Complex hybridity in Isotoma petraea. IV. Heterosis in interpopulational hybrids

1974 ◽  
Vol 22 (2) ◽  
pp. 251 ◽  
Author(s):  
IC Beltran ◽  
SH James
Keyword(s):  
Discriminant Analysis ◽  
Natural Populations ◽  
Dry Weight ◽  
Base Population ◽  
The Individual ◽  
Relational Balance

Discriminant analysis of four structurally homozygous populations of Isotoma petraea showed that they are significantly different with respect to phenotypes produced in a standardized environment and hence they are genetically different. These populations are relatively homozygous for different arrays of genes and their interpopulational hybrids exhibit a euheterotic increase in aerial dry weight. The individual natural populations may be considered as depressed inbred lineages of the relationally balanced base population of I. Petraea. The degree of heterosis observed in their interpopulational hybrids is mainly influenced by the degree of inbreeding that is characteristic of of each population. Negative heterosis was observed in interpopulational crosses among complex heterozygotes. The complex heterozygotes are genetically heterozygous, and a precise relational balance exists between the complexes associated in the native complex heterozygotes; this coadaptation does not extend from population to population.

scholarly journals Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 613-620 ◽  
Author(s):  
J A McKenzie ◽  
A G Parker ◽  
J L Yen
Keyword(s):  
Resistant Strain ◽  
Single Gene ◽  
Natural Populations ◽  
Susceptible Strain ◽  
Selection Line ◽  
Base Population ◽  
Gene Response ◽  
Biochemical Profiles ◽  
Resistant Strains ◽  
Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

scholarly journals Individual growth of Heleobia piscium in natural populations (Gastropoda: Cochliopidae) from the multiple use natural Reserve Isla Martin Garcia, Buenos Aires, Argentina

2008 ◽  
Vol 68 (3) ◽  
pp. 617-621 ◽  
Author(s):  
SM. Martin
Keyword(s):  
Buenos Aires ◽  
Natural Populations ◽  
Dynamic Structure ◽  
Reproductive Period ◽  
Individual Growth ◽  
Growth Equation ◽  
Multiple Use ◽  
Natural Reserve ◽  
Drainage Channels ◽  
The Individual

The present work analyses the individual growth of Heleobia piscium in natural conditions in coastal drainage channels of the Multiple Use Natural Reserve Isla Martín García, Buenos Aires, Argentina. Isla Martín García is located in the Upper Río de la Plata, to the south of the mouth of the Uruguay river (34° 11' 25" S and 58° 15' 38" W). Monthly collections were made from July 2005 to July 2006 in the eastern part of the island (Arena Beach). The population of H. piscium showed a complex and dynamic structure of sizes during a long period of the annual cycle. Two cohorts could be detected. The Bertalanffy growth equation was: Lt = 6 (1-e -1.85 (t+0.38)) and Lt = 3.9 (1-e -0.19 (t+4.84)) for cohorts 1 and 2, respectively. The pattern of population growth displayed a staggered model, where the greatest growth is observed during the summer. The reproductive period occurred during six months, from the beginning of summer to middle of fall. Based on only one reproductive effort, this pattern is not similar to that of other cogeneric species already studied.

Identification and Classification of Fungal Colonies in Moldy Paddy Based on Computer Vision

2018 ◽  
Vol 61 (5) ◽  
pp. 1497-1504
Author(s):  
Zhenjie Wang ◽  
Ke Sun ◽  
Lihui Du ◽  
Jian Yuan ◽  
Kang Tu ◽  
...  
Keyword(s):  
Computer Vision ◽  
Discriminant Analysis ◽  
Texture Features ◽  
Fungal Species ◽  
Projection Algorithm ◽  
Support Vector ◽  
Linear Discriminant ◽  
Sequential Selection ◽  
The Individual

Abstract. In this study, computer vision was used for the identification and classification of fungi on moldy paddy. To develop a rapid and efficient method for the classification of common fungal species found in stored paddy, computer vision was used to acquire images of individual colonies of growing fungi for three consecutive days. After image processing, the color, shape, and texture features were acquired and used in a subsequent discriminant analysis. Both linear (i.e., linear discriminant analysis and partial least squares discriminant analysis) and nonlinear (i.e., random forest and support vector machine [SVM]) pattern recognition models were employed for the classification of fungal colonies, and the results were compared. The results indicate that when using all of the features for three consecutive days, the performance of the nonlinear tools was superior to that of the linear tools, especially in the case of the SVM models, which achieved an accuracy of 100% on the calibration sets and an accuracy of 93.2% to 97.6% on the prediction sets. After sequential selection of projection algorithm, ten common features were selected for building the classification models. The results showed that the SVM model achieved an overall accuracy of 95.6%, 98.3%, and 99.0% on the prediction sets on days 2, 3, and 4, respectively. This work demonstrated that computer vision with several features is suitable for the identification and classification of fungi on moldy paddy based on the form of the individual colonies at an early growth stage during paddy storage. Keywords: Classification, Computer vision, Fungal colony, Feature selection, SVM.

scholarly journals The distribution of phospholipase D in developing and mature plants

1969 ◽  
Vol 112 (5) ◽  
pp. 787-794 ◽  
Author(s):  
R. H. Quarles ◽  
R. M. C. Dawson
Keyword(s):  
Phospholipase D ◽  
Dry Weight ◽  
Total Activity ◽  
Weight Basis ◽  
Carrot Root ◽  
Aerial Parts ◽  
Central Stalk ◽  
Pea Seeds ◽  
The Individual ◽  
Germination And Growth

1. The distribution of phospholipase D (phosphatidylcholine phosphatido-hydrolase, EC 3.1.4.4) was examined in the tissues of a number of plants and seeds. 2. The highest activities were found in various swollen storage tissues of certain plants: cabbage, central stalk; cauliflower, flower; celery, swollen leaf stalk; Kohl rabi, swollen stem; carrot, root; pea and marrow, seed. 3. Appreciable activity was retained in pea seeds for at least 1 year after drying. After germination and growth in the dark the total activity present in the cotyledons and also in the whole seedling decreased. 4. In the growing pea seedling (7 days old), about 3% of the total activity was in the plumule, 9% in the root and the remainder in the cotyledons. However, the activity in the root on a dry-weight basis was higher than that in the cotyledons. In both the root and the plumule the activity on a wet- or a dry-weight basis was highest in the growing tip. 5. The activity per dry weight in the roots and aerial parts of pea plants declined to low values as growth continued, but roots struck from cuttings of mature plants showed the same high activity as found in roots from young seedlings with cotyledons attached. 6. The total phospholipids present in the cotyledons of pea seeds were depleted on germination and growth. Of the individual phospholipids, phosphatidylcholine and phosphatidylethanolamine showed the same loss in 11 days as the whole phospholipid fraction, whereas phosphatidylinositol was decreased to a greater extent and cardiolipin and phosphatidylserine were not decreased. There was no increase of phosphatidic acid, as might have been expected if the phospholipids had disappeared through phospholipase D hydrolysis. 7. It is concluded that phospholipase D in plant storage tissues and seeds may be related to the rapid growth involved in their formation rather than being necessary for the utilization of their food reserve substances.

scholarly journals Impact of Different Seed Rates and Knocking Down Days of Sesbania on Weed Density and Yield of Dry Direct Seeded Rice

2018 ◽  
Vol 6 (4) ◽  
pp. 359-365
Author(s):  
Sunil Kumar Chaudhary ◽  
Santosh Marahatta ◽  
Manisha Chaudhary
Keyword(s):  
Monsoon Season ◽  
Dry Weight ◽  
Effective Control ◽  
Seed Rate ◽  
Weed Density ◽  
Plot Size ◽  
Major Constraint ◽  
Direct Seeded ◽  
The Individual ◽  
Plot Design

The weed is a major constraint of dry-direct seeded rice (DDSR) due to change in establishment methods and shifting weed flora towards competitive grasses and sedges. To minimize the weed density, its species and dry weight with brown manuring and for optimizing the yield of DDSR, the experiment was conducted during monsoon season of 2014 at Chitwan, Nepal. The experiment was done using a strip plot design to find the optimum seed rate and killing date of Sesbania under rice-Sesbania co-culture. Among different seed rates (60, 80, 100 kg ha-1) and knocking down days (21, 28, 35 & 42 DAS) of Sesbania, the optimum seed rate of Sesbania was 102 kg ha-1 and killing date was 32 days. The individual plot size was 5 x 4 m2. The growing of Sesbania with 100 kg seeds ha-1 along with its knocked down at 28 DAS was seen best to minimize the weeds having better performance of rice. The experiment clearly demonstrated the importance of brown manuring on effective control of weeds and on grain yield of rice under dry direct seeded rice. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 359-365

scholarly journals The Evolutionary Dynamics of Genetic Incompatibilities Introduced by Duplicated Genes in Arabidopsis thaliana

2020 ◽  
Author(s):  
Wen-Biao Jiao ◽  
Vipul Patel ◽  
Jonas Klasen ◽  
Fang Liu ◽  
Petra Pecinkova ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Population History ◽  
Duplicated Genes ◽  
Genetic Incompatibility ◽  
Additional Gene ◽  
Genomic Changes ◽  
Gene Copies ◽  
Geographic Origins ◽  
The Individual

Abstract Although gene duplications provide genetic backup and allow genomic changes under relaxed selection, they may potentially limit gene flow. When different copies of a duplicated gene are pseudofunctionalized in different genotypes, genetic incompatibilities can arise in their hybrid offspring. Although such cases have been reported after manual crosses, it remains unclear whether they occur in nature and how they affect natural populations. Here, we identified four duplicated-gene based incompatibilities including one previously not reported within an artificial Arabidopsis intercross population. Unexpectedly, however, for each of the genetic incompatibilities we also identified the incompatible alleles in natural populations based on the genomes of 1,135 Arabidopsis accessions published by the 1001 Genomes Project. Using the presence of incompatible allele combinations as phenotypes for GWAS, we mapped genomic regions that included additional gene copies which likely rescue the genetic incompatibility. Reconstructing the geographic origins and evolutionary trajectories of the individual alleles suggested that incompatible alleles frequently coexist, even in geographically closed regions, and that their effects can be overcome by additional gene copies collectively shaping the evolutionary dynamics of duplicated genes during population history.

Total growth of a black spruce (Picea mariana) tree at Chalk River, Ontario, Canada

1969 ◽  
Vol 47 (1) ◽  
pp. 73-84 ◽  
Author(s):  
D. A. Fraser ◽  
D. McGuire
Keyword(s):  
Root Formation ◽  
Black Spruce ◽  
High Growth ◽  
Dry Weight ◽  
Productive Capacity ◽  
Annual Rings ◽  
Aerial Parts ◽  
Grand Total ◽  
Total Growth ◽  
The Individual

Apical and radial growth in trunk, branches, and roots, together with needle and cone distribution, were studied in a black spruce tree 31 years old and [Formula: see text] high. Growth of aerial parts was summarized as follows: (1) according to years of formation (oblique summation); (2) transversely on trunk inter-nodes (horizontal summation); and (3) according to the position of the annual rings, and the branch internodes (and needles) in relation to the pith or trunk (vertical summation). Root segments were classified on the basis of their diameter and distance from the trunk. Calculated on a dry-weight basis, the trunk accounted for 37%, the branches for 24%, the roots for 21%, and the needles for 18% of the grand total of 81 kg.The tree had 7.8 million needles when sampled in the fall of 1963, one-quarter of which were formed during the last 2 years of growth. Dry weight of individual needles varied with both position and age. While needles of the same season from the lower part of the crown exceeded those from the upper part in length, the reverse was true for the individual dry-weight content.In black spruce, cone periodicity, while distinct, is not as pronounced as in white spruce. The productive capacity of one "average" needle was estimated in terms of apical growth, trunk wood, and needle and root formation.

Methods of analysing competition with special reference to herbage plants: I. Establishment

1973 ◽  
Vol 81 (1) ◽  
pp. 77-89 ◽  
Author(s):  
J. Hill ◽  
Y. Shimamoto
Keyword(s):  
Special Reference ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Natural Populations ◽  
Dry Weight ◽  
The Other ◽  
Replacement Series ◽  
Genotype Combination ◽  
South Wales ◽  
Gains And Losses

SummaryA diallel arrangement, which incorporated the essential features of the de Wit density replacement series, was employed to study the effects of competition amongst five genotypes of perennial ryegrass (Lolium perenne). Of the five genotypes concerned two were derived from S·24, two were collected from natural populations in South Wales, while the remaining genotype originated from S· 23. These five genotypes were grown as monocultures and in all ten binary combinations. Within each combination there were three mixture proportions, namely 75:25, 50:50 and 25:75. All mixtures and monocultures were represented by two boxes, one of which was cut at 3-week intervals (frequent cutting) the other being cut at 6-week intervals (infrequent cutting). At each cut all plants within the appropriate mixtures and monocultures were harvested individually and their dry weight recorded.The results obtained over the first 18 weeks of the experiment (i. e. the first three complete growing periods) establish that competition is occurring in nine of the ten binary combinations. Within these nine combinations competition may be classified into one of three groups: first, it may be compensatory, in which the gains and losses incurred by the two components counterbalance; secondly, it may be positive complete complementation, where the advantage gained by the stronger component is such that the mixture performance matches that of the better monoculture, and thirdly, it may be positive over-complementation, where the yield of the better monoculture is surpassed by the mixture. Further tests disclose that a long-leaved S· 24 genotype is the strongest competitor, while a short-leaved, prostrate, indigenous genotype proves to be by far the weakest competitor.Estimates of the equilibrium proportions for each genotype combination suggest that most combinations are expected to become monocultures of the strongest component, with only the combination between the long-leaved indigenous and longleaved S· 23 genotypes remaining a mixture at equilibrium. None of these equilibria coincides with the proportions required to achieve maximum productivity from a particular combination. The results are considered in relation to the known characteristics of these five perennial ryegrass genotypes, while the wider agronomic implications are also discussed.

Age-bodyweight relationships to lung growth in the F344 rat as indexed by lung weight measurements

1986 ◽  
Vol 20 (3) ◽  
pp. 189-194 ◽  
Author(s):  
S. I. Tillery ◽  
B. E. Lehnert
Keyword(s):  
Dry Weight ◽  
Lung Growth ◽  
Lung Weight ◽  
Lung Lobe ◽  
F344 Rat ◽  
Wet Weight ◽  
The Individual ◽  
The Right ◽  
F344 Rats ◽  
Lung Lobes

Measurements of the total lung weights and the individual weights of the lung lobes of male F344 rats ranging in age from about 30 days to 140 days or more were made in order to determine how lung growth and the growths of the individual lung lobes relate to bodyweight over the course of maturation of this species. Additionally, in this study we also (1) compared how each lung lobe grows relative to total lung growth, (2) evaluated the ratios of lung dry weight to wet weight and (3) obtained information on the weights of the trachea and extra-hilar main-stem bronchi as the F344 rat matures. The wet weights WLT of the trachea-lung preparations and the pooled lobe weights WPL as functions of rat bodyweight WB could be readily described by the following logarithmic expressions: WLT = 0·596 ln WB - 1·923, r = 0·95; WPL = 0·464 ln WB - 1·566, r = 0·96. Expressed as percentages of the pooled lobe weights, the individual lobes remained at constant values as the animals grew with the exception of the right caudal lobe which decreased between bodyweights of 72 and 96 g; absolute wet weight measurements of the individual lobes indicated that the right cranial, right middle and right intermediate lobes actually decreased in weight between bodyweights of 300 and 385 g. The dry weights of the lobes consistently represented approximately 22% of the wet weights regardless of animal age or bodyweight, and on average the airways represented about 20% of the weights of the intact airway-lung preparations over the course of animal maturation.

HORDEIN VARIATION IN WILD (HORDEUM SPONTANEUM) AND CULTIVATED (H. VULGARE) BARLEY

1979 ◽  
Vol 21 (3) ◽  
pp. 391-404 ◽  
Author(s):  
Hans Doll ◽  
A. H. D. Brown
Keyword(s):  
Linkage Disequilibrium ◽  
Wild Species ◽  
Storage Protein ◽  
Natural Populations ◽  
Hordeum Spontaneum ◽  
Allele Frequencies ◽  
Evolutionary Processes ◽  
Highly Correlated ◽  
The Individual ◽  
Allozyme Loci

The storage protein hordein contains two major groups of polypeptides which are highly polymorphic in barley, and in its evolutionary progenitor Hordeum spontaneum Koch. Crosses between the two species showed that the complex electrophoretic phenotypes within the two groups of polypeptides are governed by codominant alleles at two corresponding loci, Hor-1 and Hor-2, which are moderately linked (11% ± 2). In natural populations of the wild species, the two complex hordein loci were much more polymorphic than the allozyme loci. Furthermore, the variation at these two loci was highly correlated so that individuals differ from one another at both loci much more frequently than expected from the allele frequencies at the individual loci. Considerable hordein variation was also present in Composite Cross XXI, and there was evidence of reassortment of patterns by the seventeenth generation. Thus the complex hordein loci, with their extreme diversity and linkage disequilibrium, are ideal markers for monitoring evolutionary processes in both natural, or composite cross populations.

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