The CO2 concentration in the atmosphere is rising dramatically each year. Increases are certain to influence growth of C3 plants. This thesis focuses on the growth and development of rice (Oryza sativa L. cv. Jarrah).The major questions addressed in this thesis were whether elevated atmospheric CO2 concentrations would : 1/ increase grain yield where the soil was flooded or unflooded under conditions of varying phosphorus supply; 2/ change the timing of development; 3/ alter the partitioning of dry weight and nutrients between the roots and shoots; and, 4/ influence grain quality. The mechanisms underlying growth and developmental changes at elevated CO2 were also investigated. After experimentation, it is concluded that the grain yield of rice will increase as the atmospheric CO2 concentration rises even when phosphorus supplies are low. The largest response to rising atmospheric CO2 concentrations will occur under dryland conditions but increases of up to 60 per cent are likely in flooded rice. Importantly, there is likely to be a reduction in the life cycle of rice crops as the CO2 concentration rises. This would have the advantage that more crops could be sown in one season. The quality of the rice grain produced at high CO2 concentrations will also change, with milling quality appearance likely to improve. The cooked rice will be firmer. Experiments also showed that rice grown in flooded soil at different CO2 concentrations is an excellent system for investigating the control of plant growth and development, particularly the influence of hormones. / Doctor of Philosophy (PhD)

Made available in DSpace on 2014-06-11T19:24:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-01-30Bitstream added on 2014-06-13T19:52:13Z : No. of bitstreams: 1 barros_re_me_botfca.pdf: 437588 bytes, checksum: 2b4df54d5be3dbce851b8868e7447fc1 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Pesquisas visando a redução de perdas durante o armazenamento têm ocupado destaque em vários países. Dentro deste contexto, a avaliação da eficácia de um índice de qualidade de boa aplicabilidade, com metodologia simples e de resposta imediata visando tomadas rápidas de decisão é de suma importância. O presente trabalho, conduzido no Laboratório de Processamento de Produtos Agrícolas - UNESP, Botucatu/SP teve como objetivos: (a) testar a eficácia do índice de acidez graxa segundo diferentes fontes de deterioração de grãos de arroz, ao longo de um período de armazenamento. (b) estabelecer correspondência entre o nível de ácidos graxos livres e as classes de vigor em sementes; (c) estabelecer correspondência entre o nível de ácidos graxos livres e a classificação comercial por tipos, em grãos de arroz. A avaliação da eficácia do método da acidez graxa em grãos de arroz foi realizada em lotes danificados artificialmente (dano mecânico, térmico, por insetos e por microrganismos), e mantidos armazenados por um período de 150 dias. Como referência, foram utilizados os testes índice de acidez da farinha, rendimento de inteiros, porcentagem de infestação, análise sanitária (Blotter test) e classificação visual de trinca interna (diafanoscópio). A correspondência entre o nível de ácidos livres e as classes de vigor em sementes foi avaliada utilizando-se sementes degeneradas artificialmente, obtendo-se assim níveis diferenciados de vigor. A correspondência entre o nível de ácidos graxos livres e a classificação por tipos, em grãos de arroz, foi realizada utilizando-se amostras de arroz com as porcentagens máximas de grãos defeituosos permitidos pela legislação vigente. Utilizou-se a análise de variância de um delineamento inteiramente ao acaso, formados pelos momentos de avaliação e fontes de deterioração... / Researches aiming at decreasing losses in storage have been accentuated in several countries. Within this context, evaluation of the efficiency of a good applicability quality level with simple methodology and direct response is much important. The present study was carried out at the Agricultural Products Processing Laboratory - UNESP, Botucatu/SP, with the objective to: a) test the efficacy of fat acidity rate in different deterioration sources of rice grains in storage. B) establish a relation between the levels of free fatty acids and the seeds vigor classes; c) establish the relation between the level of free fatty acids and commercial classification through types in rice grains. The effectiviness evaluation of the fat acidity method in rice grains was done in samples of rice artificially damaged (mechanical, thermal, by insects and micro-organisms damages) and stored during 150 days. As referrence, it was used the tests of flour acidity rate, WHOLE GRAINS YIELD, infestation percentage, sanitary analysis (Blotter test) and visual classification of internal fissures (diaphanoscope). The correspondence between the free fatty acids and seeds vigor classes was assessed by using seeds artificially degenerated, obtaining different vigor rates. The relation between the level of free fatty acids and classification through types in rice grains was done by using samples of rice with the maximum percentage of blemished grains allowed by the legislation in force. It was used the variance analysis in a completely randomized outline made up by evaluation moments and deterioration sources, and, for means comparison, it was used the Turkeyþs test at 5% of probability. The results from the test of efficacy of the fat acidity method in different deterioration sources showed a significant effect of the mechanical, thermal and fungus damage treatments on the proof... (Complete abstract click electronic access below)

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20767号 / 農博第2250号 / 新制||農||1054(附属図書館) / 学位論文||H29||N5087(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 近藤 直, 教授 清水 浩, 教授 飯田 訓久 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Flooding cycle in wetland rice (Oryza sativa L.) production systems is often subject to seasonal and cultural variations which may affect the availability and uptake of nitrogen in different ways. These factors may more or less influence the physiological and growth responses of the plant. In an effort to improve productivity in rice cropping systems, two controlled environment studies and a field trial were conducted to evaluate the growth and yield responses of rice to different flooding regimes and nitrogen fertilizer management strategies. In the first glasshouse trial, an upland cultivar (GM-1) was used to study the effects of four flooding regimes and three nitrogen application rates on the tillering, yield components and grain yield of rice. The field study determined the applicability of the results of the glasshouse trial to out-door environmental conditions, with the aim of gaining further insight into the impact of nitrogen application strategy on tiller and grain qualities. Two wetland cultivars (FKR-19 and N-19) and GM-1 were used to evaluate the effects of two flooding regimes and two nitrogen topdressing patterns. The second glasshouse trial determined the effect of hydro-priming on the establishment of direct seeded rice, and the effect of flooding on aerenchyma formation in rice roots. Results of the studies showed that flooding with standing water of 5 cm above the soil surface, irrespective of when it occurred, and nitrogen application increased the number of tillers and panicles, above ground dry matter, nitrogen uptake and grain yield of rice. However, late flooding and high nitrogen application rate of 220 kg ha-1 were found to encourage the production of late tillers, thereby reducing the efficiency of nitrogen use for grain production. Nitrogen application in three split doses tended to increase plant nitrogen content at heading; it slightly increased the protein content of the grains at maturity, but reduced the amylose content of the starch granules. Nitrogen application in two split doses led to increased grain yield in non-flooded plants, while the three-split treatment increased nitrogen uptake and grain yield in the flooded plants. Flooding significantly increased aerenchyma formation in the cortical tissues of rice roots, particularly at 50 mm behind the root tips. Hydro-priming seeds for 48 h improved plant establishment by shortening the germination and emergence times, and increasing the height and dry matter accumulation of seedlings, thereby ameliorating the susceptibility of rice to flooding stress. Overall, the thesis affirmed that controlled flooding is beneficial to rice production since it enhanced the growth and yield of the plant. It further revealed that early flooding and appropriate timing of moderate nitrogen application can ensure the conservation of water and nitrogen resources, including the quality of the environment, with no significant consequence for yield and productivity of the crop. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Rice starch contains two types of glucose polymers, mainly linear amylose and hyper-branched amylopectin. Waxy rice has been characterised by the lack of amylose, the proportion of which being one of the most important parameters measured for rice quality. Germplasm collection work conducted in the Lao People’s Democratic Republic has previously demonstrated the diversity of this type of rice in terms of quality. The definition of a waxy rice variety is dependent on the meaning of amylose. The conventional method for determining amylose content has shown that waxy rice could have up to 5% amylose. However, including a 0% amylose standard in the standard curve causes the amylose content of these varieties to become 0-2%. In this work, the absence of amylose in waxy rice has been determined through three different approaches. Granule-bound starch synthase I (GBSS1), the enzyme which synthesises amylose, was not detected in waxy rice. Long linear chains associated with amylose were also not detected by size exclusion chromatography (SEC). The absence of these long chains affected functional properties of waxy rice, as indicated by the differences in viscosity curves between waxy and non-waxy rice. Moreover, these waxy varieties themselves exhibit differences in their viscosity curves, another indication of the diversity in coking properties in these varieties. A new approach, the ‘lnP(N) technique’, in analysing chain length distributions was applied to varieties with known mutations in two of the enzymes involved in the synthesis of amylopectin, and in determining gelatinisation temperature. It was determined that the presence of a novel feature, an interruption to linearity at DP 18-24, of the lnP(N) plot was found in rice samples with mutations in the alk gene, which codes for starch synthase (SS) IIa, and in samples with inactive branching enzyme (BE) IIb. Single nucleotide polymorphisms (SNPs) in the gene coding for SSIIa have been associated with lowered gelatinisation temperature. On the other hand, non-functionality of BEIIb changes the amylopectin structure such that gelatinisation temperature is increased. The novel feature of the lnP(N) plot is found when either or both SSIIa and BEIIb are non-functional. Waxy rice starch has hot-water-soluble (HWS) and insoluble (HWI) components. It has been confirmed that the soluble polysaccharides are structurally different from phytoglycogen, and are similar to amylopectin. Structural differences between the two fractions, which can account for their differences in solubility, were determined. At the level of the chain length distribution, the HWI fraction contained long chains not found in the HWS fraction. Considerable amounts of sucrose and glucose were found in the HWS fraction. At another level of structure, the degree of branching of the HWS components was higher than in the HWI fraction. On the other hand, the whole molecules of the HWS fraction were smaller than those of the HWI fraction. These structural differences between the two fractions potentially affected their physical behaviour, particularly solubility. The amount of leached material appears to be a property of the method, as varying cooking conditions changed the amount of HWS components. This amount reaches equilibrium at certain conditions, indicating the limited amount of the HWS material. On the other hand, the HWI component contains molecules that are insoluble in water, rather than molecules that solubilise slowly. Given the stability of the HWS fraction in solution, the ratio of the HWS fraction to the HWI fraction could potentially be used in measuring quality if the amount of the HWS fraction is variety-specific. However, the quantity of the HWS fraction appears to be a feature of the starch, rather than of the variety. Nevertheless, the fact that the soluble fraction is structurally and thermodynamically different from the insoluble fraction could presumably be grounds to classify the soluble component as a group of molecules distinct from amylopectin.

Orientador: Marco Antônio Martim Biaggioni / Banca: Claudio Cavariani / Banca: Flavio Meira Borem / Resumo: Pesquisas visando a redução de perdas durante o armazenamento têm ocupado destaque em vários países. Dentro deste contexto, a avaliação da eficácia de um índice de qualidade de boa aplicabilidade, com metodologia simples e de resposta imediata visando tomadas rápidas de decisão é de suma importância. O presente trabalho, conduzido no Laboratório de Processamento de Produtos Agrícolas - UNESP, Botucatu/SP teve como objetivos: (a) testar a eficácia do índice de acidez graxa segundo diferentes fontes de deterioração de grãos de arroz, ao longo de um período de armazenamento. (b) estabelecer correspondência entre o nível de ácidos graxos livres e as classes de vigor em sementes; (c) estabelecer correspondência entre o nível de ácidos graxos livres e a classificação comercial por tipos, em grãos de arroz. A avaliação da eficácia do método da acidez graxa em grãos de arroz foi realizada em lotes danificados artificialmente (dano mecânico, térmico, por insetos e por microrganismos), e mantidos armazenados por um período de 150 dias. Como referência, foram utilizados os testes índice de acidez da farinha, rendimento de inteiros, porcentagem de infestação, análise sanitária ("Blotter test") e classificação visual de trinca interna (diafanoscópio). A correspondência entre o nível de ácidos livres e as classes de vigor em sementes foi avaliada utilizando-se sementes degeneradas artificialmente, obtendo-se assim níveis diferenciados de vigor. A correspondência entre o nível de ácidos graxos livres e a classificação por tipos, em grãos de arroz, foi realizada utilizando-se amostras de arroz com as porcentagens máximas de grãos "defeituosos" permitidos pela legislação vigente. Utilizou-se a análise de variância de um delineamento inteiramente ao acaso, formados pelos "momentos de avaliação" e "fontes de deterioração"... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Researches aiming at decreasing losses in storage have been accentuated in several countries. Within this context, evaluation of the efficiency of a good applicability quality level with simple methodology and direct response is much important. The present study was carried out at the Agricultural Products Processing Laboratory - UNESP, Botucatu/SP, with the objective to: a) test the efficacy of fat acidity rate in different deterioration sources of rice grains in storage. B) establish a relation between the levels of free fatty acids and the seeds vigor classes; c) establish the relation between the level of free fatty acids and commercial classification through types in rice grains. The effectiviness evaluation of the fat acidity method in rice grains was done in samples of rice artificially damaged (mechanical, thermal, by insects and micro-organisms damages) and stored during 150 days. As referrence, it was used the tests of flour acidity rate, WHOLE GRAINS YIELD, infestation percentage, sanitary analysis (Blotter test) and visual classification of internal fissures (diaphanoscope). The correspondence between the free fatty acids and seeds vigor classes was assessed by using seeds artificially degenerated, obtaining different vigor rates. The relation between the level of free fatty acids and classification through types in rice grains was done by using samples of rice with the maximum percentage of " blemished" grains allowed by the legislation in force. It was used the variance analysis in a completely randomized outline made up by "evaluation moments" and "deterioration sources", and, for means comparison, it was used the Turkeyþs test at 5% of probability. The results from the test of efficacy of the fat acidity method in different deterioration sources showed a significant effect of the mechanical, thermal and fungus damage treatments on the proof... (Complete abstract click electronic access below) / Mestre

Rice (Oryza sativa L.) is the second most important cereal crop in Malawi. Rice productivity in the dominant (85%) rainfed ecosystem is very low, with mean yield of only 1.4 t ha-1. Farmers plant traditional landraces that have low yield potential and are susceptible to various stresses such as drought and diseases. Development and introduction of improved rice varieties, with stress tolerance traits from introduced varieties, such as the New Rice for Africa (NERICAs), could significantly increase productivity. Previous attempts to introduce high yielding irrigated varieties into the dominant rainfed ecosystem in Malawi have not been successful because farmers basically did not adopt the varieties, claiming that the varieties were lacking in grain traits that they preferred but that the traits were present in their landraces. The notable traits mentioned, through previous informal surveys, were long grains, medium to slender shape and aromatic grain with intermediate gelatinization temperature. No formal study has been conducted to ascertain the preferences, and the genetic control of the traits, including yield and yield related traits, have not been studied. The objectives of this study were to: 1) confirm farmers’ preferences for grain traits using participatory rural appraisal; 2) determine amount of genetic variability for yield and yield related traits in Malawi rice landraces, 3) determine the genetic control and correlations of grain length, grain shape and 1000-grain weight, 4) determine the inheritance of aroma and gelatinization temperature and, 5) determine the genetic control, correlations and path coefficients of yield and yield related traits, in F2 generations of Malawi rice landraces and NERICA varieties crosses. To confirm the farmers’ preferences for grain traits, a participatory rural appraisal was conducted in 2006 in two villages that were representative of rainfed rice growing areas in Malawi. The villages were Liundi and Nawanga in Machinga and Salima Districts, respectively. Qualitative and quantitative data were collected through questionnaires and discussions with 190 respondents, as well as through observations. To determine variability among Malawi rice landraces, 19 landraces were planted at Lifuwu in a Randomized Complete Block Design with three replicates in 2006. Data on plant height, days to 50% flowering, number of panicles per hill, panicle length, number of filled grains per panicle, 1000-grain weight, panicle weight, grain length and grain yield were collected and analyzed. Four Malawi rice landraces were crossed to four NERICA varieties in 2006 in a North Carolina Design II mating scheme to determine the genetic control of grain size. F1 plants were raised in 2007 and in 2008, 16 F2 populations together with their parents were planted in a Randomized Complete Block Design with three replicates at Lifuwu. Data on grain length, grain shape and 1000-grain weight were collected and analyzed. To determine the inheritance of aroma and gelatinization temperature, four Malawi rice landraces were crossed to four NERICA varieties in 2006 and F1 plants were raised in 2007. In 2008, 16 F2 populations together with their parents were planted in a Randomized Complete Block Design with three replicates at Lifuwu. Aroma and gelatinization temperature were evaluated. To determine the gene action of yield and yield related traits, four Malawi rice landraces were crossed to four NERICA varieties in 2006 in a North Carolina Design II mating scheme and F1 plants were raised in 2007. In 2008, 16 F2 populations together with their parents were planted in a Randomized Complete Block Design with three replicates at Lifuwu. Data on grain yield, the number of panicles per hill, days to 50% flowering, panicle length, panicle weight and 1000-grain weight were collected and analyzed The participatory rural appraisal confirmed that that long, slender or medium shape grains, with aroma and intermediate gelatinization temperature were the key traits preferred by farmers. Therefore the farmer preferred traits of long, slender grains, with aroma and medium gelatinization temperature, must be selected for in any high yielding varieties to be developed for the rainfed rice ecosystem. Results showed that differences were significant (P=0.05) for all the traits that were studied. Heritability estimates were low to moderate: 18.3% for panicle weight, 40.0% for panicles per hill and 56.3% for days to 50% flowering date. The high genetic variability among the landraces could be used in a breeding programme to develop improved varieties for various morphological traits. The number of panicles per hill and 1000-grain weight combined moderate heritabilities with relatively high genetic advance and therefore could be reliable traits for yield improvement. Genetic analysis of grain size showed that Malawi rice landraces were variable for all three grain size characteristics, namely grain length, grain shape and 1000-grain weight. NERICA varieties were variable for 1000-grain weight. Sixteen F2 progenies were variable for all three characteristics, and the variability was significant (P=0.05). Heritability estimates were high (45.4%) for grain length and low for grain shape (12.3%) and for 1000-grain weight (14.3%) suggesting that early generation selection would be effective for grain length. Predominance of additive gene action for grain length and grain shape suggested that early generation selection would be effective for these traits. Selection for 1000-grain weight would be more effective in later generations because of preponderance of non-additive gene action in the control of this trait. The correlation between grain length and grain shape was positive (r=0.769) and highly significant (P=0.01) suggesting that breeders would choose to select for both traits simultaneously, or they would choose one of the traits to develop varieties with long grains and medium shape. Crosses between aromatic and non-aromatic varieties had non-aromatic F1. The F2 progenies segregated into 3:1 ratio for non-aromatic: aromatic suggesting that, in the Malawi rice landraces, aroma was probably simply inherited through a single recessive gene. F1 progenies, between parents with high and intermediate gelatinization temperatures had intermediate gelatinization temperature. F2 progenies segregated into 1:3 ratios for high; intermediate gelatinization temperature in three out of four crosses suggesting control by one dominant gene. The segregation pattern in one cross was not significantly different from 3:13 ratio for high: intermediate suggesting that two dominant genes, one an inhibitor, were controlling the trait. Breeding and selecting for aroma and intermediate gelatinization temperature could be accomplished relatively easily because the traits are simply inherited. The genetic variability for yield and yield related traits was wide and significant (P=0.05) in the F2 populations of Malawi rice landraces and NERICA varieties crosses indicating that the populations would be valuable sources to develop varieties with improved yield. Panicle weight and the number of panicles per hill were positively correlated with, and had high direct effects on grain yield, therefore they could be used to indirectly select for high yield. Grain yield, the number of panicles per hill and plant height were predominantly controlled by additive gene action suggesting that bulk breeding methods would be adopted for these traits. The days to 50% flowering, panicle weight and 1000-grain weight were predominantly under the control of nonadditive gene action suggesting that hybrid development would be profitable for these traits. Faya Mpata, Faya Zidyana and NERICA 3 could be the best parents for improving yield and yield related traits because they had high general combining abilities for the traits. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Rice is an important crop ranking third after maize and wheat in Kenya. Its demand is growing at 12% per annum, while production has stagnated for quite a number of years. This situation has lead to consumption outstripping production by about 84%. There is therefore an urgent need to step up domestic production. To understand farmers’ preferences, the first survey on rice production was carried out. To supplement on this survey information, focus group discussions and key informants were incorporated to further shed more information. The farmers demonstrated their preferences for varieties that were high yielding, hybrid rice and with high nutrient use efficiency and these constituted 53.7% of their wishes. Among the crops grown by the selected farmers, rice was the most important followed by maize, however, the hectarage of maize was higher followed by rice. The farmers also identified labour costs as a factor limiting production especially for irrigated rice and thus they preferred upland rice due to its ease of production. Farmers identified land preparation, inputs, planting, weeding and harvesting as the most expensive activities. The existing varieties were viewed as being highly dependent on inputs which they could not afford. The main fertilizers used were Diammonium Phosphate (DAP), Sulphate of Ammonia (SA), Calcium Ammonium Nitrate (CAN) and NPK (23:23:0), the amounts used were low even though the farmers were aware that soil fertility was low. No studies or attempts had been carried out to determine performance of rice genotypes and their heritability parameters for adaptation to low soil nitrogen (N) and phosphorous (P) conditions identified by the farmers as a major constraint in Kenya. Since the existing genetic base was narrow, accessions were acquired to broaden the variability of the local cultivars. However, their adaptation to local conditions was important for them to be useful. Evaluation of 390 accessions showed that genotypes and soil environments were highly significant for all the ten traits studied. The degree of genetic determination (H(2)) ranged from 8.0% for 1000 grain weight to 27% for top biomass. The phenotypic coefficient of variation of genotypes ranged from 12% for days to maturity to 149% for top biomass, while, that of days to maturity ranged from 14% to 160% for top biomass. The genetic advance (GA) had values ranging from, 0.2 for phosphorous tolerance to 1081 for grain yield, while the genetic advance expressed as percent of the mean was 6% for days to maturity and 88% for top biomass. The mean values for the ten characters studied had wide variability under the four soil environments with days to maturity ranging from 188 for genotype ARCCU1Fa1-L4P3-HB under both N and P application (N+P+) to 177 for genotype CT16333(1)-CA-1-M under none N and P application (N-P-) condition. The highest yielding genotype was CT16328-CA-18-M under none N and P application with 5916 kg ha(-1). The germplasm revealed usable variability under low soil N and P adaptation and thus warrant rice improvement for traits of interest to farmers. In order to establish the genetic factors controlling upland rice adaptation to contrasting soil N and P a study was conducted to determine genotypes with better performance under the prevailing farmers’ production environments. The GCA and SCA mean squares were significant and their interactions with environment were highly significant. The GCA:SCA ratios were mostly less than 1.0 for the majority of the traits under most of the soil N and P environments, indicating preponderance of nonadditive genetic effects. The maternal and nonmaternal mean squares were significantly different from zero (P<0.05) for most of the ten traits under study, indicating influence of cytoplasm effects and cytoplasm by nuclear gene interactions, respectively. The GCA effects for the parents were significant under different experimental environments but they had both positive and negative signs indicating different directions of influencing the trait of interest. The genotypes had both specific and broad adaptation as exhibited by their diverse rankings under different environments. The relationship between leaf and grain nitrogen (N) and phosphorous (P) with actual tolerance to low and high soil N and P conditions indicated significant genotypes, environments and genotypes by environment interactions. The analysis of genetic components gave highly significant GCA and SCA mean squares for the days to heading, anthesis and maturity, phosphorous and nitrogen tolerance, top biomass, plant height, number of panicles, 1000 seed weight and grain yield under the four soil experimental environments. The general combining ability (GCA) effects for parents were significant for both F(2) and F(3) segregants for the above ten traits and under the experimental conditions. The leaf and seed N and P contents gave significant genotype mean squares values for the three mega-environments. The GCA and SCA mean squares were significant for leaf and seed N and P for the three locations. The same case was observed for GCA effects for the parents, with all the nine parents showing significant values for leaf N and P for the three locations. The GCA:SCA mean square ratios were generally larger than 1.0 values for leaf N and grain P for the three locations. This clearly manifested the predominant role of additive gene action over the dominance effects and that improvement for tolerance to low soil N and P condition was practical. The fragrance in rice is an important quality traits and an experiment was conducted to establish the association of organoleptic test and the variations in SSR marker (RM223) among the parents. Plant leaves of the parental genotypes were sampled for DNA analysis using SSR markers RM223 and RM284. The RM223 was polymorphic while, RM284 gave monomorphic results. Four alleles were detected as follows: 146, 155, 161, and 163. The GCA:SCA ratio was 1.48 indicating that the fixable additive effects were greater than the nonadditive effects in inheritance of fragrance. Test for independence using Chi-square indicated that there was no association between organoleptic and variations in SSR markers. The performance of the aromatic lines was generally lower than that of non-aromatic lines for the agronomic traits. There was negative relationship between fragrant score and other agronomic traits such as grain yield across the three soil N and P regimes. The NERICA1 was found to be a good donor for aroma based on sensory testing and can be exploited in a breeding programme. Analysis on genetic components governing grain yield was investigated using Hayman’s analysis to generate various components of variation and to elucidate their potential, utilization, and provide a thorough understanding of their role in grain yield development and improvement. The additive gene action was significant for all cases of soil N and P environments and the two mega-environments. They were also far above the dominant gene effects, indicating the need to use mass selection in the early generations of segregating populations. The narrow sense heritability (h2(ns)) for upland rice grain yield was 21.52% and 4.22% under soil P and N conditions, respectively. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.