CYTOLOGICAL STUDIES IN BROMUS SPECIES, SECTION BROMOPSIS

1961 ◽  
Vol 39 (4) ◽  
pp. 757-773 ◽  
Author(s):  
M. R. Hanna
Keyword(s):  
Interspecific Hybridization ◽  
Seed Set ◽  
Significant Negative Correlation ◽  
B Chromosome ◽  
Meiotic Behavior ◽  
Stainable Pollen ◽  
Meiotic Irregularities ◽  
Wide Range ◽  
Positive Correlations ◽  
Bromus Erectus

Chromosome numbers and meiotic behavior were determined in clones of Bromus inermis, Bromus pumpellianus, and the Bromus erectus complex. Clones of B. inermis were octoploid (2n = 56) or near-octoploid, one aneuploid having 2n = 54 chromosomes. B. pumpellianus clones were octoploid, with one bearing a B chromosome. B. erectus-type clones had 56, 59, 65, or 70 chromosomes. Meioses varied widely among plants in extent of irregularity. Meiotic behavior was studied in detail and the sequential interrelationships of irregularities at meiotic stages analyzed. Significant or highly significant positive correlations were obtained for the B. pumpellianus clones between percentages of non-stainable pollen and frequencies of metaphase I univalents, anaphase II laggards, and quartet micronuclei. These relationships were non-significant for the B. inermis and B. erectus-type clones. A significant negative correlation was determined between percentage of non-stainable pollen and percentage of seed set following open pollination, but other relationships between meiotic irregularities or pollen stainability and seed-setting characteristics were non-significant. The wide range in chromosome number and meiotic behavior encountered in material commonly distributed on this continent as "B. erectus” may be due to interspecific hybridization in nurseries in which Bromus introductions are grown. Interspecific hybridization may be partially responsible also for aneuploidy and meiotic irregularity in B. inermis.

scholarly journals Phenotypic Characterisation for Growth and Nut Characteristics Revealed the Extent of Genetic Diversity in Wild Macadamia Germplasm

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 680
Author(s):  
Thuy T. P. Mai ◽  
Craig M. Hardner ◽  
Mobashwer M. Alam ◽  
Robert J. Henry ◽  
Bruce L. Topp
Keyword(s):  
Genetic Diversity ◽  
Growth Traits ◽  
Principal Component ◽  
Conservation Strategies ◽  
Wild Germplasm ◽  
Phenotypic Characterisation ◽  
Wide Range ◽  
Genetic And Environmental Factors ◽  
Positive Correlations ◽  
Wild Accessions

Macadamia is a recently domesticated Australian native nut crop, and a large proportion of its wild germplasm is unexploited. Aiming to explore the existing diversity, 247 wild accessions from four species and inter-specific hybrids were phenotyped. A wide range of variation was found in growth and nut traits. Broad-sense heritability of traits were moderate (0.43–0.64), which suggested that both genetic and environmental factors are equally important for the variability of the traits. Correlations among the growth traits were significantly positive (0.49–0.76). There were significant positive correlations among the nut traits except for kernel recovery. The association between kernel recovery and shell thickness was highly significant and negative. Principal component analysis of the traits separated representative species groups. Accessions from Macadamia integrifolia Maiden and Betche, M. tetraphylla L.A.S. Johnson, and admixtures were clustered into one group and those of M. ternifolia F. Muell were separated into another group. In both M. integrifolia and M. tetraphylla groups, variation within site was greater than across sites, which suggested that the conservation strategies should concentrate on increased sampling within sites to capture wide genetic diversity. This study provides a background on the utilisation of wild germplasm as a genetic resource to be used in breeding programs and the direction for gene pool conservation.

POLLEN PRODUCTION AND DISSEMINATING PROPERTIES OF TRITICALE RELATIVE TO WHEAT

1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER
Keyword(s):  
Seed Set ◽  
Marker Gene ◽  
Pollen Grains ◽  
Triticum Aestivum L ◽  
Hybrid Seed Production ◽  
Pollen Production ◽  
Hexaploid Triticale ◽  
Anther Length ◽  
Anther Extrusion ◽  
Wide Range

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.

scholarly journals Perceptions and Attitudes towards Mules in a Group of Sodiers

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1009
Author(s):  
Javiera Lagos ◽  
Manuel Rojas ◽  
Joao B. Rodrigues ◽  
Tamara Tadich
Keyword(s):  
Text Mining ◽  
Pain Perception ◽  
Health Needs ◽  
Emotional Needs ◽  
Mountainous Areas ◽  
Working Capacity ◽  
Perceptions And Attitudes ◽  
Wide Range ◽  
Positive Correlations ◽  
Word Attention

Mules are essential for pack work in mountainous areas, but there is a lack of research on this species. This study intends to assess the perceptions, attitudes, empathy and pain perception of soldiers about mules, to understand the type of human–mule relationship. For this, a survey was applied with closed-ended questions where the empathy and pain perception tools were included and later analyzed through correlations. Open-ended questions were analyzed through text mining. A total of 73 soldiers were surveyed. They had a wide range of ages and years of experience working with equids. Significant positive correlations were found between human empathy, animal empathy and pain perception. Soldiers show a preference for working with mules over donkeys and horses. Text mining analysis shows three clusters associated with the mules’ nutritional, environmental and health needs. In the same line, relevant relations were found for the word “attention” with “load”, “food”, and “harness”. When asked what mules signify for them, two clusters were found, associated with mules’ working capacity and their role in the army. Relevant relations were found between the terms “mountain”, “support”, and “logistics”, and also between “intelligent” and “noble”. To secure mules’ behavioral and emotional needs, future training strategies should include behavior and welfare concepts.

The influence of floral morph ratios and low plant density on mating and fertility in a tristylous colonizing species

Botany ◽  
2018 ◽  
Vol 96 (8) ◽  
pp. 533-545 ◽  
Author(s):  
Christopher M. Balogh ◽  
Spencer C.H. Barrett
Keyword(s):  
Field Experiment ◽  
Seed Set ◽  
Plant Density ◽  
Pollen Limitation ◽  
Lythrum Salicaria ◽  
Long Distance ◽  
Experimental Conditions ◽  
Wide Range ◽  
Morph Ratios ◽  
Floral Morph

Sexual reproduction in heterostylous populations may be vulnerable to demographic conditions because of the small number of mating types in populations. Here, we investigate mating and fertility under natural and experimental conditions in tristylous Lythrum salicaria L., an invasive species that exhibits a wide range of floral morph ratios and demographic contexts. We grew 147 open-pollinated seed families from six populations with different morph structures to estimate intermorph mating (d). In a field experiment, we used progeny ratios from 47 spatially isolated individuals to estimate d, and measured the intensity of pollen limitation experienced by the morphs. The M- and S-morphs experienced high rates of d, regardless of population size or morph ratio. Estimates for the L-morph revealed low levels of intramorph mating in three dimorphic and two trimorphic populations, but near complete intramorph mating in a monomorphic population. Despite high levels of intermorph mating in the field experiment, the morphs experienced significant pollen limitation of fruit and seed set, but this did not differ in intensity among the morphs. Our field experiment demonstrates that although plant isolation was associated with pollen limitation of seed set, “long-distance” bee-mediated pollen flow served to maintain intermorph mating. Tristyly in L. salicaria is remarkably robust to the demographic variation associated with colonization.

THE CREATININE HEIGHT INDEX: ITS USE IN THE ESTIMATION OF THE DEGREE OF PROTEIN DEPLETION AND REPLETION IN PROTEIN CALORIE MALNOURISHED CHILDREN

PEDIATRICS ◽  
1970 ◽  
Vol 46 (5) ◽  
pp. 696-706
Author(s):  
Fernando E. Viteri ◽  
Jorge Alvarado
Keyword(s):  
Muscle Mass ◽  
Negative Correlation ◽  
Normal Child ◽  
Muscle Wasting ◽  
Significant Negative Correlation ◽  
Clinical Severity ◽  
Creatinine Excretion ◽  
N Retention ◽  
Malnourished Children ◽  
Wide Range

The creatinine height index (CHI), which consists of the following ratio: CHI: 24 hour creatinine excretion of subject 24 hour creatinine excretion of normal child of same height has been devised for estimating the relative muscle mass of children. Age is not considered because children of developing areas are very often retarded in height. The normal CHI is close to 1.0, both in well nourished children and in fully recovered malnourished ones, with heights ranging from 64.8 to 135 cm. Protein calorie malnourished (PCM) children of the edematous type (kwashiorkor and kwashiorkormarasmus) had CHI's ranging from 0.25 to 0.75, lower CHI's were observed in more severely malnourished children and vice versa. In clinically marasmic children (PCM without edema) the CHI ranged from 0.33 to 0.85, independent of the degree of weight deficit or the clinical severity of marasmus, indicating that severe caloric deficiency can occur with a wide range of muscle wasting. No creatinine retention was observed in any PCM children with adequate urine flows. Independent estimates of protein and calorie repletion were obtained during recovery by the use of CHI and weight for height. A significant negative correlation between CHI and N retention was found, indicating the physiological significance of the CHI in estimating protein nutrition.

Correlates and Mediators of Dissociation: Towards a Transtheoretical Perspective

2020 ◽  
pp. 027623662095628
Author(s):  
Damla E. Aksen ◽  
Craig Polizzi ◽  
Steven Jay Lynn
Keyword(s):  
Negative Affect ◽  
Negative Correlation ◽  
Emotion Dysregulation ◽  
Sleep Disturbances ◽  
Significant Negative Correlation ◽  
Unique Variance ◽  
Positive Correlations ◽  
Bidirectional Relations ◽  
Mediational Role

We evaluated variables important to understanding dissociation ( N = 379 undergraduates). We investigated: (a) the correlations among dissociation and impulsivity, alexithymia, mindfulness, negative affect, neuroticism, sleep disturbances, and emotion dysregulation; (b) unique variance of these variables in statistically predicting dissociation scores; and (c) the statistical mediational role of emotion dysregulation and sleep in explaining dissociation. We found significant positive correlations between dissociation and emotion dysregulation, sleep, alexithymia, negative affect, impulsivity, and neuroticism as well as a significant negative correlation between mindfulness and dissociation, consistent with Lynn et al . Sleep, impulsivity, emotion dysregulation, and negative affect uniquely related to and explained significant variance in dissociation, in order from most to least variance accounted for. Sleep partially mediated the relation between emotion dysregulation and dissociation and the relation between impulsivity and dissociation. Emotion dysregulation partially mediated the relation between sleep and dissociation and the relation between impulsivity and dissociation. Additional findings provided support for bidirectional relations between sleep experiences and dissociation and emotion dysregulation and dissociation.

scholarly journals Earth-based observations of impact phenomena

1996 ◽  
Vol 156 ◽  
pp. 81-109
Author(s):  
Philip D. Nicholson
Keyword(s):  
Hubble Space Telescope ◽  
Common Pattern ◽  
Mid Infrared ◽  
Wide Range ◽  
Impact Phenomena ◽  
Infrared Wavelengths ◽  
Positive Correlations ◽  
The Individual ◽  
The Impact ◽  
Size Estimates

Earth-based observations at near- and mid-infrared wavelengths were obtained for at least 15 of the SL9 impacts, ranging from the spectacular G, K and L events to the barely-detected N and V impacts. Although there were a few exceptions, most of the IR lightcurves fit a common pattern of one or two relatively faint precursor flashes, followed several minutes later by the main infrared event as the explosively-ejected plume crashed down onto the jovian atmosphere. Correlations with the impact times recorded by the Galileo spacecraft and plumes imaged by the Hubble Space Telescope lead to an interpretation of the twin precursors in terms of (i) the entry of the bolide into the upper atmosphere, and (ii) the re-appearance of the rising fireball above Jupiter's limb. Positive correlations are observed between the peak IR flux observed during the splashback phase and both pre-impact size estimates for the individual SL9 fragments and the scale of the resulting ejecta deposits. None of the fragments observed to have moved off the main train of the comet by May 1994 produced a significant impact signature. Earth-based fireball temperature estimates are on the order of 750 K, 30-60 sec after impact. For the larger impacts, the unexpectedly protracted fireball emission at 2.3 μm remains unexplained. A wide range of temperatures has been inferred for the splashback phase, where shocks are expected to have heated the re-entering plume material at least briefly to several thousand K, and further modelling is required to reconcile these data.

scholarly journals Oligo-painting and GISH reveal meiotic chromosome biases and increased meiotic stability in synthetic allotetraploid Cucumis ×hytivus with dysploid parental karyotypes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Qinzheng Zhao ◽  
Yunzhu Wang ◽  
Yunfei Bi ◽  
Yufei Zhai ◽  
Xiaqing Yu ◽  
...  
Keyword(s):  
Interspecific Hybridization ◽  
Interspecific Hybrids ◽  
Chromosome Doubling ◽  
Meiotic Chromosome ◽  
Genomic In Situ Hybridization ◽  
Meiotic Behavior ◽  
Cytological Evidence ◽  
Meiotic Stability ◽  
Inbred Family

Abstract Background Meiosis of newly formed allopolyploids frequently encounter perturbations induced by the merging of divergent and hybridizable genomes. However, to date, the meiotic properties of allopolyploids with dysploid parental karyotypes have not been studied in detail. The allotetraploid Cucumis ×hytivus (HHCC, 2n = 38) was obtained from interspecific hybridization between C. sativus (CC, 2n = 14) and C. hystrix (HH, 2n = 24) followed by chromosome doubling. The results of this study thus offer an excellent opportunity to explore the meiotic properties of allopolyploids with dysploid parental karyotypes. Results In this report, we describe the meiotic properties of five chromosomes (C5, C7, H1, H9 and H10) and two genomes in interspecific hybrids and C. ×hytivus (the 4th and 14th inbred family) through oligo-painting and genomic in situ hybridization (GISH). We show that 1) only two translocations carrying C5-oligo signals were detected on the chromosomes C2 and C4 of one 14th individual by the karyotyping of eight 4th and 36 14th plants based on C5- and C7-oligo painting, and possible cytological evidence was observed in meiosis of the 4th generation; 2) individual chromosome have biases for homoeologous pairing and univalent formation in F1 hybrids and allotetraploids; 3) extensive H-chromosome autosyndetic pairings (e.g., H-H, 25.5% PMCs) were observed in interspecific F1 hybrid, whereas no C-chromosome autosyndetic pairings were observed (e.g. C-C); 4) the meiotic properties of two subgenomes have significant biases in allotetraploids: H-subgenome exhibits higher univalent and chromosome lagging frequencies than C-subgenome; and 5) increased meiotic stability in the S14 generation compared with the S4 generation, including synchronous meiosis behavior, reduced incidents of univalent and chromosome lagging. Conclusions These results suggest that the meiotic behavior of two subgenomes has dramatic biases in response to interspecific hybridization and allopolyploidization, and the meiotic behavior harmony of subgenomes is a key subject of meiosis evolution in C. ×hytivus. This study helps to elucidate the meiotic properties and evolution of nascent allopolyploids with the dysploid parental karyotypes.

Complexity trade-offs do not prove the equal complexity hypothesis

2014 ◽  
Vol 50 (2) ◽  
Author(s):  
Gertraud Fenk-Oczlon ◽  
August Fenk
Keyword(s):  
Negative Correlation ◽  
Null Hypothesis ◽  
Quantitative Methods ◽  
Significant Negative Correlation ◽  
Second Step ◽  
Trade Offs ◽  
Monosyllabic Words ◽  
Complexity Hypothesis ◽  
Positive Correlations

AbstractComplexity trade-offs are often considered as evidence for the hypothesis that all languages are equally complex; simplicity in one component of grammar is balanced by complexity in another. According to Shosted (2006), this "negative correlation hypothesis", as he calls it, was never validated using quantitative methods. The present paper recalls, in a first step, our previously found significant negative cross-linguistic correlations between syllable complexity and number of syllables per clause and per word, as well as an almost significant negative correlation between syllable complexity and number of morphological cases. All these correlations indicate complexity trade-offs between subsystems of language, as do the positive correlations found between syllable complexity, number of syllable types, and number of monosyllabic words. In a second step we argue against the view of such complexity trade-offs as proof of the equal complexity hypothesis. This hypothesis is hardly testable for several reasons: As long as it is impossible to quantify the overall complexity of a single language, it is also impossible to compare different languages with respect to that quantity. Secondly, it could – because of its character as a null hypothesis – never be corroborated for principal reasons.

scholarly journals Identification of Chrysanthemum (Chrysanthemum morifolium) Self-Incompatibility

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fan Wang ◽  
Feng-Jiao Zhang ◽  
Fa-Di Chen ◽  
Wei-Min Fang ◽  
Nian-Jun Teng
Keyword(s):  
Small Proportion ◽  
Seed Set ◽  
Staining Method ◽  
Pollen Grains ◽  
Chrysanthemum Morifolium ◽  
Fluorescence Microscope ◽  
Blue Staining ◽  
Self Incompatibility ◽  
Wide Range ◽  
Aniline Blue Staining

There has been a heated argument over self-incompatibilityof chrysanthemum (Chrysanthemum morifolium) among chrysanthemum breeders. In order to solve the argument, we investigated pistil receptivity, seed set, and compatible index of 24 chrysanthemum cultivars. It was found that the 24 cultivars averagely had 3.7–36.3 pollen grains germinating on stigmas at 24 hours after self-pollination through the fluorescence microscope using aniline blue staining method. However, only 10 of them produced self-pollinated seeds, and their seed sets and compatible indexes were 0.03–56.50% and 0.04–87.50, respectively. The cultivar “Q10-33-1” had the highest seed set (56.50%) and compatible index (87.50), but ten of its progeny had a wide range of separation in seed set (0–37.23%) and compatible index (0–68.65). The results indicated that most of chrysanthemum cultivars were self-incompatible, while a small proportion of cultivars were self-compatible. In addition, there is a comprehensive separation of self-incompatibility among progeny from the same self-pollinated self-compatible chrysanthemum cultivar. Therefore, it is better to emasculate inflorescences during chrysanthemum hybridization breeding when no information concerning its self-incompatibility characteristics is available. However, if it is self-incompatible and propagated by vegetative methods, it is unnecessary to carry out emasculation when it is used as a female plant during hybridization breeding.

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