Juan M. Montes

Determination of Mycotoxin Concentration by ELISA and Near-Infrared Spectroscopy in Fusarium-Inoculated Maize

Ear rots of maize caused by Fusarium spp. reduce grain yield and produce mycotoxins, which are harmful to humans and animals. To breed maize cultivars resistant to Fusarium spp., reliable large-scale phenotyping is essential. Our objectives were to (i) examine the precision of the ELISA method for determination of important mycotoxins, namely deoxynivalenol (DON) and fumonisins (FUM), (ii) evaluate the potential of near-infrared reflectance spectroscopy (NIRS) to estimate concentrations of DON and FUM in grain produced in inoculated maize plants, and (iii) compare the efficiency of ELISA, NIRS, and visual rating of disease severity for estimation of mycotoxin concentrations. Insignificant variation was observed between duplicate evaluations of DON and FUM by ELISA, showing the high repeatability of this method. DON and FUM determinations by ELISA were more closely correlated with mycotoxin concentrations predicted through NIRS than with visual rating of disease severity. For the prediction of DON, NIRS had very high magnitude of the coefficients of determination of calibration and cross validation (R 2 = 0.90–0.88). Thus, NIRS has a promising potential to predict DON concentration in grain samples of inoculated maize genotypes evaluated in resistance breeding programs.

Domestication and Breeding of Jatropha curcas L.

Jatropha curcas L. (jatropha) has a high, untapped potential to contribute towards sustainable production of food and bioenergy, rehabilitation of degraded land, and reduction of atmospheric carbon dioxide. Tremendous progress in jatropha domestication and breeding has been achieved during the past decade. This review: (i) summarizes current knowledge about the domestication and breeding of jatropha; (ii) identifies and prioritizes areas for further research; and (iii) proposes strategies to exploit the full genetic potential of this plant species. Altogether, the outlook is promising for accelerating the domestication of jatropha by applying modern scientific methods and novel technologies developed in plant breeding.

Determination of Methane Fermentation Yield and its Kinetics by near Infrared Spectroscopy and Chemical Composition in Maize

Maize (Zea mays L.) is the most commonly used substrate for methane production through anaerobic fermentation and is gaining further importance in Germany. Laboratory assays used for the determination of methane fermentation yield (MFY), i.e. the amount of methane produced per unit of dry matter, are complex and costly. Thus, the adoption of near infrared (NIR) spectroscopy, which is already successfully used for fast and cost-effective examination of animal feeds, would remedy this problem. The objectives of this study were to examine the potential of employing NIR spectroscopy to predict MFY as measured in a discontinuous fermenter, investigate the reliability of prediction of parameters related to the kinetics of MFY and compare models based on NIR spectroscopy with that on chemical composition for reliable prediction of MFY. Samples of dried whole plant material from 55 maize genotypes, grown in six environments, were analysed for their MFY using a discontinuous fermentation assay for different fermentation times. Further, chemical composition of the samples was analysed and NIR spectra were measured. Calibration models were developed to predict MFY and related traits based on NIR spectroscopy or chemical composition. Prediction of MFY after a short fermentation time (R2 = 0.88 after five days) was better than after complete fermentation (R2 = 0.77 after 35 days). Chemical composition models were always inferior to NIR spectroscopy models and showed a strong decrease in performance to predict MFY with ongoing fermentation time. The superiority of NIR spectroscopy is most likely attributable to higher information content in the NIR spectra. The fast determination of MFY by NIR spectroscopy will enable the examination of a larger number of samples and, therefore, allow for the use of MFY in maize breeding for biogas production.

Near Infrared Spectroscopy to Measure Maize Grain Composition on Plot Combine Harvesters: Evaluation of Calibration Techniques, Mathematical Transformations and Scatter Corrections

Near infrared spectroscopy on combine harvesters (NOCH) and choppers (NOC) is used successfully in maize breeding programmes for both grain and forage in central Europe. However, it requires the development of accurate and reliable calibration models. The objectives of our study were to assess the effects of (i) calibration techniques, (ii) mathematical transformations and (iii) scatter corrections on the development of calibration models based on NOCH spectra for determination of dry matter, crude protein and starch content of maize grain. Plot combine harvesters equipped with diode-array spectrometers were used. The calibration technique was the most important factor affecting prediction ability. The importance of spectral data pre-treatment depended on the particular constituent considered. It provided no benefits for dry matter and had variable effects on crude protein and starch.

Near infrared spectroscopy on agricultural harvesters: data management and modelling

host of conceptual and logistical challenges arises when agricultural near infrared (NIR) applications are brought from batch-wise laboratory testing to continuous in-line quality control on harvesters. First, in a continuously analysed stream of grain or forage there is a complication in isolating an individual sample as the fundamental element of chemometric modelling and in checking its reference characteristics. Second, establishing, transferring and maintaining adequate calibration models under and for such conditions requires concepts and resources clearly beyond those needed for laboratory NIR applications. Finally, the data output of the respective embedded NIR instruments constitutes merely one of many aspects of the harvesting process and needs to be integrated into fi eld/farm information and management systems.

near infrared spectroscopy on agricultural harvesters: the background to commercial developments

th century, a handful of NIR researchers in North America and Europe came to the con clusion that product analysis during the harvesting process on agricultural harvest ers by means of NIR spectrometers was a technical feasibility. the commercial rel evance of this concept prompted them to take various approaches in keeping with their sphere of work, professional experi ence and interests. their approach has be come part of a concept called “on-site NIR” (on-site near infrared spectroscopy) and this article summarises the factors that have driven developments in this application.

A new near infrared spectroscopy sample presentation unit for measuring feeding quality of maize stover.

Maize stover is used to feed farm animals and the improvement of its quality is an important breeding goal. The main objective of our study was to evaluate a new near infrared (NIR) spectroscopy sample presentation unit for measuring feed quality of maize stover. In this context, we investigated the effect of engineering factors (use of glass interface and packing pressure) on the spectral repeatability and the effect of particle sizes (8cm, 6cm, 4cm, 0.5cm) on the calibration performance. The spectral repeatability was examined by calculating spectral variation among replicated spectral measurements collected without glass interface, with glass interface, and glass interface in combination with 3 kg and 6 kg of packing pressure. The effect of particle sizes was assessed for concentrations of nitrogen (N), neutral detergent fibre (NDF), ash and in vitro fermentability (G24), by examining calibration models. The spectral repeatability increased with the use of glass interface and packing pressure and calibration performance improved with a reduction in particle size. The study indicated that the new NIR sample presentation unit has a potential for preliminary screenings of maize genotypes for NDF and G24 in the stover of particular breeding programmes.

Chuta (edible Jatropha curcas L.), the newcomer among underutilized crops: a rich source of vegetable oil and protein for human consumption

Facing the worldwide increasing demand for edible oil and protein and their production deficit in many developing countries, we investigated the nutritional value of chuta (edible Jatropha curcas L.). Chuta is a perennial tropical and subtropical plant that survives in unfavorable environments. Lower inputs are required for chuta cultivation than for other crops. The oil- and protein-rich kernels can be exploited as a snack, as an ingredient for foodstuffs, or for production of edible oil and protein. We analyzed seed and kernel characteristics, the fatty and amino acid profiles, vitamin and vitamer contents, and the levels of minerals in kernels of 40 chuta genotypes and compared mean values to crops commonly used as oil and protein sources. Our results showed that chuta oil and protein have high nutritional value for humans. We concluded that chuta products can compete with products of other crops such as soybean and peanut. Chuta products can complement the diets of vegetarians and vegans, professional athletes or persons who have to restrict their consumption of carbohydrates for medical reasons. Further, chuta can be cultivated in rural areas of developing countries, where protein sources might be scarce. Oil content in kernels and other parameters investigated here can be influenced by environmental factors during plant growth and factors of the processing chain. Considering the excellent nutritional value and promising breeding opportunities to improve important parameters, we expect an expansion of the cultivation area of this underutilized crop in the near future for production of edible oil and protein.

Parental and Heterotic Effects in Jatropha curcas L. Seedlings

Jatropha curcas L. (jatropha) is an important undomesticated perennial plant with high potential for sustainable production of food and fuel in tropical and subtropical regions. However, jatropha has no breeding history and genetic improvement of this novel crop is at an early stage. Therefore, it is of utmost importance to understand the significance of parental and heterotic effects that could be exploited in hybrid combinations. The main goal of this study was to assess the parental and heterotic effects at an early plant age in seedling traits. Our objectives were to (i) examine the variation of traits among genotypes, between genetic pools and fecundation types, (ii) investigate the parental and heterotic effects on these traits, and (iii) discuss the exploitation of parental and heterotic effects in jatropha breeding programs. Genotypes from two genetic pools were used to perform intra- and interpool crosses. Data on germination time, plant height, area of cotyledon and primary leaf, chlorophyll content of primary leaf, number of leaves, and shoot dry mass were investigated. Maternal and paternal effects affected the expression of traits at the seedling stage in jatropha. The level of influence depended on the trait and the parents under consideration. Heterotic effects were present for all seedling traits. The largest heterotic effect was found in an interpool cross.

EcoNomic Aspects of on-site Applications of near Infrared Spectroscopy

Introduction P recision farming is the way of the future and will be an important long-term benefi t in feeding the world. Near infrared (NIR) spectroscopy has become well-established as a rapid and accurate method for the determination of composition of a wide range of materials in the agricultural and food industries. The fi eld is summarised in a comprehensive monograph by Roberts et al. Precision farming is a concept originally aimed at helping farmers to identify areas of different fertility within fi elds (especially with regard to nitrogen) and thereby improve the effi ciency of fertiliser purchase and application. Less fertiliser is applied to areas that are non-productive due to soil and terrain limitations, local weather fl uctuations and other factors while more is applied to areas of higher productivity. On-site NIR spectroscopy couples NIR spectroscopy with harvesting equipment and thereby provides a tool to assist precision farming by allowing the composition of crops to be analysed continuously during harvesting. Previous papers in this series have described the details of the technology. The purpose of this article is to discuss precision farming from the farmers’ perspective. Applications to forage, grain and liquid manure will be addressed. These are three completely different types of operation.