Thesis(Ph.D.(Botany)) --University of Limpopo,2019 / Genetic transformation offers great opportunities for rapidly introducing, selecting or inducing desired characteristics in various leguminous plants for breeding purposes. But, this technique remains aloof for soybean improvement due to challenges such as genotype specificity, inefficient regeneration protocols and the rapid loss of viability in seeds required to develop explants. However, the rate of seed deterioration and its influence on in-vitro plant genetic transformation differs according to the age, storage duration and moisture content of the seeds used. The moisture status of the seeds is usually high during harvesting and deterioration (loss of viability) starts to occur when seeds are stored under ambient conditions for long periods. This seed deterioration also results in a phenomenon called “recalcitrance”, which is predominantly realised in soybean. In the present study, selected soybean genotypes were analysed for: (i) the efficiency of germination using seeds stored for 0, 3, 6 and 9-months under ambient conditions (ii) the effect of seed storage on in-vitro multiple shoot induction, (iii) the competency of the selected soybean genotypes on callus induction and Agrobacterium-mediated genetic transformation and (iv) the evaluation of protein profiles of the genotypes following co-cultivation of cotyledonary node explants with A. tumefaciens. The results obtained in this study showed that, seed stored for more than 3-months had reduced rates of germination, seedling development and in-vitro shoot multiplication. In particular, seed stored for 9-months showed a significant drop in seed germination, and less than 50% overall seed germination (Dundee-42%, LS678- 49%, TGx140-2F-44% and TGx1835-10E-48%) except for LS677 and Peking with 52 and 55%, respectively. The efficiency of multiple shoot induction also decreased with the prolonged seed storage, with all genotypes recording overall decline from about 96% to 40% regeneration efficiency over this period. The mean number of induced shoots decreased from more than 10.5 to 4.2 shoots per explant, for each genotype. The results obtained clearly indicated that efficient in-vitro shoot induction depended largely on seed storage duration, viability and significantly differed according to genotype. Following the evaluation for callus induction and Agrobacterium-mediated genetic transformation frequencies, the results indicated that the responses were genotype specific. This trend was consecutively observed in all soybean cultivars used (LS677, LS678, Dundee, Peking, TGx1740-2F and TGx1835-10E). Furthermore, the responses of the genotypes were also dependent on the culture media composition,especially, plant growth regulators and antibiotics. Amongst the cultivars used, Peking demonstrated the highest callus induction capacity (more than 70%) on MS-A and the mean number of shoots induced (1.65) using cotyledonary explants co-cultivated with Agrobacterium. This was followed by LS677 (1.42 shoots), LS678 (1.40 shoots), Dundee (1.30 shoots), TGx1835-10E (0.80 shoots) and TGx1740-2F (0.75 shoots), respectively. These genotypes also demonstrated low yields of proteins, extracted using a TCA buffer, and separated by means of two-dimensional polyacrylamide gel electrophoresis. The one-dimensional and two-dimensional profiles of proteins extracted from explants infected with Agrobacterium differed significantly to those expressed without co-cultivation of cotyledonary nodes with bacteria. These observations suggested that, the infection and co-cultivation of explants with Agrobacterium may have caused the expression of new proteins. Newly expressed proteins could also be found to either promote or inhibit transgene integration and expression on the cotyledonary node explants transformed with Agrobacterium tumefaciens for trait improvement. This study has clearly demonstrated that soybean production is confronted with a myriad of stress factors, including seed storage and quality problems due to unfavourable storage duration and weather conditions, amongst others. Thus, soybean seeds used for germination, callus induction, multiple shoot induction and genetic improvement should be harvested at R8 stage after reaching physiological maturity (with 20-35% seed moisture content) to avoid any mechanical damage, shattering or loss of seed viability. / National Research Foundation

Made available in DSpace on 2016-01-26T18:56:20Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 116799 bytes, checksum: 3e8130b0b12cb48079c689686d6e6753 (MD5) Previous issue date: 2010-02-01 / Two great challenges for the sugar cane agribusiness are the reduction of the investment and of the operational cost to increase the competitiveness of the sugar and of the etanol. The improvement of the chemical and physical quality of the soil in elapsing of the years of cultivation of the cane is one of the factors that contribute to win those challenges. The objective of this work was of evaluating the effect of the row intercropping with Crotalaria juncea (Sunnhemp) and Cajanus cajan (Pigeon pea) in the productivity, technological quality and margin of industrial contribution of the ratoon sugarcane. The experiment was accomplished in Valparaíso - SP in the Usina da Barra S/A subsidiary Univalem, using the statistical delineation in randomized blocks with four repetitions each. The results demonstrated that the productivity of stems for hectare of the leguminous was similar to the control. The organic compost as only nutrition source presented the largest productivity. The technological quality was similar in all of the treatments. The treatments Compost organic, Control and Sunnhemp without compost presented Margin of Contribution Industrial fellow creatures amongst themselves and superiors to the other treatments. / Dois grandes desafios para a agroindústria canavieira são a redução do investimento e do custo operacional para aumentar a competitividade do açúcar e do etanol. A melhoria da qualidade química e física do solo no decorrer dos anos de cultivo da cana é um dos fatores que contribuem para vencer esses desafios. O objetivo deste trabalho foi de avaliar o efeito da consorciação intercalar em linha com Crotalaria juncea e Cajanus cajan na produtividade, qualidade tecnológica e na margem de contribuição industrial da soqueira de cana-de-açúcar. O experimento foi realizado em Valparaíso - SP na Usina da Barra S/A filial Univalem, utilizando o delineamento estatístico blocos completos ao acaso com quatro repetições. Os resultados demonstraram que a produtividade de colmos por hectare das leguminosas foram semelhantes à testemunha. O composto orgânico como única fonte de nutrição apresentou a maior produtividade. A qualidade tecnológica foi semelhante em todos os tratamentos. Os tratamentos Composto orgânico, Testemunha e Crotalária sem composto apresentaram Margem de Contribuição Industrial semelhantes entre si e superiores aos outros tratamentos.

Made available in DSpace on 2016-07-18T17:51:05Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 116799 bytes, checksum: 3e8130b0b12cb48079c689686d6e6753 (MD5) Previous issue date: 2010-02-01 / Two great challenges for the sugar cane agribusiness are the reduction of the investment and of the operational cost to increase the competitiveness of the sugar and of the etanol. The improvement of the chemical and physical quality of the soil in elapsing of the years of cultivation of the cane is one of the factors that contribute to win those challenges. The objective of this work was of evaluating the effect of the row intercropping with Crotalaria juncea (Sunnhemp) and Cajanus cajan (Pigeon pea) in the productivity, technological quality and margin of industrial contribution of the ratoon sugarcane. The experiment was accomplished in Valparaíso - SP in the Usina da Barra S/A subsidiary Univalem, using the statistical delineation in randomized blocks with four repetitions each. The results demonstrated that the productivity of stems for hectare of the leguminous was similar to the control. The organic compost as only nutrition source presented the largest productivity. The technological quality was similar in all of the treatments. The treatments Compost organic, Control and Sunnhemp without compost presented Margin of Contribution Industrial fellow creatures amongst themselves and superiors to the other treatments. / Dois grandes desafios para a agroindústria canavieira são a redução do investimento e do custo operacional para aumentar a competitividade do açúcar e do etanol. A melhoria da qualidade química e física do solo no decorrer dos anos de cultivo da cana é um dos fatores que contribuem para vencer esses desafios. O objetivo deste trabalho foi de avaliar o efeito da consorciação intercalar em linha com Crotalaria juncea e Cajanus cajan na produtividade, qualidade tecnológica e na margem de contribuição industrial da soqueira de cana-de-açúcar. O experimento foi realizado em Valparaíso - SP na Usina da Barra S/A filial Univalem, utilizando o delineamento estatístico blocos completos ao acaso com quatro repetições. Os resultados demonstraram que a produtividade de colmos por hectare das leguminosas foram semelhantes à testemunha. O composto orgânico como única fonte de nutrição apresentou a maior produtividade. A qualidade tecnológica foi semelhante em todos os tratamentos. Os tratamentos Composto orgânico, Testemunha e Crotalária sem composto apresentaram Margem de Contribuição Industrial semelhantes entre si e superiores aos outros tratamentos.

Made available in DSpace on 2016-06-02T18:57:44Z (GMT). No. of bitstreams: 1 4858.pdf: 1500028 bytes, checksum: 6eb4c7f69ba670ca722b5e1e34100812 (MD5) Previous issue date: 2012-05-04 / Financiadora de Estudos e Projetos / The cultivation of peppers occurs in practically all regions of the country and is one of the crops that better integration exerts between the small farmer and the agribusiness. Thus it is desirable to develop technologies that combine the production of peppers with the conservation of natural resources, allowing recovery of soils and the economic stability of families that depend on this system. The aim of this study was to evaluate the effect of species and managements of green manure on mineral nutrition, growth and productivity of pepper-pout (Capsicum chinense). The experiment was conducted in the agricultural year 2010/2011 at the Center for Agricultural Sciences, UFSCar, Araras-SP. The treatments were a combination between green manure species: bean (Canavalia ensiformis DC) and sunn-hemp (Crotalaria juncea L.), and three forms of management of green manure in consortium with pepper-pout: green manures grown throughout the cycle of pepper, green manures managed (cut) in the flowering of pepper (75 days after transplanting, DAT), green manures handled at the first harvest of the fruits of pepper (90 DAT). And one more treatment (control), only with the pepper-pout plants, with mineral fertilization. The results showed that the species Crotalaria juncea and bean-pig conducted in consortia with plants of pepper-pout, when handled at 75 days after transplanting of vegetable crop, caused an increase in height and canopy diameter of pepper and fruit yield similar to the cultivation of pepper with exclusive use of mineral fertilizer. Overall, the releases of nutrients from biomass of green manure followed the nutritional demand of pepper plantspout, regardless of the time of cutting. But the bean-pig conducted throughout the cycle of pepper reduced fruit yield, probably by competition established between green manure and pepper. / O cultivo das pimentas ocorre praticamente em todas as regiões do país e é uma das culturas que melhor exerce a integração pequeno agricultoragroindústrias. Dessa forma é desejável o desenvolvimento de tecnologias que conciliem a produção de pimentas com a conservação dos recursos naturais, permitindo a recuperação dos solos e a estabilidade econômica das famílias que dependem desse sistema. O objetivo desse trabalho foi avaliar o efeito das espécies e manejos dos adubos verdes na nutrição mineral, crescimento e produtividade da Pimenta-biquinho (Capsicum chinense). O experimento foi conduzido no ano agrícola 2010/2011 no Centro de Ciências Agrárias, UFSCar, município de Araras-SP. Os tratamentos foram constituídos pela combinação entre as espécies de adubos verdes: feijão-de-porco (Canavalia ensiformis D.C.) e crotalária-júncea (Crotalaria juncea L.), e três formas de manejo dos adubos verdes em consórcio com a Pimenta-biquinho: adubos verdes cultivados durante todo o ciclo das pimenteiras; adubos verdes manejados (cortados) na floração das pimenteiras (75 dias após transplantio-DAT); adubos verdes manejados por ocasião da primeira colheita dos frutos das pimenteiras (90 DAT). E um tratamento adicional (testemunha), cultivo exclusivo das plantas de Pimenta-biquinho com adubação mineral. Os resultados obtidos permitiram concluir que as espécies crotalária-júncea e feijão-de-porco conduzidas em consórcios com as plantas de Pimenta-biquinho, quando manejados aos 75 dias após o transplantio da olerícola, promoveram aumento na altura e no diâmetro de copa das pimenteiras, e produtividade de frutos semelhante ao cultivo exclusivo da pimenteira com uso da adubação mineral. De forma geral, as liberações dos nutrientes da fitomassa dos adubos verdes acompanharam a demanda nutricional das plantas de Pimenta-biquinho, independente da época de corte. Porém, o feijão-de-porco conduzido durante todo o ciclo da pimenteira reduziu a produtividade de frutos, provavelmente pela competição estabelecida entre o adubo verde e a pimenteira.

Herbicides have become a key component in modern agricultural production. Meanwhile, there is a concern that some herbicides persist past the growing season of the treated crop, and negatively influence the production of the subsequently planted crops. Amongst various herbicides used in western Canada, acetohydroxyacid synthase (AHAS)-inhibiting herbicides warrant special attention given their residual properties and acute plant toxicity at low concentrations in soil. Soil residual AHAS inhibitors have the potential to influence both leguminous host plants and their bacterial symbiotic partners; consequently, the use of an AHAS inhibitor in a given year can negatively influence the inoculation success and grain yield of legumes cropped in the following year. <p>The present thesis project focused on one of the AHAS inhibiting herbicides (flucarbazone) and studied its potential for carryover injury and negative influence on the success of inoculation in field pea. A series of growth chamber and field experiments were conducted to test the following null hypothesis: the presence of residual flucarbazone in soil does not affect nodulation of field pea by inoculum rhizobia. <p>A growth chamber experiment clearly demonstrated the susceptibility of field pea to the presence of flucarbazone in soil where the lowest concentration of flucarbazone amendment (5 ìg kg1) significantly reduced the crop growth. In contrast, a field study failed to reveal any negative effects of flucarbazone use on crop growth and N2 fixation. <p>It was concluded that if the weather and soil conditions favour decomposition of flucarbazone as described in the present study, flucarbazone applied at the recommended field rate will not persist into the following season at high enough concentrations to negatively influence field pea growth, grain yields, and inoculation success. To ensure safety of rotational crops, it is important to strictly adhere to the herbicide application guidelines. Additionally, producers are cautioned to be particularly aware of the environmental and soil conditions that may reduce the rate of herbicide degradation.

Herbicides have become a key component in modern agricultural production. Meanwhile, there is a concern that some herbicides persist past the growing season of the treated crop, and negatively influence the production of the subsequently planted crops. Amongst various herbicides used in western Canada, acetohydroxyacid synthase (AHAS)-inhibiting herbicides warrant special attention given their residual properties and acute plant toxicity at low concentrations in soil. Soil residual AHAS inhibitors have the potential to influence both leguminous host plants and their bacterial symbiotic partners; consequently, the use of an AHAS inhibitor in a given year can negatively influence the inoculation success and grain yield of legumes cropped in the following year. <p>The present thesis project focused on one of the AHAS inhibiting herbicides (flucarbazone) and studied its potential for carryover injury and negative influence on the success of inoculation in field pea. A series of growth chamber and field experiments were conducted to test the following null hypothesis: the presence of residual flucarbazone in soil does not affect nodulation of field pea by inoculum rhizobia. <p>A growth chamber experiment clearly demonstrated the susceptibility of field pea to the presence of flucarbazone in soil where the lowest concentration of flucarbazone amendment (5 ìg kg1) significantly reduced the crop growth. In contrast, a field study failed to reveal any negative effects of flucarbazone use on crop growth and N2 fixation. <p>It was concluded that if the weather and soil conditions favour decomposition of flucarbazone as described in the present study, flucarbazone applied at the recommended field rate will not persist into the following season at high enough concentrations to negatively influence field pea growth, grain yields, and inoculation success. To ensure safety of rotational crops, it is important to strictly adhere to the herbicide application guidelines. Additionally, producers are cautioned to be particularly aware of the environmental and soil conditions that may reduce the rate of herbicide degradation.