ainda observado que sob poliniza o aberta ocorreu maior prendimento nas variedades que apresentaram os estigmas acima das anteras e em pistilos maiores. Estes dados podem ser indicativos da predominancia de alogamia nestas variedades, nas quais a poliniza o mostrou ser importante para o prendimento de frutos.
Induction of mutations for earliness in the soybean cultivar Paraná
Tulmann Neto A.,Alves M.C.
Brazilian Journal of Genetics , 1997,
Abstract: Mutation induction breeding through gamma ray seed treatment (22 krad) was used to obtain earliness in the soybean cultivar Paraná. Plants flowering earlier than Paraná were selected at the M3 generation. Eight mutant lines were isolated by further selections through several generations and tested in four yield trials carried out in 85/86 (Piracicaba) and 86/87 (Piracicaba, Sert ozinho and Assis) in S o Paulo State. The following data were taken in these trials: number of days to flowering, yield, total plant height and height to pod insertion, flower color, pod pubescence and seed and plant growth type. Two of the mutants are of agronomic interest because they were, on average, seven to 10 days earlier in maturity than the control in all trials. Except for shorter plant height, the other agronomic characteristics remained unaltered.
Determina??o da viabilidade de protoplastos irradiados de laranja 'pêra'
Cristofani, Mariangela;Mendes, Beatriz Januzzi;Tulmann Neto, Augusto;Ando, Akihiko;
Bragantia , 1993, DOI: 10.1590/S0006-87051993000200001
Abstract: the viability of 'pera' orange (citrus sinensis osbeck) protoplasts, submitted to different dosages of gamma radiation, was studied to determine the lethal dose (dl) 50. the analysis by fluorescence was employed using fluorescein diacetate (fda). the dilutions of fda (1:50; 1:100 and 1:150) did not show any statistical difference: then it was possible to use the 1:150 dilution in order to determine the protoplasts viability. the viability was inversaly proportional to gamma radiation and the dl 50 was about 41 gy. the non-irradiated protoplasts had their viability up to 84% when tested as soon after their isolation.
Indu??o de estruturas embriogênicas em tecidos de rizoma e pseudocaule de bananeira
Domingues, Edson Tobias;Tulmann Neto, Augusto;Mendes, Beatriz M. Januzzi;
Bragantia , 1996, DOI: 10.1590/S0006-87051996000100001
Abstract: structure formations with embryogenic capacity were induced on rhizome and pseudostem tissues of micropropagated plants of the banana (musa spp.) cultivars ma??, nanic?o e gn-60. explants obtained from these tissues were cultivated in a media as cited by schenk & hildebrandt, with staba vitamines in modified concentration by novak et al., supplemented with dicamba, a growth regulator, used at concentrations of 0, 2.0, 3.5, 6.63 mg/l. the treatments induced the formation of structures with embryogenic capacity in tissues (callus and globular structures) originated fromregions immediately above and below the meristematic apex, on the three tested cultivars. starting from these structures, cellular suspensions were obtained. these structures were cultivated and gave origin to structures similar to somatic embryos which after germination produced roots or aerial paris. germination, however, was not satisfactorily present.
Indu??o de mutante para maior altura basal em feijoeiro através de raios gama
Tulmann Neto, Augusto;Ando, Akihiko;Sabino, José Carlos;
Bragantia , 1994, DOI: 10.1590/S0006-87051994000200005
Abstract: seeds of the bean cultivar (phaseolus vulgaris l.) carioca 80 were irradiated with gamma-rays to induce mutants with higher basal height (sum of hypocotyl and epycotyl). a mutant with 1.7 time greater basal height was obtained in the m2 generation from 24 krad treatment. genetic studies showed that the mutation was a monogenic recessive allele. this is the first report of an induced mutant with this characteristic.
Viabilidade de pólen em clones de laranja pêra e outras variedades assemelhadas
Domingues, Edson Tobias;Tulmann Neto, Augusto;Teófilo Sobrinho, Joaquim;
Ciência Rural , 2000, DOI: 10.1590/S0103-84782000000100014
Abstract: sterility limits sexual hybridization, but on the other hand, it is of economic importance by inducing fewer seeds per fruit in some citrus varieties. pera sweet orange is the main cultivar in brazil, around 50% of all sweet oranges produced in the country. this variety has good processing quality as well as for the fresh market. the importance of this cultivar for the brazilian citriculture and the necessity to search for new cultivars, which combine the good characteristics from pera with others desirable agronomic characters, has induced new basic studies aiming at a better knowledge of genetics and reproduction of this elite variety. in this way, in this work, was studied the pollen viability for eleven clones of pera and five others sweet orange varieties, morphologically similar to pera, budded in rangpur lime (citrus limonia osbeck). the percentile of pollen viability was evaluated using acetic carmine stain and optic microscopy. it was observed that corsa tardia, pera olímpia and ovale san lio varieties, presented larger quantity of viable pollen, with 65.5, 57.3 and 53.6%, respectively, most of studied genotypes showed this values varying from 30 to 50%, and those that presented fewer values were pera bianchi and pera pirangi, with approximately 28% of viable pollen as well as ovale de siracusa variety, which did not present pollen.
Domingues, Edson Tobias;Tulmann Neto, Augusto;Teófilo Sobrinho, Joaquim;
Scientia Agricola , 1999, DOI: 10.1590/S0103-90161999000200002
Abstract: pollination is one of the most critical points in fruit growth and development, contributing with male gametes for fertilization and determine, greatly, fruit setting in citrus. it is necessary to evaluate male sterility in sweet orange varieties for their possible use in breeding programs. the sterility limits sexual hybridization, but on the other hand, it has economic importance in leading to fewer seeds per fruit in some citrus varieties. in order to characterize 44 sweet orange varieties (citrus sinensis [l.] osbeck) for pollen viability, anthers were collected from the varieties grafted on cleopatra mandarin. the varieties investigated represented the major sweet orange groups: acidic oranges (as 'pera' orange), low acidic oranges (as 'lima' orange), navel oranges (as 'bahia' orange) and bloody oranges (as 'rubi blood' orange). the percent of viable pollen was evaluated using acetic carmine stain under optic microscopy. the values ranged from 12.0% for 'pera sem sementes' orange to 88.8% for 'hamlin reserva' orange. the 'hamlin' clones showed the largest percent of viable pollen. absence of pollen in navel oranges, originated from 'bahia' variety was observed. the varieties 'pera', 'valência' and 'natal', which are the main sweet orange cultivars in s?o paulo state and brazil, presented low percent of viable pollen.
In vitro sensivity of fig plantlets to gamma rays
Ferreira, Ester Alice;Pasqual, Moacir;Tulmann Neto, Augusto;
Scientia Agricola , 2009, DOI: 10.1590/S0103-90162009000400017
Abstract: fig breeding programs through conventional methods are rare in many countries, e.g. brazil, since the wasp blastophaga psenes, which is responsible for the natural pollination, is not present. for these cases a low cost alternative for the breeding program is the induction of physical mutagenesis by radiation. the sensivity of fig explant buds of different sizes to gamma radiation were evaluated. fig plantlets "roxo de valinhos" already established in vitro were classified by size in 2.5 to 4.5 cm, 5 to 9 7 cm and 8 to 10 cm long, and irradiated with: 10, 20, 30, 40 and 50 gy doses. after irradiation each plantlet was cut in pieces containing one-bud and transferred to wpm culture medium, according to the bud position: medium and apical. explants were grown in a growth room for 90 days when, explant mortality, root formation, height of aerial part, number of buds and plantlet weight were evaluated. doses of up to 50 gy do not cause plantlet death and that doses larger than 30 gy inhibit root formation. therefore, the 30 gy dose may be recommended for the irradiation of fig plantlets larger than 2.5 cm.
Domingues Edson Tobias,Tulmann Neto Augusto,Teófilo Sobrinho Joaquim
Scientia Agricola , 1999,
Abstract: Uma vez que a poliniza o é um dos pontos decisivos para o crescimento e desenvolvimento do fruto, contribuindo com os gametas masculinos para a fecunda o e determinando, na maioria das vezes, a fixa o dos frutos em citros, torna-se necessário conhecer o grau de esterilidade masculina nas diferentes variedades de laranja doce para sua possível utiliza o em programas de melhoramento. A esterilidade é limitante para programas que envolvam a hibrida o sexual, por outro lado possui sua importancia econ mica em citros induzindo menor número de sementes por fruto em certas variedades. Com a finalidade de caracterizar 44 variedades de laranja doce (Citrus sinensis [L.] osbeck) quanto à viabilidade do pólen, foram coletadas anteras das variedades enxertadas sobre tangerineira Cleópatra. As variedades estudadas pertencem aos principais grupos de laranja doce: com acidez (como a laranja 'Pêra'), de baixa acidez (como a laranja 'Lima'), com umbigo (como a laranja 'Bahia') e sangüíneas (como a laranja 'Rubi Blood'). O percentual de pólen viável foi avaliado por meio da colora o com carmim acético a 25% e contagem sob microscópio ótico. Foram observados valores que variaram desde 12,0% para a 'Pêra Sem Sementes' até 88,8% para a variedade 'Hamlin Reserva'. Os clones de laranja 'Hamlin' mostraram maior percentual de pólen viável. N o foi observada presen a de pólen para as variedades produtoras de laranjas de umbigo, originadas da variedade Bahia. As variedades 'Pêra', 'Valência' e 'Natal', as quais s o as principais cultivares da citricultura paulista e nacional, apresentaram baixos percentuais de pólen viável.
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