Biometrical Characters Research Articles

New data on the origin of Nesiotites (Soricidae, Mammalia) in Menorca (Balearic Islands, Spain)

The presence of the shrew Nesiotites in Menorca is not yet adequately explained. Some authors consider that its ancestor arrived during the Messinian Salinity Crisis, as happened in Mallorca. Other authors consider that fossil populations in Menorca are the result of a later migration from Mallorca. In this work, several biometrical and morphological characters of abundant fossil populations from both islands have been studied. The results indicate that Early Pleistocene populations in Mallorca and Menorca are rather indistinguishable. Therefore, an early post-Messinian (Pliocene) isolation of Nesiotites in both islands is quite unlikely.

Determination of cultural and biometrical characters of Fusarium species isolated from plant material harvested from coffee (coffea canephora Pierre.) infected with CWD in Democratic Republic of Congo

The Coffee Wilt Disease (CWD) is vascular disease due to Gibberella (Fusarium) xylarioides has decimated coffee plantations in the Democratic Republic of Congo. The authors determined the characters of different species of Fusariumisolated from Robusta coffee trees affected by this disease, to establish their causality. The cultural and biometricals characters have been studied. Differences were observed between the stock of F. xylarioides and those of Fusarium lateritium, Fusarium solani, F. falciforme, and, Fusarium stilboides. Key words: CWD, Robusta coffee, Fusarium xylarioides, Fusarium lateritium,Fusarium solani, Fusarium falciforme, Fusarium stilboides.

Statistical Models for Stability Analysis in Watermelon

Fourteen promising F1 hybrids of watermelon namely IIHR-188 X IIHR-118, IIHR 114 X IIHR 118 , IIHR 119 X IIHR- 20-1, Arka Manik X IIHR 46, IIHR 43 X IIHR 46, Arka Manik X IIHR-188, Arka Jyothi, NS-295, Kushboo, Madhubala, Apoorva, CWH-7 and Riya were evaluated in experimental plots of Division of Vegetable Crops, Indian Institute of Horticultural Research, Bangalore during 2002-04. Information about biometrical characters such as fruit length (cm), fruit girth (cm), days to first male flower opening&female flower opening, rind thickness(cm) and TSS (%) along with yield (t ha-1), were used to develop stability models to identify stable hybrid(s) for a wide range for cultivation. Stability models thus developed indicated that two hybrids, viz., Arka Jyothi (with yield potential of 75.91 t ha-1) across the years and NS-295 (64.25 t ha-1) were stable for a wide range for cultivation. Statistical measures of stability, viz., regression coefficient, deviation from regression co-efficient and ecovalence measures, were worked out and utilized for grouping of hybrids into different categories based on their cumulative performance over the years.

Allozyme and morphology evolution in European Viviparidae (Mollusca: Gastropoda: Architaenioglossa)

The paper describes morphometric and allozymic differences among four European species of the family Viviparidae: Viviparus contectus (Millet, 1813), V. viviparus (Linnaeus, 1758), V. acerosus Bourguignat, 1862, and V. ater (Cristofori et Jan, 1832). Fourteen continuous biometrical characters were measured. Incremental discriminant-function analysis, principal-component analysis, and non-metric multidimensional scaling were applied to analysis of the morphometric differences. All the techniques confirmed a similar picture: a slight morphometric differentiation, with the variability ranges of the species overlapping. On the other hand, the allozymic differentiation, studied at 12 loci, eight of them intra and/or interspecific polymorphic, is much better marked, the intraspecific Nei's distances among the four V. contectus populations ranging from 0.0014 to 0.0397, mean 0.0166, and interspecific distances ranging from 0.2306 (V. ater–V. acerosus) to 0.9888 (V. contectus 2 and V. viviparus), mean 0.6871. The allele frequencies and genetic distances (Nei's distance and Cavalli-Sforza and Edwards’chord distance) were used to compute maximum likelihood, additive Fitch–Margoliash and ultrametric Fitch–Margoliash trees. All the trees presented a similar pattern, but the maximum-likelihood and additive trees, based on Cavalli-Sforza and Edwards’distance, seem to reflect the phylogeny best. The results are compared with the most parsimonious phylogenies inferred for radular, soft-part morphology and anatomy, and opercular data from other papers by us, and the inferred phylogenies are also compared. Although the inferred molecular and morphological phylogenies are little different in topology, the amount of evolution along the corresponding branches (measured as the number of changes averaged over all reconstructions) is very different, the value of correlation coefficient between the two phylogenies being statistically insignificant. The occurrence of interspecific hybrids is discussed, and the isolation-by-competition mechanism is postulated. The probable origin of V. viviparus from a founder population extremely restricted in number is stressed. The possible history of the group is briefly discussed. The species is suggested to have originated in an unusual habitat of melt water at a glacier foreland that could have promoted genotypic differentiation and sympatric speciation.

Morphological and allozymic variation within and between populations of Bythinella Moquin-Tandon, 1855 (Gastropoda: Prosobranchia). I. Morphological characters

Morphology and anatomy of 20 Central European populations of the spring snail Bythinella Moquin-Tandon are described and illustrated. Detailed descriptions, drawings and SEM photographs, as well as measurements of shells, opercula, radulae and soft parts are presented, special attention being paid to the reproductive organs. Intrapopulation and interpopulation differences in 40 biometrical characters in males and 42 in females are analysed, for each sex separately, by means of descriptive statistics and ANOVA. Relations between variables are tested with Kendall’s correlation coefficient. Biometrical characters vary widely within and slightly between the studied populations, whose variability ranges overlap. The length ratios: shell/radula, bursa/bursa duct and bursa/receptacle, as well as the length of bursa copulatrix and ctenidium display a statistically significant S-N clinal variation. The wide intrapopulation variation combined with the slight differences between the distinguished morphospecies in almost all the morphological characters examined indicates a limited diagnostic value of these characters in Bythinella.

Discriminant analysis of selected yield components and fatty acid composition of chosen Triticum monococcum, Triticum dicoccum and Triticum spelta accessions

This study analyses the variability of key yield components, the content of protein and crude fat in grain and the fatty acid composition of 50 spring accessions of Triticum monococcum, Triticum dicoccum and Triticum spelta of various origins. The average protein content of the grain of T. monococcum was 20.8%, of T. dicoccum 19.7%, and of spelt 17.0%. The crude fat content of T. monococcum grain (2.7%) was significantly higher compared with T. spelta (2.4%) and T. dicoccum (2.3%). In crude fat, fatty acids C18:2, C18:1 and C16 predominated. T. spelta was characterised by the highest concentrations of C18:2 and C16 (55.89% and 18.77% respectively), while T. monococcum had the highest content of C18:1 (26.35%). The structure of analysed fatty acids proved to be highly desirable in this species. A discriminant analysis performed separately for five variables: protein and fat content and three biometrical characters and separately for fatty acid composition enabled three Triticum species to be distinguished. These species also differed significantly with respect to the C18:1/C16 ratio which was equal to 1.78, 1.06, 1.47 and 0.99 in T. monococcum, T. dicoccum, T. spelta and Triticum aestivum respectively.

Morphological Relationships Between Polyploid Hybrid Spined Loaches of the GenusCobitis(Teleostei: Cobitidae) and their Parental Species

A special feature of spined loaches of the genus Cobitis in Central Europe is the frequent occurrence of diploid-polyploid complexes in which polyploid gynogenetic forms act as sperm parasites to the diploid form. This tight binding of the co-occurring forms results in a high level of phenotypic and ecological similarities. The present study searches for morphological differences between them applying the characters traditionally used in loach taxonomy (body proportions, fin formula, scale shape, lamina circularis, suborbital spine, coloration) in 662 specimens from the Baltic (14 populations) and North Sea (1 population) catchment areas. Ploidy level of each specimen was inferred from blood cell measurements. Discriminant function analysis for biometrical characters and description of qualitative features indicate the morphological distinctness of the two diploid species C. taenia and C. elongatoides. The polyploid unisexual biotypes are very similar to each other and to individuals of sympatric sexual species. The genome dosage effect could be observed in morphological characters, however, in some of them the polyploid biotypes display a mosaic mode of variability: they can be more similar to sympatric parents or to the absent species in the complex, transitional and of a wider variability range. In colouration pattern, the biotypes do not express the whole spectrum of the parental species variability. Meristic traits had no power to identify the different forms.

A goal programming approach for developing pre-harvest forecasts of crop yield

In this paper, an attempt has been made to develop a pre-harvest forecast of sugarcane yield. The forecast is based on plant biometrical characteristics such as plant height, girth of cane, number of canes per plot and width of third leaf from the top. Some of these characteristics are correlated and hence the conventional practice of fitting a regression model using least square technique for estimating the parameters does not lead to satisfactory pre-harvest forecasts. Keeping in view the difficulties relating to the violation of the assumptions of normality, independence and homoscedasticity of classical multivariate regression analysis, the present study proposes an alternative approach, which is free from assumptions. It employs a goal programming formulation to estimate the pre-harvest yield of sugarcane on the basis of measurements on biometrical characters of the plant. In order to assess the quality of forecasts, variance of residuals obtained from the proposed method has been compared with that obtained from the conventional regression analysis. The study reveals that there is no significant difference (P-value=0.43461) in the variances of the two residual series. Thus, without compromising the quality of forecast, the proposed alternative methodology can be adopted to estimate the sugarcane yield 3 months before harvest in situations, where the assumptions of conventional regression analysis are violated.

Cepaea vindobonensis (Férussac,1821) in the Pieniny Mts

Cepaea vindobonensis (Férussac,1821) in the Pieniny Mts

Path Analysis Technique to assess the relationship of wheat yield with its components under Agroforestry system

The method of ‘path coefficients’ has been used for analyzing correlation coefficients between yield of Wheat and its other biometrical characters under four different tree species. This technique helps in establishing the relative importance of various biometrical characters of Wheat, viz. plant population, plant height, number of tillers per plant, grain weight per earhead, and number of effective tillers as determiners of Wheat yield under different species of fruit trees in agroforestry system.

A correlation and path coefficient analysis of wheat components under multipurpose tree species

The method of ‘path coefficients’ has been used for analyzing correlation coefficients between yield of Wheat and its other biometrical characters under four different tree species. This technique helps in establishing the relative importance of various biometrical characters of Wheat, viz. plant population, plant height, number of tillers per plant, grain weight per earhead, and number of effective tillers as determiners of Wheat yield under different Multipurpose Tree Species (MPTs) in agroforestry system. It is observed from the correlation components that number of tillers and number of effective tillers exerted a greatest influence both directly and indirectly upon the yield of Wheat crop under all the four tree species.

Use of Growth Indices in Markov Chain Models for Crop Yield Forecasting

An improved Markov chain model has been developed for forecasting of sugarcane yields in which growth indices of biometrical characters based on data from two stages simultaneously have been utilised. Comparisons were also made with the models in use viz. the regression model and the first order Markov chain model.

Use of Growth Indices in Markov Chain Models for Crop Yield Forecasting

An improved Markov chain model has been developed for forecasting of sugarcane yields in which growth indices of biometrical characters based on data from two stages simultaneously have been utilised. Comparisons were also made with the models in use viz. the regression model and the first order Markov chain model.

Biometry and DNA fingerprinting detect limited genetic differentiation among populations of the apomictic blackberry Rubus nessensis (Rosaceae)

Clonal plant species have in many recent studies exhibited unexpectedly high levels of genetic differentiation. This seems to hold true also for several apomictic (agamospermous) species in spite of their potential ability to spread single genotypes over large areas through seed dispersal. By contrast, previous DNA fingerprint studies have demonstrated apomictic Rubus species to be extremely homogeneous. The present study was undertaken to estimate the extent and distribution of intraspecific genetic variation in R. nessensis. Populations differed significantly for many biometrical characters but this variation was evenly distributed, with few significant differences between single pairs of populations. Patterns indicating ecoclinal variation, which could be adaptive in origin, were not found. Populations also clustered close together in a two-dimensional CVA plot, with only one population being somewhat further removed. DNA analysis of later collected material from this population as well as from three others yielded identical DNA fingerprints with each of two different multi-locus DNA probes. Taken together with previous DNA fingerprint studies, these results indicate that a major part of the R. nessensis plants in Northern Europe have been derived from a single recombinational event, possibly making this genet the most widespread land-living organism in the world. The encountered variation in biometrical characters is probably instead caused by e.g. minor somatic mutations. Rubus species have relatively large, bird-dispersed seeds that probably travel further than the small, wind-dispersed seeds found in most previously investigated apomicts (e.g. in Asteraceae). The potential for single genotypes to disperse over large areas should therefore be greater in Rubus than in many other apomictic species groups.

Effects of formaldehyde preservation on biometrical characters, biomass and biochemical composition ofAcartia clausi (Copepoda, Calanoida)

The effects of formaldehyde preservation on biometrical characters, biomass and biochemical composition of the marine copepodAcartia clausi were studied using the relevant values of fresh unpreserved animals as reference.Acartia were collected in the southern parts of Saronicos Gulf in early May (16.5°C) and late June (21°C). Formalin was found to cause significant shrinkage of cephalothorax length, abdomen length and total length. The sex of individuals, as well as the temperature of seawater at the time of collection seem to influence dimensional losses. Females and animals collected at 16.5°C presented heavier losses. Dry weight is drastically reduced after formaldehyde preservation. Final losses are more severe for females and animals collected at 21°C. Two of the measured biochemical constituents, carbohydrates and neutral lipids, seem to be unaffected by formaldehyde. DNA and RNA although initially affected seem to be stabilized towards the end of the experimental period (30 days). The other biochemical parameters, viz proteins, total lipids and sugars, are profoundly affected by preservation.

Diagnostic Characters and Distribution of Meriones Illiger, 1811 Species (Mammalia: Rodentia) in Turkey

In this study, specimens of Meriones collected from various areas of Turkey were evaluated based on morphological and biometrical characters. It was determined that four species; Meriones tristrami, Meriones vinogradovi, Meriones meridianus and Meriones crassus exist in Turkey. External characters such as the terminal tuft on tail, the colour of ventral hairs, the soles of hind foot and the length of tail, and cranial characters such as the structure of suprameatal triangle, the connection of anterior rim of auditory meatus to squomosal and the projection of mastoid portion of tympanic bullae from supraoccipitals were determined to be useful in distinguishing species of Meriones. The range of M. tristrami in steppes and plains below altitude of 1200 m in Anatolia, M. vinogradovi in vicinity of Kars and Iğdır province, M. meridianus at sandy belts in the north of Ağrı mountain and M. crassus in Southeastern Anatolia were determined.

Use of spectral data in Markov chain model for crop yield forecasting

Crop yield is mainly dependent on weather, soil and technological inputs. Yield forecasting models have been developed mainly using multiple regression techniques based on biometrical characters of the plants and/or weather parameters. Matiset al. (1985) proposed another approach of crop yield modelling using Markov Chain theory based on biometrical characters. The integration of remote sensing with other technologies has provided an immense scope to improve upon the existing crop yield models. In the present study, multi date spectral data during crop growth period was used in Markov Chain Model to forecast wheat yield. The results indicate that the use of spectral data near the maximum vegetative growth of wheat crop improves the efficiency and reliability of yield forecast about a month before its actual harvest.

Jonopsidium savianum (Caruel) Ball ex Arc. (Cruciferae): phytosociological, pedological, biometrical and karyological analyses

Summary Phytosociological, pedological, biometrical and karyological analyses were carried out on Jonopsidium savianum (Caruel) Ball ex Arc. (Cruciferae), a rare Italian species whose present distribution is discontinuous. Indeed, this species can be found oiily at three stations in Tuscany, in the phytoclimatic belt of Lauretum and at a few others in Umbria and Latium, in the phytoclimatic belt of Fagetum. The phytosociological surveys showed an essential homogeneity both within the group of Tuscan stations and within the group of those in Umbria and Latium. On the contrary, the vegetation differs clearly when the two groups of stations are compared. Several pedological traits and certain quantitative characters of the plants differ significantly between the stations. However, no significant differences in biometrical characters were found when plants obtained from seeds collected at different stations were grown together in the same environment. Populations do not differ as far as the number and gross structure of the chromosomes are concerned, except for supernumerary chromosomes, which are present in all the populations, but they increase in number in some of the populations, in relationship to features of the soils.

Multivariate analysis of the Vicia sativa L. aggregate

The sativa group of species was studied by using multivariate analysis and karyological analysis. Thirty biometrical characters were studied by using 92 Vicia sativa L. accessions from a variety of geographical sources. The four main taxa analysed were: sativa, macrocarpa, cordata and angustifolia. Principal component analysis provided clear separation among sativa, cordata and angustifolia in terms of the first two components. Karyotype analysis confirmed the PCA results, and by combining both methods, misclassed specimens can be correctly determined. Cluster analyses using the characters which displayed the greatest loads over the first components were performed in order to identify the most valuable characters from the taxonomic point of view. These were flower length, calyx length, pod width, constriction of the pod between seeds, leaf length, leaflet width, seed length and seed width. Our results suggest an early separation of angustifolia from the ancestral stem. The taxon cordata may be useful in future plant breeding programmes not only for crossing with V. sativa to increase the leaflet size of this taxon, but also as a bridge species between sativa and angustifolia.

Multivariate Analysis of the Vicia sativa L. aggregate

The sativa group of species was studied by using multivariate analysis and karyological analysis. Thirty biometrical characters were studied by using 92 Vicia sativa L. accessions from a variety of geographical sources. The four main taxa analysed were: sativa, macrocarpa, cordata and angustifolia. Principal component analysis provided clear separation among sativa, cordata and angustifolia in terms of the first two components. Karyotype analysis confirmed the PCA results, and by combining both methods, misclassed specimens can be correctly determined. Cluster analyses using the characters which displayed the greatest loads over the first components were performed in order to identify the most valuable characters from the taxonomic point of view. These were flower length, calyx length, pod width, constriction of the pod between seeds, leaf length, leaflet width, seed length and seed width. Our results suggest an early separation of angustifolia from the ancestral stem. The taxon cordata may be useful in future plant breeding programmes not only for crossing with V. sativa to increase the leaflet size of this taxon, but also as a bridge species between sativa and angustifolia.