Hereditary correlation of size and color characteristics in tomatoes

From the hereditary standpoint, color and size characters in either plants or animals are not equally well understood. In general, the inheritance of color, technically known as a qualitative character, has been rather satisfactorily determined. On the modern chromosome theory of heredity, the genetic factors responsible for the development of colors appear to be located on the various chromosomes of the species and apparently follow a regular, stable and predictable mode of inheritance from generation to generation. Environmental agencies play a relatively minor part in ;modifying such characters. It is for this reason, perhaps, that their inheritance has been so thoroly investigated

Genetic tests for linkage between row number genes and certain qualitative genes in maize

Tests on a large scale were devised to determine if the multiple genes for kernel row number on the maize ear would show genetic linkage with known genes on several of the maize chromosomes. The linkage groups tested involved P (pericarp and cob), R (aleurone), Su, (endosperm), and Y (endosperm color) chromosomes. A very significant correlation between cob (and pericarp) color and row number was discovered in a large series of crosses. This was so pronounced that one is inclined very strongly to believe that one of the major row-number genes is located on the P chromosome. The experiments involving aleurone color (C and R factors) and row number gave some evidence of a correlation. This was particularly true when the R-aleurone factor was involved with row number. The correlation or linkage was intangible in some crosses, and yet the bulk of the data pointed to the probability that a row number gene was also to be found on the R-chromosome. When the Su-chromosome was tested for the existence of still another row-number gene, a variable lot of data appeared. Certain crosses exhibited all the phenomena of genetic linkage between this endosperm character and row number; and yet there were enough exceptions to cast doubt on the existence of such a simple relationship as an ordinary linkage. In fact several cases of distinct reversal of linkage (parental classes occurring less frequently than non-parental) were noted, a situation which would seem to necessitate a reinvestigation of this problem. Some evidence of a genetic linkage between the Yy endosperm color and row number was obtained. It was significantly present in the majority of the hybrid generations. The intensity of this linkage, however, must be relatively low. In general, one may deduce from a large series of experiments such as these that the inheritance of row number is relatively complex, that the phenotype of row number is not always an indication of its true genotype even aside from environmental influence, and that the detection of genes for row number on the various chromosomes of maize is exceedingly difficult

Inheritance of Fruit Shapes and Sizes in the Pepper and Tomato

Both Capsicum and Lycopersicum exhibit the same correlation between fruit shape and fruit size, a correlation which is wholly lacking for the same characters in the Cucurbits. In the pepper both positive and negative correlations of shape and size were discovered in F2 generations, the sign of the correlation being dependent on the parental combinations. Accordingly the cause for the correlations must be the genetic one of linkage, due to the presence of shape and size genes on the same chromosome, a fact which has already been reported for the tomato. Fruit sizes in both genera exhibit logarithmic rather than additive distributions

Genetic Stability of Tomato Diploids and Tetraploids Derived from Haploid

By doubling the chromosomes of a haploid tomato asexually (decapitation-callus technique) an absolutely homozygous diploid is produced. Ten generations of severe selection to break this pure line have resulted only in very minor changes, easily attributable to a normal mutation rate. Data on the effect of the selection pressure on dry weight of plants and on size and weight of fruits show no statistically significant effects in two selection lines and a barely significant ( 5 per cent point) effect in a third selection line. Only one major point-mutation was noted among the 12,000 experimental plants (a mutation to a recessive wiry form, different genetically from the original wiry mutant) and this occurred in the control lines. These results are directly opposed to the Russian worker, Lysenko\u27s claims that the tomato deteriorates in three to five generations. The original haploid, now carried on asexually for 12 years, has proved also to be remarkably stable, only one large bud-sport having been observed

Fruit Size and Shape Genes on the First Chromosome of the Tomato

Genetic evidence has demonstrated the presence of a major factor for fruit size in the first linkage group of the tomato, linked inheritance being exhibited between fruit size and the genes for the tall-dwarf and the smooth-peach (pubescent) characters. In this same linkage group a major gene for fruit shape (ovate) has been found

Inheritance of Shape in Tomato Fruits

Ovate fruit is determined by a major recessive gene located in the first chromosome of the tomato. It is allelomorphic to both the round and the oblate types. These in turn are differentiated by a main factor and are allelomorphic to each other. This suggests a multiple allelomorphic series of genes controlling the oblate, round and ovate fruit shapes. Ovate shape (when contrasted with oblate) shows linked inheritance with dwarf growth habit, there being approximately ten or eleven per cent crossing over. There is also close linkage between ovate shape and the peach character of the fruit. High positive correlation exists between fruit shape (measured quantitatively by means of polar and equatorial diameter measurements) and fruit size, suggesting a linkage between shape factors and size factors on the first chromosome

Linear Order of Four Genes on the First Chromosome of the Tomato

Genetic tests for linkage have shown that four pairs of hereditary factors belong on the first chromosome of the tomato. They are: 1. Tall - dwarf growth habit. Genes Dd. 2. Smooth- peach (pubescent) fruit. Genes Pp. 3. Oblate (or round) - ovate fruit shape. Major genes Oo. 4. Simple- compound flower cluster. Genes Ss

Optimization of resource allocation can explain the temporal dynamics and honesty of sexual signals

In species in which males are free to dynamically alter their allocation to sexual signaling over the breeding season, the optimal investment in signaling should depend on both a male’s state and the level of competition he faces at any given time. We developed a dynamic optimization model within a game‐theoretical framework to explore the resulting signaling dynamics at both individual and population levels and tested two key model predictions with empirical data on three‐spined stickleback (Gasterosteus aculeatus) males subjected to dietary manipulation (carotenoid availability): (1) fish in better nutritional condition should be able to maintain their signal for longer over the breeding season, resulting in an increasingly positive correlation between nutritional status and signal (i.e., increasing signal honesty), and (2) female preference for more ornamented males should thus increase over the breeding season. Both predictions were supported by the experimental data. Our model shows how such patterns can emerge from the optimization of resource allocation to signaling in a competitive situation. The key determinants of the honesty and dynamics of sexual signaling are the condition dependency of male survival, the initial frequency distribution of nutritional condition in the male population, and the cost of signaling

Geochemistry and petrology of a suite of ten Yamato HED meteorites

We have performed petrological characterization and geochemical studies by instrumental neutron activation analysis of a suite of ten Yamato HED samples : Y-74013,Y-74097 and Y-74136 (Type A diogenites); Y-75032 and Y-791199 (Type B diogenites); Y-791195 (cumulate eucrite); Y-793164 and Y-82066 (eucrites); and Y-791192 and Y-82049 (polymict eucrites). The Type A diogenites are essentially identical in composition except for slight differences in Cr, Co, Se and La, which are likely due to inhomogeneous distribution of the minor phases chromite, metal and troilite, and trapped interstitial melt, respectively. The petrology and REE patterns for Type B diogenites show that they are not adcumulate rocks, but rather, contain substantial, perhaps 15%, interstitial liquid trapped in the samples. Y-791195 is a cumulate eucrite intermediate in REE content between Serra de Mage and Moore County, but is more ferroan. Eucrite Y-82066 is similar in composition to trace element-poor main-group eucrites such as Sioux County, and may be a primitive partial melt of the HED parent body. Y-793164 is intermediate in composition between main-group eucrites and Nuevo Laredo in Fe, Cr, Sc and REE, and is an intermediate member of the Nuevo Laredo trend eucrites. Y-793164 is a residual liquid from perhaps 25-30% crystallization of a primitive main-group eucrite like Sioux County or Y-82066. Y-791192 and Y-82049 are classified as polymict eucrites, but major and trace element concentrations indicate that these meteorites contain about 36% and 48% diogenitic material, respectively. These samples are howardites based on our analyses. Y-82049 contains a wide range of pyroxene compositions, from magnesian orthopyroxene similar to Type A diogenite pyroxenes, to ferroan pigeonite similar to basaltic eucrite pyroxenes. Large pyroxene clasts in Y-791192 are dominantly similar to Type B diogenite pyroxenes