The individual and combined effects of the endogeic and epigeic groups of earthworms on the growth of Chinese cabbage (Brassica rapa), and on the subsequent growth and development of the generalist sap-sucking herbivore Myzus persicae were determined in separate pot experiments. Many previous studies have investigated the relationship between soil biodiversity and aboveground plants, but few researches have considered the indirect interaction between soil biota and above-ground aphids. In this study the individual effects of Aporrectodea rosea and Allolobophora chlorotica and the combined effects of A. rosea and A. chlorotica, Aporrectodea caliginosa and Satchellius mammalis, A. chlorotica and S. mammalis, and A. rosea, A. caliginosa, Lumbricus rubellus and S. mammalis on plant morphology and physiology and aphid development (nymphs day-1, fecundity and number of adults) were investigated. Plant growth was affected by the presence of A. rosea which caused increases in plant biomass, height of plant, leaf surface area and specific leaf area (SLA). Mean number of leaves per plant was unaffected by worm density. In contrast, increasing density of A. chlorotica had no effect on any aspect of plant performance. The combined effect of A. rosea and A. chlorotica resulted in a similar increase in plant biomass to A. rosea alone. While the combined effects of A. caliginosa and Satchellius mammalis, A. chlorotica and S. mammalis and A. rosea, A. caliginosa, L. rubellus and S. mammalis caused increases in all plant parameters except leaf number. Additionally, the individual effect of A. rosea and the combined effects of A. caliginosa and S. mammalis, A. chlorotica & S. mammalis and A. rosea and A. caliginosa, L. rubellus and S. mammalis resulted in increased in leaf nitrogen concentration. Aphid development was also affected by the presence of earthworms. The nymphs day-1, fecundity and numbers of adults were significantly increased with increases in earthworm densities. The interaction between all groups of earthworms and their influence on aphid growth showed that the combined effect of two different groups was greater than the individual groups. Proteomic techniques were used to compare protein patterns in the plants. The combined effects of A. caliginosa and S. mammalis, A. chlorotica and S. mammalis, A. rosea, A. caliginosa, L. rubellus and S. mammalis earthworms on plant resulted in differences in number and kind of protein between plant treated with earthworms and the control, but no significant difference in proteins volume. Effects of earthworms on plant growth and aphid development are shown to be modified by increasing density and interactions between different species and functional groups of earthworms.

In this study the growth and yield response of Solanum retroflexum Dun. (nightshade) and Brassica rapa L. subsp. chinensis (non-heading Chinese cabbage) to N, P and K availability in the soil and the interaction effects of these three nutrients were determined by means of pot experiments in a greenhouse. S. retroflexum was most sensitive to the availability of nitrogen in the soil. Sufficient nitrogen needed to be available to achieve optimum growth but adding too much adversely affected biomass production, suggesting a fairly narrow optimum range for nitrogen availability. The production of the crop was also dependent on the adequate availability of phosphorus and potassium but any adverse effects due to excess availability were less distinct than for nitrogen. In the case of B. rapa subsp. chinensis, an optimum availability range was identified for N and K and a critical level of availability for P. The decline in biomass production caused by adding N in excess of the optimum was reversed by applying both P and K at rates that were in excess of the respective optima.

No description available.

The overall aim of the study was to assess the risk of gene flow from Brassica crops by insectmediated pollen transport. I measured the viability of pollen in Brassica flowers throughout crop development and compared this with the viability of pollen transported by insects inside and outside one early- and one late-season crop. In order to evaluate the relative importance of different species in pollen transport, I measured abundance of flower visitors during crop development, and measured the foraging behaviour of five key pollinator species throughout the growing season, in relation to variation in microclimate, crop phenology and the relative abundance of other pollinator species competing for flower resources. Flower visiting insects of Brassica rapa crops were highly diverse, and their abundance and diversity changed with crop phenology. I found similar abundances at the family level for both crops studied, although capture rates were greater in the early- than in the late-season crop. Across flowering development, the greatest numbers of insects were captured at the peak of flowering for both crops. During the flowering period, Diptera was the most abundant order collected, followed by Hymenoptera. The most abundant family in Hymenoptera was Apidae which tracked crop development in both fields, with greater numbers of insects captured inside than outside the field. Standardized-count pollen loads were smaller in Diptera than in Hymenoptera. Of the five key pollinator species sampled, Lasioglossum sordidum (Hymenoptera: Halictidae), Apis mellifera (Hymenoptera: Apidae) and Bombus terrestris (Hymenoptera: Apidae) transported similar pollen loads, which were much greater than those carried by Eristalis tenax (Diptera: Syrphidae) and Melangyna novae-zealandiae (Diptera: Syrphidae). The numbers of insects captured outside of the crop were 10% and 33% of the totals captured inside for the early- and the late-season crop, respectively. The proportion of insects entering versus leaving the crop varied considerably across species, crops and trap location (i.e., whether traps were inside or 50 m outside the border of the crop). However, it is worth noting that not uncommonly more insects were attracted into the crop early in the season, staying there rather than leaving, and then when flowers started to disappear there was a massive escape of insects leaving. This research provides evidence for the influence of crop age on the foraging behaviour of key pollinators and for species-specific variation in the foraging behaviour of Brassica visitors with crop development. Temporal variation in the rate and variability of movement between flowers, and the duration and variability in time spent on each flower, throughout the growing season differed markedly between pollinator species. Flower density, plant density, and the abundance of other insects contributed to the observed variation in pollinator behavioural activity for A. mellifera, E. tenax, M. novae-zelandiae and L. sordidum. Bombus terrestris had the greatest rates and variability of movement, and the greatest rates of flower visitation among all key pollinators studied. Therefore B. terrestris might contribute to gene flow to a greater extent than other key pollinators. Additionally B. terrestris had the greatest variability in the rate of movement, increasing the risk of pollen movement over long distances. In summary, I found that (i) insect abundance and diversity changed with crop phenology and Diptera was the most abundant order collected, (ii) flower density, plant density, and the abundance of other insect pollinators were important factors explaining pollinator behaviour for all key pollinators, except B. terrestris, (iii) B. terrestris might contribute to gene flow to a greater extent than other key pollinators, because it has a greater rate of flower visitation and a greater flight distance between flowers than other pollinators, and (iv) pollen viability tended to decrease with crop development and declined sharply even just 50 m outside the edge of the crop.

The overall aim of the study was to assess the risk of gene flow from Brassica crops by insectmediated pollen transport. I measured the viability of pollen in Brassica flowers throughout crop development and compared this with the viability of pollen transported by insects inside and outside one early- and one late-season crop. In order to evaluate the relative importance of different species in pollen transport, I measured abundance of flower visitors during crop development, and measured the foraging behaviour of five key pollinator species throughout the growing season, in relation to variation in microclimate, crop phenology and the relative abundance of other pollinator species competing for flower resources. Flower visiting insects of Brassica rapa crops were highly diverse, and their abundance and diversity changed with crop phenology. I found similar abundances at the family level for both crops studied, although capture rates were greater in the early- than in the late-season crop. Across flowering development, the greatest numbers of insects were captured at the peak of flowering for both crops. During the flowering period, Diptera was the most abundant order collected, followed by Hymenoptera. The most abundant family in Hymenoptera was Apidae which tracked crop development in both fields, with greater numbers of insects captured inside than outside the field. Standardized-count pollen loads were smaller in Diptera than in Hymenoptera. Of the five key pollinator species sampled, Lasioglossum sordidum (Hymenoptera: Halictidae), Apis mellifera (Hymenoptera: Apidae) and Bombus terrestris (Hymenoptera: Apidae) transported similar pollen loads, which were much greater than those carried by Eristalis tenax (Diptera: Syrphidae) and Melangyna novae-zealandiae (Diptera: Syrphidae). The numbers of insects captured outside of the crop were 10% and 33% of the totals captured inside for the early- and the late-season crop, respectively. The proportion of insects entering versus leaving the crop varied considerably across species, crops and trap location (i.e., whether traps were inside or 50 m outside the border of the crop). However, it is worth noting that not uncommonly more insects were attracted into the crop early in the season, staying there rather than leaving, and then when flowers started to disappear there was a massive escape of insects leaving. This research provides evidence for the influence of crop age on the foraging behaviour of key pollinators and for species-specific variation in the foraging behaviour of Brassica visitors with crop development. Temporal variation in the rate and variability of movement between flowers, and the duration and variability in time spent on each flower, throughout the growing season differed markedly between pollinator species. Flower density, plant density, and the abundance of other insects contributed to the observed variation in pollinator behavioural activity for A. mellifera, E. tenax, M. novae-zelandiae and L. sordidum. Bombus terrestris had the greatest rates and variability of movement, and the greatest rates of flower visitation among all key pollinators studied. Therefore B. terrestris might contribute to gene flow to a greater extent than other key pollinators. Additionally B. terrestris had the greatest variability in the rate of movement, increasing the risk of pollen movement over long distances. In summary, I found that (i) insect abundance and diversity changed with crop phenology and Diptera was the most abundant order collected, (ii) flower density, plant density, and the abundance of other insect pollinators were important factors explaining pollinator behaviour for all key pollinators, except B. terrestris, (iii) B. terrestris might contribute to gene flow to a greater extent than other key pollinators, because it has a greater rate of flower visitation and a greater flight distance between flowers than other pollinators, and (iv) pollen viability tended to decrease with crop development and declined sharply even just 50 m outside the edge of the crop.

Submitted by DOGLAS BASSEGIO null (doglas14@hotmail.com) on 2017-04-16T22:03:40Z No. of bitstreams: 1 Tese.pdf: 1143011 bytes, checksum: f84f0671d7fde4c59ee46871a3d37883 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-18T17:47:05Z (GMT) No. of bitstreams: 1 bassegio_d_dr_bot.pdf: 1143011 bytes, checksum: f84f0671d7fde4c59ee46871a3d37883 (MD5) / Made available in DSpace on 2017-04-18T17:47:05Z (GMT). No. of bitstreams: 1 bassegio_d_dr_bot.pdf: 1143011 bytes, checksum: f84f0671d7fde4c59ee46871a3d37883 (MD5) Previous issue date: 2017-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O gênero Brassica é a terceira maior fonte de óleo vegetal do mundo, com oleaginosas cultivadas no Hemisfério Norte. No Brasil, apesar do aumento nos últimos anos, a espécie Brassica napus L., não é um cultivo tradicional, devido as limitações de fotoperíodo e altas temperaturas. Outras espécies do gênero, como é o caso da Brassica juncea L. e Brassica rapa L., amplamente cultivadas em zonas de baixa precipitação e fertilidade, podem ser opções de cultivo em áreas marginais de sequeiro em condições tropicais, visto que possuem alto teor de óleo com características propicias para o biodiesel, além de menor sensibilidade ao ambiente. Os objetivos deste trabalho foram caracterizar germoplasma de Brassica juncea L. e Brassica rapa L., avaliar o potencial produtivo e a divergência genética de acessos em Botucatu – SP, Brasil. Os experimentos tiveram início em outono-inverno de 2012, com a avaliação de 424 acessos de Brassica juncea L. e 209 de Brassica rapa L. quanto ao florescimento e produção de sementes. Em outono-inverno de 2015 e 2016 acessos de brássicas e um híbrido comercial da espécie Brassica napus L. foram avaliados, em experimentos em blocos ao acaso com três repetições, em relação aos componentes da produção, à produção grãos e óleo e a divergência genética. Do total de acessos introduzidos e avaliados, apenas 51 (12%) de Brassica juncea L. e 59 (28%) de Brassica rapa L. produziram sementes, devido ao efeito de fotoperiodo. Os componentes da produção variaram entre acessos e espécies, com destaque para precocidade e teor de óleo de acessos da espécie Brassica rapa L.; e o número de síliquas e a produtividade de grãos e óleo de acessos da espécie Brassica juncea L.. A produtividade de grãos e óleo foi em média 15% superior nos acessos de Brassica juncea L. em relação a espécie Brassica rapa L., com destaque para o acesso PI 180266 com 2056 kg ha–1 de grãos e 805 kg ha–1 de óleo. A variabilidade genética entre os acessos de brássicas possibilitou a formação de grupos de acessos para futuros ganhos em melhoramento genético. Conclui-se que os acessos selecionados confirmam a hipótese do potencial produtivo sem efeito de fotoperíodo em condições tropicais, o que demonstra que podem ser opções para cultivo em áreas onde a Brassica napus L. não está bem adaptada. / Brassica is the third largest source of vegetable oil in the world, with oilseeds grown in the Northern Hemisphere. In Brazil, despite the increase in recent years, Brassica napus L., is not a traditional crop due to limitations of photoperiod and high temperatures. Other species of the genus, such as Brassica juncea L. and Brassica rapa L., widely cultivated in low rainfall zones and fertility, may be cultivation options in marginal rainfed areas under tropical conditions, since they have high oil content with characteristics conducive to biodiesel, in addition to lower sensitivity to environment. The objectives of this work were to characterize the germplasm of Brassica juncea L. and Brassica rapa L. and to evaluate the productive potential, as well as the genetic divergence of accesses in Botucatu – SP, Brazil. The experiments started in autumn-winter of 2012, with the evaluation of 424 accessions of Brassica juncea L. and 209 of Brassica rapa L. regarding flowering and seed production. In the autumn-winter of 2015 and 2016, Brassica napus L. and commercial Brassica napus L. were evaluated in randomized blocks with three replicates, in relation to the production components, grain and oil production, and divergence genetic. Of the total number of accesses introduced and evaluated, only 51 (12%) of Brassica juncea L. and 59 (28%) of Brassica rapa L. produced seeds, due to the effect of photoperiod. The components of the production varied between accesses and species, with emphasis on precocity and oil content of Brassica rapa L.; and the growth and number of siliques of the specie Brassica juncea L. The yield of grains and oil was on average 15% higher in the accessions of Brassica juncea L. in relation to the species Brassica rapa L., with emphasis on access PI 180266 with 2056 kg ha–1 of grains and 805 kg ha–1 of oil yield. The genetic variability among the accessions of brassicas allowed the formation of groups of accessions for future gains in genetic improvement. It is concluded that the selected accessions confirm the hypothesis of the productive potential without photoperiod effect in tropical conditions, which demonstrates that they can be options for cultivation in areas where Brassica napus L. is not well adapted.

The possibility of manipulating calcium (Ca2+) and potassium (K+) levels in seeds of Brassica rapa by altering parent plant nutrition and investigating the potential for increased salinity tolerance during germination, given that considerable amounts of literature imply that greater amounts of available exogenous Ca2+ and K+ can ameliorate the effects of salinity on both whole plant growth and germination, was evaluated. The investigation consisted of four growth trials. Two preliminary growth trials suggested that seed ion manipulation was possible without affecting the overall growth and vigour of the plant. After developing suitable high and low Ca2+ and K+ nutrient solutions for growth, a trial was carried out in a growth room and greenhouse, with various substrates and the seed of a certain size category was collected for subsequent ion and salinity tolerance analysis. Seed Ca2+ and K+ was significantly affected by growth substrate and nutrient solution and data showed that a significant negative regression relationship existed between seed Ca2+, K+ and Ca2+ + K+ levels and salinity tolerance. Further experimentation using hydroponic culture attempted to remove any possible effects of substrate and also to compare size categories of seed with a view to elucidating localisation of Ca2+ and K+. Seed Ca2+ was found to be significantly altered by nutrient solution in the two different sizes tested and higher Ca2+ nutrient solution was found to increase salinity tolerance in daughter seed. One significant negative regression correlation between salinity tolerance and seed K+ concentration existed in smaller seed, but disregarding seed size in a regression analysis of seed ion content and salinity tolerance, a significant negative relationship existed between seed Ca2+, K+ and Ca2++ K+. The results, especially in terms of Ca2+ nutrition, contradict much previous research that suggests increased salinity tolerance at germination can arise with the increased presence of Ca2+ and/or K+. Salinity tolerance was greater in seeds of larger size across all nutritional treatments and the smaller size range exhibited increased Ca2+ and K+ per μg seed. Ca2+ concentration in smaller seeds with greater surface area:volume ratios provided a clue to the potential localisation of Ca2+. Cross sectional staining showed that a greater proportion of seed Ca2+ may reside in the coat. This was confirmed by analysis which showed an approximate 50% split of total extractable seed Ca2+, regardless of size, between coat and embryo within a seed; the majority of which, per μg, resides in the coat. Further work looked at the relative solubility of the Ca2+ and K+ in these tissues and whole seed to look at the potential bioavailability of Ca2+ during germination from various parts of the seed. Most water soluble Ca2+ exists in the embryo and most insoluble Ca2+ exists in the coat, but coat Ca2+ was found to be ionically exchangeable and therefore bioavailable. K+ appeared mostly water soluble in embryo and coat. In line with previous whole plant research in this species, most Ca2+ is readily water soluble or ionically exchangeable in form and the possible negative effects of how increasing bioavailable Ca2+ may reduce salinity tolerance was discussed.

Molecular markers for seed quality traits including erucic acid content genes, seed coat color genes in Brassica napus and seed coat color genes in B. rapa were developed. A single base change in the Bn-FAE1.1 gene in the A genome and a two-base deletion in the Bn-FAE1.2 gene in the C genome produce the nearly zero content of erucic acid observed in canola. The single base change was detected as single nucleotide polymorphic (SNP) marker with an ABI SNaPshot kit. A multiplexing primer set was designed by adding a polyT to the 5´ primer end to increase SNP detection throughput through sample pooling. The two-base deletion in the C genome gene was detected as a sequence characterized amplified region (SCAR) marker in an ABI 3100 Genetic analyzer. To increase the throughput, one genome specific primer was labeled with four fluorescence dyes and combined with 20 different primers to produce PCR products with different fragment sizes. These multiplexed high throughput molecular markers have been successfully implemented in our canola/rapeseed breeding programs. Trigenic inheritance was observed for seed coat color in B. napus. Three Sequenced Related Amplified Polymorphism (SRAP) markers very closely linked to the three different seed coat color genes were developed. Chromosome-walking technology was used to convert the SRAP marker into a SCAR marker and a SNP marker. Subsequently, the first seed coat color gene (Bn1) marker was converted into a SCAR marker, and the second seed coat color gene (Bn2) marker was converted into a SNP marker. Digenic inheritance was observed for seed coat color genes in B. rapa. A SRAP marker was identified as being tightly linked to the major seed coat color gene (Br1). The SRAP marker was sequenced and extended sequences were obtained using chromosome-walking technology. The flanking sequences of the SRAP marker contained 24 SNPs and a 12-bp deletion position that allowed the marker to be converted into a co-dominant SNP marker and a co-dominant SCAR marker, respectively. The SCAR marker was detected in the ABI 3100 genetic analyzer with four fluorescently labeled M13 primers integrated with different SCAR primers, which permitted pooling of PCR samples for high throughput detection. / October 2007

The major objective of this study was to produce synthetic genotypes of Brassica juncea from its parental species <i> B. rapa </i> and <i> B. nigra </i> via somatic and sexual hybridization. As prerequisites for somatic hybridization experiments, methods were developed to improve the culture of mesophyll and hypocotyl protoplasts of <i> B. nigra </i> and <i> B. rapa </i>, to obtain reliable plant regeneration from mesophyll protoplast cultures of <i> B. nigra </i>, and to fuse protoplasts of <i> B. nigra </i> and <i> B. rapa </i>. A modified Kao's medium (1977), was found suitable for the culture of mesophyll protoplasts of <i> B. nigra </i> and <i> B. rapa </i>. At a density of approximately $110\sp5$ protoplasts/ml within a culture plate insert surrounded by culture medium, mesophyll protoplast cultures of <i> B. nigra </i> accessions R890, R1819, R3392 and U1218 and <i> B. rapa </i> cvs. R500 and Wong Bok formed colonies. Genotypic differences in cell division and colony formation were observed. Hypocotyl protoplasts of <i> B. nigra </i> and <i> B. rapa </i> were successfully isolated from 6 day-old seedlings cultured in a modified Kao's medium (1977). With <i> B. nigra </i> accession R890 and <i> B. rapa </i> cv. R500, cell division and colony formation were optimal when hypocotyl protoplasts were cultured at a density of 0.5 to $1.010\sp5$ protoplasts/ml within a culture plate insert surrounded by a nurse culture of 4 to 6 day-old mesophyll protoplasts of <i> B. nigra </i>. Plant regeneration was obtained from mesophyll protoplast-derived calli of <i> B. nigra </i> accession R890 originally cultured in inserts; a shoot regeneration frequency of 8.1% was obtained on a medium containing the salts and vitamins of medium K3 (Nagy and Maliga 1976) with 3 g/l sucrose, 18.2 g/l mannitol, 2 mg/l ZR, 0.1 mg/l NAA, 10 g/l agarose, pH 5.6. For somatic hybridizatian studies, methods were developed to select out parental protoplasts using iodoacetic acid and to efficiently fuse protoplasts on the bottom of a petri dish using PEG. Twenty-nine plants were recovered from fusion experiments between mesophyll protoplasts of <i> B. nigra </i> accession R890 and hypocotyl protoplasts of <i> B. rapa </i> cv. Tobin. The somatic hybrid plants resembled natural <i> B. juncea </i>, had $2n=36$ chromosomes and had pollen viabilities ranging from 30 to 45%. Twenty-one plants, derived from one callus colony, possessed the mitochondrial and chloroplast genomes of <i> B. rapa </i>, as found in natural <i> B. juncea </i>. Eight plants, derived from another callus, had a novel cytoplasmic combination consisting of the mitochondrial genome of <i> B. rapa </i> and the chloroplast genome of <i> B. nigra </i>. Synthetic genotypes of <i> B. juncea </i> were also produced from reciprocal sexual crosses between <i> B. rapa </i> and <i> B. nigra </i>. Seventy-eight interspecific hybrid plants from the cross <i> B. rapa </i> x <i> B. nigra </i> and six hybrid plants from the reciprocal cross were identified by their morphology, pollen viability and chromosome number. The colchicine-induced allotetraploids resembled natural <i> B. juncea </i> in morphology, had 18 bivalents at metaphase I, and had between 35 and 70% pollen viability.

Molecular markers for seed quality traits including erucic acid content genes, seed coat color genes in Brassica napus and seed coat color genes in B. rapa were developed. A single base change in the Bn-FAE1.1 gene in the A genome and a two-base deletion in the Bn-FAE1.2 gene in the C genome produce the nearly zero content of erucic acid observed in canola. The single base change was detected as single nucleotide polymorphic (SNP) marker with an ABI SNaPshot kit. A multiplexing primer set was designed by adding a polyT to the 5´ primer end to increase SNP detection throughput through sample pooling. The two-base deletion in the C genome gene was detected as a sequence characterized amplified region (SCAR) marker in an ABI 3100 Genetic analyzer. To increase the throughput, one genome specific primer was labeled with four fluorescence dyes and combined with 20 different primers to produce PCR products with different fragment sizes. These multiplexed high throughput molecular markers have been successfully implemented in our canola/rapeseed breeding programs. Trigenic inheritance was observed for seed coat color in B. napus. Three Sequenced Related Amplified Polymorphism (SRAP) markers very closely linked to the three different seed coat color genes were developed. Chromosome-walking technology was used to convert the SRAP marker into a SCAR marker and a SNP marker. Subsequently, the first seed coat color gene (Bn1) marker was converted into a SCAR marker, and the second seed coat color gene (Bn2) marker was converted into a SNP marker. Digenic inheritance was observed for seed coat color genes in B. rapa. A SRAP marker was identified as being tightly linked to the major seed coat color gene (Br1). The SRAP marker was sequenced and extended sequences were obtained using chromosome-walking technology. The flanking sequences of the SRAP marker contained 24 SNPs and a 12-bp deletion position that allowed the marker to be converted into a co-dominant SNP marker and a co-dominant SCAR marker, respectively. The SCAR marker was detected in the ABI 3100 genetic analyzer with four fluorescently labeled M13 primers integrated with different SCAR primers, which permitted pooling of PCR samples for high throughput detection.