We provide a comprehensive SAS program for the computation of univariate and multivariate stability statistics for balanced data. The program is intended for genotype × location × year (G × L × Y) or genotype × location (G × L) data, averaged over replications (R). It computes the symmetrical joint linear regression with the right and left solutions and Tukey's 1 df for nonadditivity, the regression coefficients (b‐ or β‐values), and the deviations from regression (δij) and provides the graphs of the regression lines for both genotypes and locations. Separate regression on the positive and negative sectors of the environmental indices is also conducted. The program calculates Tai's α and λ statistics with graphical presentation of the scatter of the genotypes in the α, λ space. Other outputs of the program include the univariate stability statistics Wricke's ecovalence (Wi2), Shukla's stability variance (σi2), Hanson's genotypic stability (Di2), Plaisted and Peterson's θi, Plaisted's θ(i), Francis and Kannenberg's environmental variance (Si2), and coefficient of variance (CV); and the rank‐based nonparametric stability statistics Si(2), Si(3), Si(6), Kang's rank sum, and the stratified rank analysis of the genotypes. The program also computes Type 4 stability, superiority measure (Pi), the desirability index of genotype performance, and the pairwise genotype × environment (G × E) interaction of genotypes with checks. It partitions the G × E interaction into that due to heterogeneity of variances and that due to imperfect correlation between the genotype performance and performs the singular value decomposition of the G × E matrix, plotting the first two interactions’ principal components.

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An infra-red investigation has been made of gas-phase hydrogen bonding between a range of amines and alcohols. Frequency displacements of the 0-H stretching vibration have been obtained for some thirty gas-phase hydrogen bonded complexes. These displacements for a se.ries of amines provide a measure of the relative electron donating abilities of the free arnineS : Et3N> Et2NHmMe3N > Me2NH > EtNHa > MeNH2 > NH3. Band contours for the 0-H stretching mode of such gas-phase complexes are reported and discussed. These can be interpreted in terms of sum-and-difference bands of the 0-H stretching vibration and the hydrogen bond stretching vibration. The interpretation can account for the qualitative changes in band contour that occur along a series of complexes. The systems considered include those formed by ammonia, methylamine, dimethy lamine, trimethylamine, ethylamine and diethy lamine with methanol, ethanol, isopropanol, t-butanol, and trifluoroethanol. Some complexes of triethylamine are also included. ' B. C. Stace and J. A. Stratford, to be published.

DNA-based RAPD (Random Amplification of Polymorphic DNA) markers have been used extensively to study genetic diversity and relationships in a number of fruit crops. In this study, 10 (7 commercial mango cultivars and 3 accessions) mango genotypes traditionally grown in Suez Canal and Sinai region of Egypt, were selected to assess genetic diversity and relatedness. Total genomic DNA was extracted and subjected to RAPD analysis using 30 arbitrary 10-mer primers. Of these, eleven primers were selected which gave 92 clear and bright fragments. A total of 72 polymorphic RAPD bands were detected out of 92 bands, generating 78% polymorphisms. The mean PIC values scores for all loci were of 0.85. This reflects a high level of discriminatory power of a marker and most of these primers produced unique band pattern for each cultivar. A dendrogram based on Nei's Genetic distance co-efficient implied a moderate degree of genetic diversity among the cultivars used for experimentation, with some differences. The hybrid which had derived from cultivar as female parent was placed together. In the cluster, the cultivars and accessions formed separate groups according to bearing habit and type of embryo and the members in each group were very closely linked. Cluster analysis clearly showed two main groups, the first consisting of indigenous to the Delta of Egypt cultivars and the second consisting of indigenous to the Suez Canal and Sinai region. From the analysis of results, it appears the majority of mango cultivars originated from a local mango genepool and were domesticated later. The results indicated the potential of RAPD markers for the identification and management of mango germplasm for breeding purposes.

An infrared investigation has been made of relatively weak hydrogen bonded complexes in the gas phase. Wavenumbers and band contours for hydrogen stretching modes have been investigated for 0-H -* -0 complexes formed by methanol, ethanol, propan-2-01 and 2-methylpropan-2-01 with some simple ethers, and also with tetrahydrofuran and 1,4-dioxan. The wavenumber displacements provide a measure of the electron donating abilities of the free ethers, leading to the following series according to increasing basicity : MezO w 1,4-dioxan < Et20 < THF < PriO. The bands for the 0-H stretching vibration of the alcohol+ether systems are found to be broad but with little or no structure, and this is discussed in terms of the sum-and-difference band theory of broadening.Examples of C-H ---N hydrogen bonding in the gas phase have been detected for trichloromethane + amine systems and frequency displacements are listed. The order of increasing basicity of amines as indicated by these frequency displacements is : NH3 < MeNHz < Me2N < Me3N.In Part 3,l gas-phase complexes formed by relatively strong alkyl or aryl 0-H proton donors were examined. The present paper reports the investigation of still weaker complexes. A number of 0-H --0 complexes formed between alkanols and ethers have been studied and examples of a new class of weak gas-phase complexes, namely C-H -N complexes have also been examined. EXPERIMENTALSpectra were recorded on a Unicam SPlOO infrared spectrometer using a cell of 75 cm path length. The sample procedure used has been described in Part 1.2