O tomateiro (Solanum lycopersicum L.) é uma das hortaliças mais cultivadas no mundo. No Brasil, a cultura está entre as de maior importância econômica e social. Nos últimos anos, foi detectada a incidência de uma espécie de crinivirus, Tomato clorosis virus (ToCV), nos principais estados produtores dessa hortaliça no país. O ToCV é transmitido por Bemisia tabaci biótipo B de maneira semi-persistente. O objetivo deste trabalho foi identificar hospedeiros alternativos do isolado brasileiro do ToCV, que podem atuar como fonte primária de inóculo do patógeno. Um isolado brasileiro (A JQ952600) foi inoculado em plantas sadias de 73 espécies, pertencentes a 14 famílias, por meio de B. tabaci biótipo B, em testes com e sem chance de escolha do vetor. Também foi avaliada a preferência para oviposição do vetor em testes com chance de escolha. Por último, foi feita a recuperação do vírus das hospedeiras suscetíveis infectadas para plantas de tomate por meio do vetor, em teste sem chance de escolha. A detecção do ToCV foi feita por nested- PCR a partir de RNA total extraído das amostras foliares. Foram usados os pares de oligonucleotídeos iniciadores HS-11 / HS-12 e TOC-5 / TOC-6. O amplicon específico do ToCV de 463 pb esperado foi detectado no RNA total extraído de 19 espécies pertencentes às famílias Solanaceae e Amaranthaceae. A identidade do isolado viral foi confirmada por sequenciamento de nucleotídeos de alguns amplicons. Confirmou-se a suscetibilidade de Chenopodium album, Datura stramonium, Gomphrena globosa, Nicotiana benthamiana, N. clevelandii, N. edwarsonii, N. glutinosa, N. tabacum, Solanum americanum, S. pimpinellifolium e Spinacea oleracea à infecção com o ToCV. As espécies Capsicum annuum, Physalis angulata, P. peruviana e S. tuberosum var. Asterix, relatadas como suscetíveis ao vírus no campo, foram infectadas experimentalmente. Beta vulgaris var. cicla, Chenopodium quinoa, S. aculeatissimum, S. melongena e S. sessiliflorum foram identificadas pela primeira vez como espécies suscetíveis ao ToCV. No teste de transmissão com chance de escolha do vetor, verificou-se alta suscetibilidade de quase todas as espécies à infecção com o ToCV. Também se encontrou que a grande maioria das espécies suscetíveis ao vírus exibiu boa preferência à oviposição de B. tabaci biótipo B. Porém, as espécies da família Amaranthaceae mostraram os menores valores para estas duas variáveis. No teste de recuperação do ToCV para plantas de tomate, todas as espécies identificadas como suscetíveis ao vírus mostraram ser boas fontes de inóculo do patógeno. A eliminação de hospedeiros alternativos do vírus presentes na vegetação espontânea, restos de culturas e plantas voluntarias infectadas deve ser parte das estratégias de manejo do amarelão do tomateiro. / The tomato (Solanum lycopersicum L.) is one of the most cultivated plants in the world. In Brazil, tomato crops are among the most economic and social crops. In recent years, the incidence of a crinivirus species, Tomato chlorosis virus (ToCV), in the main tomato producing states in the country has been constantly observed. The ToCV is transmitted by Bemisia tabaci biotype B in a semi-persistent manner. The aim of this study was to identify alternative hosts of the Brazilian isolate of ToCV, which can act as a primary source of inoculum of the pathogen in the field. A Brazilian isolate of the crinivirus (A JQ952600) was inoculated in healthy plants of 73 species, belonging to 14 families, through B. tabaci biotype B, in tests with and without chance of choice for the vector. It was also evaluated the preference for vector oviposition on plants used for the free choice transmission test. Finally, the recovery of the virus from susceptible species to tomato plants was carried out by B. tabaci biotype B in tests without chance of choice for the vector. The detection of ToCV was done by nested PCR from total RNA extracted from leaf samples. Primer pairs HS-11 / HS-12 and TOC-5 / TOC-6 were used. The specific amplicon of 463 bp of the ToCV was detected in total RNA extracted from 19 species of the Solanaceae and Amaranthaceae families. The identity of the virus isolate was confirmed by nucleotide sequencing of some amplicons. The results confirmed that Chenopodium album, Datura stramonium, Gomphrena globosa, Nicotiana benthamiana, N. clevelandii, N. edwarsonii, N. glutinosa, N. tabacum, Solanum americanum, S. pimpinellifolium, and Spinacea oleracea were susceptible to ToCV infection. Capsicum annuum, Physalis angulata, P. peruviana, and S. tuberosum var. Asterix, reported as susceptible to ToCV in the field, were experimentally infected. Beta vulgaris var. cicla, Chenopodium quinoa, S. aculeatissimum, S. melongena e S. sessiliflorum were for the first time identified as susceptible to infection with ToCV. The high susceptibility of the above-mentioned species was confirmed in the free choice transmission test with B. tabaci biotype B. It was also found that the vast majority of the susceptible species to the virus exhibited good preference for oviposition of B. tabaci biotype B. Except the species of the Amaranthaceae family, which showed the lowest values for both variables. For ToCV recovery test to tomato plants, all species identified as susceptible to the virus proved to be good sources of inoculum of the pathogen. The elimination of alternative hosts of the virus present in natural vegetation, abandoned crops and voluntary infected plant debris should be part of the management strategies of tomato yellowing.

Anther culture experiments were conducted to construct a monoploid family. The donor plants used were hybrids between high leptine producing selections of Solanum chacoense Bitt. and anther culture responsive selections of Solanum phureja Juz. et Buk. Several steps of the anther culture process were studied. The results indicated that genotype remains the main factor affecting anther culture response. Growing anther-donor plants in higher greenhouse temperatures (30 degrees C day/20 degrees C night) increased the number of embryos per anther by 40 percent. A heat shock given to anthers in culture for 12h at 35 degrees C was also found to be beneficial resulting in an increase of the anther culture response by 40 percent. However the effect of the high temperature shock resulted in lower regeneration rates. In all experiments a highly significant "date" effect was observed with one or two days differing from the others by showing higher response rates in all hybrids tested. The majority of the regenerated plants was diploid, probably resulting from unreduced gametes. Simple sequence repeat analysis with eight polymorphic primer pairs was used successfully to identify the homozygous diploid plants that were added to the monoploids. In total 34 monoploid plants and 14 homozugous diploids were obtained. The degree of heterozygosity revealed by SSR analysis indicated that the diploid plants originated from unreduced gametes formed by first division restitution (FDR) mechanism. The SSR marker data were used to map the genes with respect to the centromeres by half tetrad analysis. SSR-containing sequences from the public databases, as well as sequences obtained from a genomic library enriched for SSRs, were used to generate 48 primer pairs. Only 12 of them were found to be polymorphic in the monoploid family. Ten primer pairs did not amplify any specific fragment. The monoploid population showed distorted segregation at four of the polymorphic loci, showing overrepresentation of the chacoense alleles in three of them. One of the loci showing distorted segregation (STSTP, amplified by primer pair RV 11+12) is most probably linked to lethal alleles, whereas another one (ST13ST, amplified by primer pair RV 21+22) could be linked to genes affecting anther-culture response. The location of the SSR loci on the potato chromosomes is not known except for one (waxy, primer pair 3+4), but statistical analysis on the segregation data obtained from 70 heterozygous anther-derived diploids showed no linkage between them. The SSR primer pairs developed in this study might be useful in studying genetic relationships among cultivars and accessions in breeding programs. Randomly amplified polymorphic DNA (RAPD) analysis was used in association with bulked segregant analysis to detect linkage with genes controlling leptine biosynthesis. With all the limitations imposed by the population size and contamination from foreign pollen, a band amplified by primer OPA-16 could differentiate the bulks contrasting for leptine content. It is possible that this band is linked to genes suppressing leptine biosynthesis, since it appears only in the plants that do not synthesize leptines. Further investigation with larger populations is needed to confirm this possibility. / Ph. D.

published_or_final_version / Botany / Doctoral / Doctor of Philosophy

No description available.

La producción de alcohol se encuentra relacionada directamente con la producción de Biocombustibles, debido al desplazamiento de importantes volúmenes de alcohol para su conversión en etanol o alcohol anhídrido; usado como complemento o sustituto de la gasolina. Esta situación ha generado que la caña de azúcar, principal materia prima para la elaboración de alcohol se convierta en un “bien escaso” y sea necesario buscar otras potenciales fuentes para su producción. En el Perú, existe también el potencial para producir el mencionado producto, usando los tubérculos como base, especialmente la papa; a través de la conversión de almidones en azúcares y su posterior fermentación y destilación en alcohol etílico. La presente investigación tiene por finalidad demostrar la viabilidad de la instalación de una planta de producción de alcohol de papa en la provincia de Chota, departamento de Cajamarca, con la intención de atender al mercado interno, con un producto de alta calidad, orientado al uso industrial, farmacéutico y cosmético. La metodología desarrollada comprende la determinación de viabilidad de Mercado, Organizacional, Técnico Operativa, Económica financiera y ambiental. Finalmente se concluye que es viable la instalación de una planta de producción de alcohol en la provincia de Chota. / Tesis

The present study aimed to examine the effects of root colonization in tomato, Solanum lycopersicum L. cv. Moneymaker, by the arbuscular mycorrhizal (AM) fungus, Glomus intraradices Shenck and Smith, on alleviating salt stress. I postulated that AM symbiosis increases tomato plant performance to salt stress. Two greenhouse experiments were done according to a randomized factorial experimental design. The results showed a significantly higher level of AM root colonization that also occurred earlier in salt than non-salt treated plants. There were also positive interactions between root colonization levels and the alleviation of salt stress; these contributions resulted initially on higher root fresh mass (FM), later on shoot FM, and DM, and higher phosphorus and unchanged potassium concentrations in roots. The effects observed in salt-treated plants were significant when root colonization levels were significantly different than those observed in non-salt treated plants. This suggests a relationship between the level of root colonization and the alleviation of salt stress in plants. The attempt to use molecular techniques to detect early root colonization was quite successful in detecting the presence of G. intraradices in AM plants. However, it was not possible to detect the presence of the AM fungus as early as by classical root staining. This was observed presumably because sampling methods were different. In general, the results support the hypothesis that AM root colonization contributes to some extent to salt resistance of tomato plants.

The present study aimed to examine the effects of root colonization in tomato, Solanum lycopersicum L. cv. Moneymaker, by the arbuscular mycorrhizal (AM) fungus, Glomus intraradices Shenck and Smith, on alleviating salt stress. I postulated that AM symbiosis increases tomato plant performance to salt stress. Two greenhouse experiments were done according to a randomized factorial experimental design. The results showed a significantly higher level of AM root colonization that also occurred earlier in salt than non-salt treated plants. There were also positive interactions between root colonization levels and the alleviation of salt stress; these contributions resulted initially on higher root fresh mass (FM), later on shoot FM, and DM, and higher phosphorus and unchanged potassium concentrations in roots. The effects observed in salt-treated plants were significant when root colonization levels were significantly different than those observed in non-salt treated plants. This suggests a relationship between the level of root colonization and the alleviation of salt stress in plants. The attempt to use molecular techniques to detect early root colonization was quite successful in detecting the presence of G. intraradices in AM plants. However, it was not possible to detect the presence of the AM fungus as early as by classical root staining. This was observed presumably because sampling methods were different. In general, the results support the hypothesis that AM root colonization contributes to some extent to salt resistance of tomato plants.

Solanum mauritianum Scop. is rated the worst invader species in pine plantations throughout the Republic of South Africa. Control is costly and apparently ineffectual since the species is spreading in pine plantations at a rate of 16 % per annum. This is due to the high reproductive potential of the species. S. mauritianum produces fruits throughout the year. Fruit and seed yield is related to tree size. S. mauritianum produced approximately 7.2 million viable seeds per hectare during 20 months when growing under conditions unfavourable for growth. Seeds are efficiently dispersed by animals and birds. Although high seed or seedling mortality occurs, the initial prolific seed production and efficient dispersal ensures the rapid spread of this species in South Africa. Surviving seeds form the source for both further encroachment and reinfestation of areas in which S. mauritianum has been controlled. S. mauritianum seeds require the presence of both light and alternating temperatures for optimum germination. Transfer of seeds from unfavourable to optimum conditions or the application of gibberellic acid (GA [3]) can promote high germination percentages. However, the germination requirements of S. mauritianum are highly variable. Germination is influenced by site, season and year of seed shed. Seeds varied in terms of primary dormancy; conditional dormancy; the response to transfer from unfavourable to favourable conditions; the response to application of GA[3]; and the occurrence of secondary dormancy. Germination requirements of seeds were also influenced by site, duration and depth of burial. All these factors contribute to a sporadic seedling emergence over a prolonged period, which results in current control operations being both costly and ineffective. Alternative control methods were therefore considered. These included the application of herbicides or heat to kill seeds, application of various gro~th regulators to stimulate germination, and the chemical extraction of alkaloids from fruits and seeds for use in the pharmaceutical industry. Two alkaloids (solasodine and a new molecule) were extracted from green bugweed fruits growing under unfavourable conditions. Although levels of solasodine extracted were very low compared with those from commercially grown species of this genus, extraction of the second alkaloid raised the potential of the species for utilization purposes. Utilization of the reproductive propagules could reduce the continual dispersal of seeds and thereby contribute to long-term control of this species. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1990.

The present study aimed to examine the effects of root colonization in tomato, Solanum lycopersicum L. cv. Moneymaker, by the arbuscular mycorrhizal (AM) fungus, Glomus intraradices Shenck and Smith, on alleviating salt stress. I postulated that AM symbiosis increases tomato plant performance to salt stress. Two greenhouse experiments were done according to a randomized factorial experimental design. The results showed a significantly higher level of AM root colonization that also occurred earlier in salt than non-salt treated plants. There were also positive interactions between root colonization levels and the alleviation of salt stress; these contributions resulted initially on higher root fresh mass (FM), later on shoot FM, and DM, and higher phosphorus and unchanged potassium concentrations in roots. The effects observed in salt-treated plants were significant when root colonization levels were significantly different than those observed in non-salt treated plants. This suggests a relationship between the level of root colonization and the alleviation of salt stress in plants. The attempt to use molecular techniques to detect early root colonization was quite successful in detecting the presence of G. intraradices in AM plants. However, it was not possible to detect the presence of the AM fungus as early as by classical root staining. This was observed presumably because sampling methods were different. In general, the results support the hypothesis that AM root colonization contributes to some extent to salt resistance of tomato plants.

215 h. / La producción de alcohol se encuentra relacionada directamente con la producción de Biocombustibles, debido al desplazamiento de importantes volúmenes de alcohol para su conversión en etanol o alcohol anhídrido; usado como complemento o sustituto de la gasolina. Esta situación ha generado que la caña de azúcar, principal materia prima para la elaboración de alcohol se convierta en un “bien escaso” y sea necesario buscar otras potenciales fuentes para su producción. En el Perú, existe también el potencial para producir el mencionado producto, usando los tubérculos como base, especialmente la papa; a través de la conversión de almidones en azúcares y su posterior fermentación y destilación en alcohol etílico. La presente investigación tiene por finalidad demostrar la viabilidad de la instalación de una planta de producción de alcohol de papa en la provincia de Chota, departamento de Cajamarca, con la intención de atender al mercado interno, con un producto de alta calidad, orientado al uso industrial, farmacéutico y cosmético. La metodología desarrollada comprende la determinación de viabilidad de Mercado, Organizacional, Técnico Operativa, Económica financiera y ambiental. Finalmente se concluye que es viable la instalación de una planta de producción de alcohol en la provincia de Chota.