M. F. Braga

Variabilidade genética de acessos silvestres e comerciais de Passiflora edulis Sims. com base em marcadores RAPD

There are a great diversity of colors, sizes and aromas of fruits in wild accessions of P. edulis in Brazilian Savannah. These accessions are also important resistance sources against illness which can be incorpored in passionfruit breeding programs. In this work, the objetive was to evaluate the genetic variability in wild and commercial P. edulis accessions using RAPD markers. The genomic DNA of each accession was extracted and amplified using thirteen decamer primers (OPD-04, OPD-07, OPD-08, OPD-16, OPE-18, OPE-20, OPF-01, OPF-14, OPG-05, OPG-08, OPH-04, OPH-12 and OPH-16) to obtain RAPD markers. These markers were transformed in binary matrix data to estimate genetic distances among accessions and to perform cluster and graphical dispersion analysis. A total of 187 markers were generated, and only 28 (14.97%) of them were monomorphic. The genetic distances among the 15 P. edulis accessions varied from 0.091 to 0.496. The molecular markers demonstrated the high genetic variability of the wild and commercial P. edulis accessions. The accessions with yellow fruits presented greater genetic distances in relation to the accessions with purple fruits. Lower genetic distances were verified among the accesses of the same geographical origin.

Reação a doenças e produtividade de um clone de maracujazeiro-azedo propagado por estaquia e enxertia em estacas herbáceas de Passiflora silvestre

Diseases induced by soil-borne pathogens cause expressive losses in passion fruit crops in Brazil. The use of resistant rootstocks could be an alternative to control these diseases. Passiflora nitida is one of the wild species of Passifloraceae, which have presented resistance to these diseases, but its utilization as seedling rootstock has been limited mainly due to differences of thickness between rootstock and the graft of the commercial cultivars. This problem can be solved by using grafting on rootstock of rooted-herbaceous cuttings and hypocotyledonary grafting, but data about the performance and yield of grafted passion fruit in field conditions are yet scarce in Brazil. The objective of this work was to evaluate the reaction to disease attack, yield and physical characteristics of fruits from a commercial passion fruit clone propagated by rooted cuttings, by grafting on rooted cuttings of a wild P. nitida (source EC-PN 1) and by seeds. The plants were cultivated in a red-yellow latosol with a drip irrigation system and oriented on a vertical espalier of 1,90 meters high. Harvest occurred weekly during 14 months and disease eva1uations were carried out at 17, 18 and 19 months after the planting. Plant yields from rooted cuttings were twice greater than those from grafted plants or seedlings. The plants propagated by grafting and rooted cuttings were lesser affected by diseases.

Confirmação de híbridos interespecíficos artificiais no gênero passiflora por meio de marcadores RAPD

The generation of passion fruit interspecific hybrids is interesting to improve agronomic traits of Passiflora edulis commercial species in genetic breeding programs, in generation of new genetic materials to use as rootstock and as alternative ornamental plants. In this work, 17 interespecific hybrids were obtained and RAPD molecular markers were utilized to confirm the interspecific hybridizations. Genomic DNA samples of each supposed hybrid and its putative genitors were extracted and amplified using 12 decamer primers to obtain RAPD molecular markers. These markers have been analyzed concerning the presence of informative bands for confirmation of the crossed fertilization. The crossing between P. laurifolia x P. nitida; P. edulis f. flavicarpa GA2 x RC1 (GA2 x P. coccinea); P. caerulea x P. amethystina; P. glandulosa x P. galbana; P. coccinea x P. actinia; P. glandulosa x P. edulis f. flavicarpa GA2; P. sidaefolia x P. actinia; P. galbana x P. actinea; F1 (P. coccinea x P. setacea) x P. coccinea; F1 (P. coccinea x P. setacea) x P. mucronata; P. eichleriana x P. gibertii; P. galbana x P. edulis f. flavicarpa GA2; P. glandulosa x P. edulis edulis Cinza TO; P. glandulosa x P. sidaefolia; P. coccinea x P. setacea were confirmed. Thus, it was verified the genetic compatibility between these species, being possible to use them in breeding programs. RAPD markers have revealed themselves as excellent tools to verify the occurrence or not of crossed fecundation in Passiflora.

Variabilidade genética de acessos obtidos de populações cultivadas e silvestres de maracujazeiro-doce com base em marcadores rapd

Sweet passion fruit (Passiflora alata Curtis) is gaining importance in the in natura fruit market due to differential value. Genetic breeding is crucial to improve crop quality and productivity. Molecular markers of DNA have been very useful by allowing obtaining a virtually unlimited number of genetic polymorphism without environment influence. This works objective was to study the genetic variability of 17 sweet passion fruit accesses, using RAPD molecular markers. One access of P. quadrangularis and another of P. edulis were used as outgroups. Genomic DNA samples of each one of them were extracted and 11 decamers primers (OPD 04, 07, 08 e16; OPE 18 and 20; OPF 01 and 14; OPG 08; OPH 12 and 16) were used to obtain the markers. The markers have been converted into a matrix of binary data, used as base to estimate genetic distances between accesses and to perform grouping and graphic dispersion analysis. From the total amount of markers, considering only P. alata accesses, it was observed 87 (62.12%) polymorphic bands, showing great intraspecific variability. Grouping analysis based on genetic distances allowed to subdivide 17 P. alata accesses in, at least, five groups of genetic similarity. The wild accesses contributed the most to the genetic basis expansion of the studied materials, opening good prospects for their use in breeding programs.

Enraizamento de estacas de três espécies silvestres de Passiflora

Em ambiente com nebulizacao controlada, estacas herbaceas com um par de folhas, contendo 2 ou 3 nos, foram testadas quanto ao enraizamento, utilizando-se de bandeja de poliestireno com celula de 95cm3 e saco plastico de 15x25x0,02cm com 1.730 cm3. Foram testadas estacas de Passiflora actinia, P. serrato-digitata e P. setacea. Observou-se que P. serrato-digitata apresentou 94,3% de estacas enraizadas com brotos e 2,4% de mortalidade; enquanto P. actinia e P. setacea apresentaram, respetivamente, 30,5% e 28,6% de estacas enraizadas com brotos e 56,8% e 60,7% de mortalidade. A alta mortalidade das estacas foi atribuida ao estado fenologico das matrizes de P. actinia e P. setacea e ao ataque de larvas de bradisia (Bradysia spp.) Estacas com dois e tres nos nao apresentaram diferencas significativas, e o recipiente saco plastico de 1.730 cm3 proporcionou melhor desenvolvimento das mudas.

Avaliação de protocolo para obtenção de mudas micropropagadas de bananeira cv. Prata-Anã (subgrupo AAB)

The purpose of this work was to evaluate a micropropagation system to cultivar Prata-Ana, observing the main factors of efficiency and limitation in the plantlet production process. The explants were established in the medium MS, supplemented with 5mg/L BAP (benzilaminopurine), 30g/L sucrose, 8g/L agar and pH 5.7. The bud multiplication was carried out in the same medium described above and the plantlet rooting phase was done with half concentration of salt and sucrose, without plant growth regulator. Losses by bacterial contamination were higher during the in vitro establishment and by fungus in the last two subcultures. The highest multiplication rates occurred between the fourth and the fifth subcultures and at the end of the process it was observed higher proportion of plantlets between 30 and 60mm. In relation to the efficiency of the number of glasses processed per operator in the laboratory it was low in the establishment, phase first subculture and rooting, when compared with the exponential multiplication phase of the explants. Even though it was noticed losses in the acclimatization phase, it was observed the occurrence of 1% of plantlets with morphological variation.

Physical and chemical characteristics and yield of Passiflora nitida Kunth accessions from north and central regions of Brazil.

O maracuja-suspiro (Passiflora nitida Kunth) e uma especie silvestre amplamente distribuida no territorio nacional. Tem alto potencial para o melhoramento visando a resistencia a diversas doencas que provocam perdas expressivas em cultivos comerciais de maracuja-azedo (Passiflora edulis Sims). Seus frutos sao comestiveis e tem elevado valor comercial como fruta fresca. Dessa forma, esse estudo teve como objetivo analisar as caracteristicas fisicas e quimicas dos frutos e determinar, em condicoes de campo, o rendimento de dez acessos de P. nitida procedentes de estados e/ou de diferentes tipos fitofisionomicos das regioes Centro - Norte do Brasil. O experimento foi conduzido na Embrapa Cerrados, localizada em Planaltina, Distrito Federal. Os acessos avaliados foram coletados em Manaus-AM, de capoeira; no Nucleo Rural Sao Jose - DF, de chapada e de vereda; no Vale do Amanhecer - DF, de vereda; Jardim Botânico-DF, de Cerrado Stricto Sensu; em Silvânia-GO, de mata ciliar e de chapada; em Itiquira - MT, de Cerrado Stricto Sensu; em Alto Paraiso-GO, de chapada, e em Natividade-TO, de chapada. O delineamento estatistico foi em blocos casualizados, com quatro repeticoes e tres plantas uteis por repeticao. As plantas foram propagadas por estacas enraizadas de cada acesso e conduzidas em espaldeiras verticais de 1,80 metro de altura, com irrigacao por gotejamento. As avaliacoes foram feitas durante as colheitas de 2006 e 2007. O acesso do Vale do Amanhecer apresentou o melhor rendimento de frutos. Este acesso pode ser usado no programa de melhoramento visando a insercao de P. nitida no mercado. Tambem foi possivel observar que as fontes provenientes do Cerrado tem caracteristicas fisicas mais desejaveis, produzindo frutos maiores e com melhor rendimento em polpa. Por outro lado, o acesso do Amazonas teve a menor espessura da casca, caracteristica desejavel para o mercado de frutas naturais.

Enraizamento de espécies silvestres de maracujazeiro utilizando cinco doses de ácido indolilbutírico

The aim of this work was to evaluate under greenhouse conditions, the rooting potential of different wild species of passion fruit using different doses of indolebutyric acid. Herbaceous cuttings of adult plants of Passiflora setacea, P. coccinea, P. amethystina, P. edulis, P. edulis x P. setacea and P. coccinea x P. setacea were collected and treated with doses of 0, 250, 500, 750 and 1000 mgL-1 of IBA, and then planted in trays with moistened substrate and held under intermittent mist. The experimental design was in randomized blocks with 5 replications and 6 x 5 factorial arrangement (six species and five IBA levels) and 6 useful cuttings per experimental unit. The variables observed were rooted living cutting with sprouts (RLCWS), rooted living cutting without sprouts (RLCWOS), living cutting with callus (LCWC), living cutting without callus (LCWOC), total of rooted cuttings (TRC), dead rooted cutting (DRC), dead cutting with callus (DCWC), dead cutting without callus (DCWOC), total of dead cuttings (TDC), cutting with sprouds (CWS), average cuttings with sprouts (ACWS), root dry matter (ROOTDM), sprout dry matter (SPRDM),and total of dry matter (TOTALDM). The P. amethystina species presented better development than other species, showing rooting potential, with 88.67% of cuttings with roots and sprouts. The use of IBA was efficient as the doses were increased, providing a good development for cuttings of the studied species.