Browsing by Subject "Purgiernuss"

Now showing 1 - 3 of 3

Characterization and management of Jatropha curcas L. germplasm
(2018) Senger, Elisa; Melchinger, Albrecht E.
Jatropha curcas L. (jatropha) is a perennial plant of the Euphorbiaceae family that grows in the tropics and subtropics worldwide. Jatropha is targeted to be grown in marginal environments. The seeds are used mainly for production of food products and bioenergy, amongst others. Jatropha breeding is at an early stage. The first obstacle is to generate competitive cultivars for economically feasible cultivation. Mayor breeding objectives are to increase seed yield and yield stability, to decrease production costs, and to improve product quality adapted to specific markets. Jatropha breeding needs to be optimized in several research areas, such as methods and tools for germplasm characterization and breeding techniques, while considering requirements of the agronomic management and product processing. The germplasm can be separated into two naturally occurring germplasm pools that differ in the presence of phorbol esters (PE). These chemical compounds have antinutritional effects on humans and animals and cannot be inactivated or eliminated from the plant material on an industrial scale yet. Therefore, food production is based on cultivars lacking PE, while bioenergy production is less affected from PE presence. The germplasm needs to be characterized and grouped depending on breeding objectives and strategies. Tools for identification of plants that synthesize PE exist, but bear decisive disadvantages or need to be advanced. These tools are exploited for germplasm management and food safety strategies. The objectives of this study were to i) examine the variation of relevant traits among genotypes and between germplasm pools, ii) estimate phenotypic and genotypic trait correlations, iii) investigate location effects and genotype by environment interactions, iv) investigate parental and heterotic effects of genotypes from different germplasm pools as well as the effect of the mating type on expression of relevant traits, and v) develop recommendations for implementation of the findings in jatropha breeding programs. In the first two publications, stress response was investigated. Leaf chlorophyll content (SPAD) was used as a dynamic trait that can be influenced by e.g. water stress and nutrient deficiency. Different genotypes were screened at several locations and at different time points. High genetic diversity was found not only in stress response but also in SPAD value. The fast and non-destructive method is highly promising to be applied in further screenings or stress response studies. In the second publication, genotypic differences in aluminum tolerance were found among seedlings in a greenhouse trial. The rapid test method is applicable in further screenings. However, it needs to be proven that aluminum tolerance at the seedling stage observed under greenhouse conditions is expressed also at later plant developmental stages in the field. In the consecutive three publications, several traits were assessed on seeds and seedlings to detect significant differences between genotypes and/or between germplasm pools. Such traits would be highly valuable for germplasm management. We found that random variation is a disadvantage of quantitative traits and hinders clear assignment of each experimental unit to the respective germplasm pool. Thus, qualitative traits might be favored, such as the “silver shimmer inside the seed testa” that differentiated toxic from non-toxic seeds with a low error rate. However, these results need to be validated. Another application area of the investigated traits is the identification of self-fertilized material within hybrid progeny. In our study, self-fertilized seeds could be differentiated from cross-fertilized ones in specific genotype combinations. Similarly, many seedling traits showed heterotic effects. In the sixth publication, genotype by environment interactions were investigated and recommendations for breeding programs elaborated. A large set of genotypes was grown for four years at three different locations. We showed that selection at only one testing location is highly risky because cultivars with low yield stability could be selected. Therefore, it is indispensable for breeders to work in a network of testing locations that differ in edapho-climatic conditions and apply appropriate experimental designs and statistical tools. In the final publication, several parameters related to the nutritional value of kernels of non-toxic genotypes grown at two locations were assessed. The high nutritional value of this material was presented and compared to soybean, peanut, hazelnut, and corn. Furthermore, preliminary conclusions related to location effects and product processing were drawn. The findings of this thesis contribute to characterization of this novel crop with regard to stress tolerances, seed and seedling characteristics as well as food quality, and help to increase breeding efficiency by presenting simple methods for fast genotype screening as well as grouping of germplasm and by efficient exploitation of testing facilities.
Jatropha meal and protein isolate as a protein source in aquafeed
(2011) Kumar, Vikas; Becker, Klaus
As aquaculture continues to develop, there will be an increasing need to use alternative plant proteins in aquaculture diets so that aqua eco-systems will be sustainable. Jatropha (DJKM, H-JPKM and DJPI) can be used as protein rich sources in the diets of fish and shrimp. There is a high potential for the safe use of DJKM, H-JPKM and DJPI in diets for fish and shrimp without compromising performance, provided that these ingredients are free of toxic factors. The detoxification process developed in Hohenheim is simple and robust and produces products that are safe and of good quality. Their addition to fish and shrimp diets gave excellent performance responses without any ill effects on animal health or safety. Effects on growth and nutrient utilization: ? Detoxified Jatropha kernel meal, H-JPKM and DJPI could replace 50%, 62.5% and 75% fish meal protein respectively without compromising growth performance and nutrient utilization in fish. In addition, DJKM could also replace 50% fish meal protein with no adverse effects on growth and nutrient utilization in shrimp. If the replacement levels are exceeded, the producer must examine the nutrient profile of the feeds carefully to ensure that desired production levels can be achieved and fish and shrimp health maintained. ? High inclusion (>50% fish meal protein replacement) of DJKM decreased the efficiency of conversion of feed to body mass. This could be explained partly by the increased mean feed intake which was possibly a reaction to the reduced protein retention, measured as protein efficiency ratio and protein productive value. No such effects were seen with the use of DJPI in common carp diets. ? Increased DJKM inclusion in diets caused a significant lowering of protein, lipid and energy digestibilities. No such effects were seen when DJPI was used in common carp diets. Effects on energy budget: ? Feeding DJKM and H-JPKM to common carp and Nile tilapia respectively did not change the major components of the energy budget (routine metabolic rate, heat released and metabolisable energy) compared to fish meal and soybean meal fed groups. These results revealed that dietary protein sources DJKM and H-JPKM can be efficiently utilized for growth by common carp and Nile tilapia respectively, as well as soybean meal and fish meal. Effects on expression of growth hormone and insulin-like growth factor-1 encoding genes ? As the level of DJKM inclusion increased in the common carp diet, growth rate decreased. The expression of Insulin-like growth factor-1 (IGF-1) in liver also decreased with increase of DJKM in the diet and that of the growth hormone in liver decreased. Effects on clinical health parameters and gut health: ? No mortality and unaffected haematological values suggested the fish were all in normal health. Alkaline phosphatase and ALT activities; urea nitrogen, bilirubin and creatinine concentration in blood were in the normal ranges which showed that there was no liver or kidney dysfunction. ? The measured plasma nutrient levels gave no indications of stress, but increasing the level of plant protein in the diet decreased plasma cholesterol. This may be related to high NSP content or reduced dietary intake of cholesterol. Decrease in muscle cholesterol level is also expected which could be considered good for human health. ? Histopathological evaluation of organs showed no damage to the stomach, intestine or liver of common carp or rainbow trout. Effects of Jatropha-phytate in Nile tilapia The defatted Jatropha kernel meal obtained after oil extraction is rich in protein (58−66%) and phytate (9 −11%). The phytate rich fraction was isolated from defatted kernel meal using organic solvents (acetone and carbon tetrachloride). It had 66% phytate and 22% crude protein and its inclusion in fish diets showed the following: ? Negative effects on growth performance, nutrient utilization and digestive physiology (nutrient digestibility and digestive enzymes). ? Adverse influences on biochemical entities such as metabolic enzymes (alkaline phosphatase and alanine transaminase) and electrolytes/metabolites. Salient changes include decreased red blood cell count and hematocrit content, decreased cholesterol and triglyceride concentrations in plasma and decreased blood glucose levels. The adverse effects observed may be due to the interaction of phytate with minerals and enzymes in the gastro intestinal tract, resulting in poor bioavailability of minerals and lower nutrient digestibility. The level of phytate used in the present study (1.5 and 3.0%) corresponds to 16.5% and 33.0% of DJKM in the fish diet. The DJKM at levels > 16.5% in the diet would exhibit adverse effects in Nile tilapia. Addition of phytase to the phytate containing diets would mitigate the adverse effects of at least up to 3% Jatropha phytate (or 33% DJKM) in the diet. Addition of phytase (1500 FTU/kg) in diets containing DJKM is recommended to maximize their utilization by Nile tilapia.
Physiological and growth responses of Jatropha curca L. to water, nitrogen and salt stresses
(2012) Rajaona, Arisoa Mampionona; Asch, Folkard
This thesis provides necessary and complementary information for an improved understanding of jatropha growth to guide further research to evaluate the response of jatropha to abiotic stressors and for designing plantations adapted to the plants? requirements. Given the fact that jatropha is claimed to grow on marginal lands, we studied effects of water supply, salt stress, nitrogen and air humidity as major abiotic stressors on gas exchange parameters and biomass production followed by management options for pruning the trees to positively influence biomass productivity and to contribute to optimize resource use. The effects of water availability (rainfed versus irrigated) on growth and gas exchange parameters were investigated for 4-year old jatropha grown in a semi-arid environment at a plantation site in Madagascar in 2010. The results confirmed that 1250 mm water in addition to a 500 mm rainfall did not affect biomass production and instantaneous gas exchange. Nevertheless, leaf light responses of irrigated plants were higher than that of rainfed plants. The study showed to what extent salt stress affected water use, canopy water vapour conductance, leaf growth and Na and K concentrations of leaves of 3-year old and young jatropha plants. 3-year old plants were exposed to seven salt levels (0-300 mmol NaCl L-1) during 20 days and young plants to five salt levels (0-200 mmol NaCl L-1) during 6 days. In both experiments, plants responded rapidly to salt stress by reducing water loss. The threshold value of responses was between 0 and 5 dS m-1. Leaf area increment of young jatropha had a threshold value of 5 dS m-1 implying that jatropha is sensitive to external salt application in terms of canopy development, conductance and CO2 assimilation rate. Transpiration of plants in both experiments was reduced to 55% at EC values between 11 and 12 dS m-1 as compared to non-stressed plants. These findings indicate that jatropha responds sensitive to salt stress in terms of leaf elongation rate and consequently canopy development, and to immediate physiological responses. Leaf gas exchange characteristics of jatropha as affected by nitrogen supply and leaf age were intensively studied, as carbon assimilation is one of the central processes of plant growth and consequently a key process embedded in modelling approaches of plant productivity. This study showed that N supply effects on leaf gas exchange of jatropha leaves were small with only the treatment without nitrogen resulting in lower rates of CO2 assimilation rate and light saturated CO2 assimilation rate, nevertheless, effects of N supply on biomass formation were pronounced. Instantaneous rates of leaf gas exchange of different leaves subject to variable air humidity (atmospheric vapour pressure deficit (VPD)) were investigated. This study showed that CO2 assimilation rate (A) and stomatal conductance (gs) were correlated in a hyperbolic fashion, and that gs declined with increasing VPD. Maximal stomatal conductance of jatropha was in the range of 382 mmol m-2 s-1 and gs is predicted to be close to zero at 6 kPa. Effects of VPD, via stomatal conductance, by preventing high transpiration rates, have been demonstrated to be decisive on water use efficiency. Our findings are in this regard relevant for the estimation of water use efficiency of jatropha. The outcome further indicates favourable conditions at which stomatal opening is high and thereby allowing for biomass formation. This information should be considered in approaches which aim at quantifying leaf activity of field-grown bushes which are characterized by spatially highly diverse conditions in terms of microclimatic parameters. Microclimatic parameters can be modified by the tree structure. The reported field experiment on 4-year old jatropha indicated that the biomass production and canopy size depended mainly on primary branch length. A comparison of plants of different pruning types with regard to trunk height (43 versus 29 cm) and total length of primary branches (171 versus 310 cm), suggest that higher biomass production and greater leaf area projection was realized by trees with short trunks and long primary branches. Growth of twigs and leaves was positively correlated with total length of branches. Relative dry mass allocation to branches, twigs and leaves, length of twigs per cm of branches and specific leaf area were not affected by pruning and water supply. Trees with shorter branches had a higher leaf area density. As opposed to an allometric relationship between the average diameter of primary branches and total above ground biomass, our data suggest that these traits were not constantly correlated. Our data indicate that the length of newly formed twigs, where the leaves are attached to, can be related to the total length of already established branches. Leaf area density and relative dry mass allocation to leaves were not affected by the two pruning techniques, indicating that pruning differences in leaf area size were proportionally converted to corresponding pruning differences in the canopy volume exploited by plants. The results reported in this study are relevant for understanding jatropha growth. It helps farmers first for a better plantation management and researchers as well as contribution to future modelling purpose concerning jatropha growth under variable climatic conditions. Additionally, it should complement information for a better set of priorities in research, contribute indirectly to breeding programs and adjust agricultural policies in terms of encountering global change.