Where the work of others has been used, this is duly acknowledged in the text. However, knowledge of how environments, position of bud scales on the stem and age affect NIRS is necessary to determine the feasibility of the method. Upon acquiring the new tool, the errors generated by the old tool became apparent.
An analysis of the heritability of the chemical compounds associated with eldana resistance was also included in this study. In the rank-order analysis, correcting data to remove genotype effect reduced the number of unstable genotypes, suggesting that the G x E interaction effect was partially confounded with the bud scale mass of the genotypes. Ratoon - The above-ground components of the plant that regenerate from the root system after harvest.
The genetic control and inheritance of the chemical components that NIRS detects is also unknown. Furthermore, samples were taken from the underside of the stalk to determine whether the breakdown of the bollworm chemical components was different for different genotypes, and whether this contributed to the level of eldana resistance.
LITERATURE REVIEW
Once the recording of reflectance values is complete, the information is converted to the log of the reciprocal (Starr et al., 1981; Givens and DeaviIle, 1999). This adds to the prediction errors, especially for samples near the extremes of the calibration range. Samples that were not part of the original calibration should be predicted using the calibration equation, and compared to the reference method values (Lee et al., 1997).
Although the relative importance of the G x E interactions can be estimated, the causes and nature of the interactions cannot be determined (Shafii et al., 1992; Hohls, 1995). This limits interpretation of the data to only the environments and genotypes used in the study. Alternatively, commercial fields in adjacent areas can be used as an indication of the potential trial site (Jones et al., 1993).
Improvement to a population also requires a high variation of the character in the initial population (Hogarth, 1968; Hogarth et al., 1981; Vogel et al., 1993). This estimate has the potential to be more accurate than any of the original estimates (Hill and Nicholas, 1974). The PLS is usually better than PCA due to the inclusion of the Y information in the regression.
Within the calibration equation development system, a number of options are available for transforming the data.
CALIBRATION TRIAL
At the sixteenth and twentieth monthly sampling dates, an additional sample was taken from the lower parts of the stems in the same manner as the standard sample. Peak locations and their amplitudes were correlated with eldana resistance scores to determine if there was a relationship. Analysis of different sample sets showed very little statistical overlap between sample sets based on PCA analysis using the NIRS instrument software.
Analysis of H distances between sample sets showed that all sample sets coordinately overlapped, based on PCA analysis using the NIRS instrument software. None of the calibration techniques available in the NIRS software provided a calibration equation that could predict the values of another set of samples. The inability of the calibration equations to predict eldana resistance scores from one set of samples to another is hypothesized to be due to the influence of the environment on the spectral readings.
The non-overlapping of the samples in the original experiment also contributed to the erroneous conclusions drawn. In the best sample set example, choose to discard those clones with a rating above a. These bud scale masses were examined for correlation with eldana resistance, and were used to test the G x E interaction analyzes that would be used on the chemical profiles of the bud scales.
The average bud scale masses for the 60 cultivars in the calibration set are shown in Appendix 1. The correlation values for bud scale mass from the lower part of the stem to fire blight resistance were much better (Tables 3.5 and 3.6), having only two negative values (-0.14 and - 0.08), with a maximum of 0.31. However, nine of the 24 values exceeded 0.2, suggesting that there was a closer relationship between bud flush mass at the lower stem positions than at the top of the stem.
Mean boll scale mass was lower for the base of the stem at all sites and ages except one. There was no trend in mean bud scale mass as age increased for the top of stem buds, but older bud scales at the base of the stem tended to be lighter. An evaluation of the stability of clones on a qualitative basis is important even in disease evaluation.
A non-significant V expression indicated that none of the genotypes differed in tens of bud shell mass. The analysis of variance provides an overall representation of the G x E interaction effects present in the experiment.
HERITABILITY TRIAL
Each progeny replicate was sampled at the same time as the adjacent replicate of the calibration set to minimize temporal differences. Examining residual plots is an important aspect of analysis to check for non-linear trends in the data, as well as other problems such as unequal variances. The differences between the spectra were small compared to the strength of the background signal caused by the solvents.
These differences were of the same magnitude as differences between spectra read repeatedly on the same sample. Further examination of the samples using HPLC showed that the chemical profiles between genotypes differed. Samples containing all possible moisture contents associated with the full spectrum of the characteristic under investigation must be included in the calibration to resolve the problem.
This assumption was proven incorrect with the acquisition of the new NIRS instrument, as there were no such differences between sample groups apparent on the new instrument. Part of the reason for this study was to expand the number of samples available. Application of near-infrared reflectance (NIR) spectroscopy in the analysis of sugarcane in clonal evaluation trials.
The role of cultivar resistance in the control of the sugarcane borer, Diatraea saccharalis (Lepidoptera: pyralidae) in Louisiana. Observations on yield damage and larval populations of the pyralid borer Eldana saccharina in sugarcane cultivars NC0376 and NIL Proc. Investigation of the performance of an improved calibration for protein detenination in UK native wheat using near-infrared reflectance analysis.
Physiological and biochemical aspects of the interaction between sugarcane and the larval Eldana saccharina Walker (Lepidoptera: Pyralidae). Distribution of genotype- and environment-related errors when predicting water-soluble carbohydrate concentration of perennial rye cultivars using near-infrared reflectance spectroscopy. Estimation of the fatty acid composition of oil in intact canola (Brassica napus L.) seed by near-infrared reflectance spectroscopy.
A preliminary assessment of the effects of different constant temperatures on the reproduction of Eldana saccharina (Lepidoptera: pyralidae). List of the 60 sugarcane cultivars used for the standard sample set for NIRS instrument calibration, including their eldana ratings (1-resistant.. 9-susceptible) and.
