Genetic Variation In Morphology Research Articles

Morphological Variation of Limnonectes blythii in West Sumatera, Indonesia

Abstract:
 This study aimed to analyze the morphological variations of Limnonectes blythii in West Sumatra by using morphometric in Genetics and Cytology Laboratory, Department of Biology, Faculty of Mathematics and Natural Sciences, Andalas University, Padang. The sample of this research was collected directly in West Pasaman (Nature Reserves Malampah), Sijunjung (Nature Reserve Pangean) and Payakumbuh (Harau Nature Reserve) in February until Mai 2015. The results showed that there is genetic variation in morphology of the population L. blythii in Malampah and Pangean as the first cluster with a population in Harau. The kinship between populations in Pangean and Malampah as the second cluster is closer to the population at second subcluster with Harau population and have the more distant kinship of the population L. blythii in Pangean. It was concluded that 12 morphological characters show differentiation significant (p≥ 0005) of the population, while the population of Harau and Sijunjung showed significant differentiation as many as 10 characters (32.2%), Between population differentiation Harau with Malampah show as much as 8 characters (25.8% ), and between population Malampah with Sijunjung show 7 (22:58%) differentiated character. This study requires molecular analysis to clarify the phylogenetic relationships among L. blythii to preserve the information of this frog as an export commodity.

Quantitative Morphological Variation in the Developing Drosophila Wing.

Quantitative genetic variation in morphology is pervasive in all species and is the basis for the evolution of differences among species. The measurement of morphological form in adults is now beginning to be combined with comparable measurements of form during development. Here we compare the shape of the developing wing to its adult form in a holometabolous insect, Drosophila melanogaster. We used protein expression patterns to measure shape in the developing precursors of the final adult wing. Three developmental stages were studied: late larval third instar, post-pupariation and in the adult fly. We studied wild-type animals in addition to mutants of two genes (shf and ds) that have known effects on adult wing shape and size. Despite experimental noise related to the difficulty of comparing developing structures, we found consistent differences in wing shape and size at each developmental stage between genotypes. Quantitative comparisons of variation arising at different developmental stages with the variation in the final structure enable us to determine when variation arises, and to generate hypotheses about the causes of that variation. In addition we provide linear rules allowing us to link wing morphology in the larva, with wing morphology in the pupa. Our approach provides a framework to analyze quantitative morphological variation in the developing fly wing. This framework should help to characterize the natural variation of the larval and pupal wing shape, and to measure the contribution of the processes occurring during these developmental stages to the natural variation in adult wing morphology.

Genetic Variation in Morphology, Seed Quality and Self-(in)Compatibility among the Inbred Lines Developed from a Population Variety in Outcrossing Yellow Mustard (Sinapis alba).

Yellow mustard (Sinapis alba L.) has been grown as an important source of condiment for the spice trade in the world. It is an obligate outcrossing species due to its sporophytic self-incompatibility (SI). To utilize heterosis for yield potential, we have attempted to develop elite component inbred lines for producing high-yielding synthetic varieties for this crop. The open-pollinated variety Andante was used as the initial population. To circumvent the SI barrier, bud-pollination for selfing was performed on the selected initial (S0) plants. Various types of inbreeding depression were observed in the S1 generation. Elite inbred lines tolerant to inbreeding were produced by purging the deleterious alleles in each inbred generation. Self-compatible (SC) lines were developed for the first time in this species. There were three types of erucic variants (high: 49.9%, median: 23.9% and low: 1.4%), three types of linolenic variants (high: 18.5%, median: 13.8% and low: 3.8%) and two types of mucliage variants (high: 164.0 cS*mL/g and low: 12.0 cS*mL/g) among the developed inbred lines. These variants are being used to investigate the genetic and molecular mechanism underpinning the phenotypic variation of the seed oil profile and SI/SC traits in yellow mustard.

Genetic Variation in Morphology and Growth Characters of Acacia koa in the Hawaiian Islands

Substantial phenotypic variation in Acacia koa has been reported in the Hawaiian Islands. We grew 72 A. koa families from the islands of O`ahu, Kaua`i, and Hawai`i in two common gardens to determine whether phenotypic differences in phyllode morphology, extrafloral nectary morphology, and other characters have a genetic basis. Significant differences among islands and families were observed for phyllode width, curvature, and pubescence, as well as extrafloral nectary size and pigmentation, retention of juvenile leaves, and branch bark color. Seed shape also differed significantly among islands. Discriminant analysis revealed that families from the island of Hawai`i are distinct from O`ahu and Kaua`i families. The O`ahu and Kaua`i families, however, could not be reliably distinguished based on sapling morphology or growth characters.

GENETIC DIVERGENCE IN BODY SIZE AMONG EXPERIMENTAL POPULATIONS OF DROSOPHILA PSEUDOOBSCURA KEPT AT DIFFERENT TEMPERATURES.

The body dimensions of many animals vary in a regular way with environmental temperature, and the several ecogeographical have been formulated to describe these situations (see Mayr, 1963, for a review). The rules are most often discussed for homeotherms, since a possible connection with conservation of body heat arises, but many organisms with no internal regulation of body temperature vary in a similar way (Ray, 1960; Lindsey, 1966). The morphological variation may be simply a phenotypic response to temperature, reflecting developmental plasticity, or it may be partly or wholly genetic. Genetic differences in morphology are established from comparisons among geographic strains reared under the same, or nearly the same, conditions. The probable role of selection in producing the genetic differences is inferred from a correlation of genetic variation in morphology with environmental variation in temperature. Particularly for poikilotherms such as insects, a physiological basis for selection by environmental temperature or its correlates is often not apparent. Genetic variation in morphology, as measured by such characters as wing and thorax length, has been recorded for four Drosophila species. Stalker and Carson (1947) found that wing length in D. robusta decreased with mean annual temperature of the localities at which collections were taken, while thorax length varied in the opposite direction. Prevosti (1955) and Misra and Reeve (1964) showed a decrease in both wing length and thorax length with mean annual temperature for populations of D. subobscura. Tantawy and Mallah (1961) found that wing length and thorax length were higher in strains of D. melanogaster from cooler areas within the Middle East. Wing length is an excellent index of body size in D. pseudoobscura (Sokoloff, 1966); although it varies among populations, there is no correlation with latitude or mean annual temperature (Sokoloff, 1965; Anderson, 1968). In nature, of course, temperature is only one of many factors which influence selection for body size, and the confounding effects of other selective factors may obscure the individual effect of temperature. That discernible clines exist at all is a clear indication of the importance of temperature. Laboratory populations maintained at different temperatures provide a means of assessing the selective effects of temperature on body size with less complication from other environmental factors. Anderson (1966) studied experimental populations of D. pseudoobscura which were kept for six years at 16, 25, and 27 C, two replicate populations being maintained at each temperature. After one and a half years there was no evidence for divergence in body size, as measured by wing length, but at six years a striking divergence was evident, the populations kept at 16 C having become genetically determined for much larger size than those kept at 25 and 27 C. Temperature was clearly a major environmental difference among these populations, and the similarity of results for the replicate populations at each temperature argues against a chance divergence to larger size at the lower temperature and smaller size at the higher temperatures. Thus the morphological divergence among the experimental populations could well result from a selection similar to that which acts in