Studies on the genetic control of some physiological processes in seeds

1983 ◽  
Vol 61 (12) ◽  
pp. 3561-3567 ◽  
Author(s):  
J. M. Naylor
Keyword(s):  
Drought Stress ◽  
Genetic Variability ◽  
Seed Dormancy ◽  
Seed Viability ◽  
Avena Fatua ◽  
Hormonal Control ◽  
Weed Species ◽  
Physiological Processes ◽  
Highly Sensitive

Evidence is presented that genetic variability affecting duration of seed dormancy and seed viability exists in field populations of Avena fatua L. and that this variability is an important factor in the persistence of this weed species in allowing populations to adapt to particular cultural weed-control practices. Duration of seed dormancy is controlled by several or many genes, the effects of which are manifested in at least two physiologically distinct physiological blocks. Expression of genotypes which confer long-term seed dormancy is highly sensitive to temperature and drought stress experienced by maternal plants during seed development. Naturally inbreeding families characterized by long-term dormancy also exhibit rigorous hormonal control of the synthesis of at least one hydrolase in endosperm (α-amylase). This association of physiological traits apparently is not due to pleiotropy but rather to coadaptive multilocus organization.

Time of wild oat (Avena fatua) panicle clipping influences seed viability

Weed Science ◽  
2020 ◽  
Vol 68 (3) ◽  
pp. 260-267
Author(s):  
Breanne D. Tidemann ◽  
K. Neil Harker ◽  
Eric N. Johnson ◽  
Christian J. Willenborg ◽  
Steve J. Shirtliffe
Keyword(s):  
Seed Viability ◽  
Avena Fatua ◽  
Management Technique ◽  
Wild Oat ◽  
Viable Seed ◽  
Crop Canopy ◽  
Long Term Effects ◽  
Weed Species ◽  
Seed Moisture

AbstractWild oat (Avena fatua L.) is one of the most problematic weed species in western Canada due to widespread populations, herbicide resistance, and seed dormancy. In wheat (Triticum aestivum L.), and especially in shorter crops such as lentil (Lens culinaris Medik.), A. fatua seed panicles elongate above the crop canopy, which can facilitate physical cutting of the panicles (clipping) to reduce viable seed return to the seedbank. However, the viability of A. fatua seed at the time of panicle elongation is not known. The objective of this study was to determine the viability of A. fatua seed at successive time intervals after elongation above a wheat or lentil crop canopy. A 2-yr panicle clipping and removal study in wheat and lentil was conducted in Lacombe, AB, and Saskatoon, SK, in 2015 and 2016 to determine the onset of viability in A. fatua seeds at successive clipping intervals. Manual panicle clipping of A. fatua panicles above each crop canopy began when the majority of panicles were visible above respective crop canopies and continued weekly until seed shed began. At the initiation of panicle clipping, A. fatua seed viability was between 0% and 10%. By the last clipping treatment (approximately 6 to 7 wk after elongation), 95% of the A. fatua seeds were viable. Seed moisture and awn angle were not good predictors of A. fatua viability, and therefore were unlikely to provide effective tools to estimate appropriate timing for implementation of A. fatua clipping as a management technique. Based on A. fatua seed viability, earlier clipping of A. fatua is likely to be more effective in terms of population management and easier to implement in shorter crops such as lentil. Investigations into long-term effects of clipping on A. fatua populations are needed to evaluate the efficacy of this management strategy on A. fatua.

Genetic adaptation for seed dormancy in Avena fatua

1976 ◽  
Vol 54 (3-4) ◽  
pp. 306-312 ◽  
Author(s):  
J. M. Naylor ◽  
S. Jana
Keyword(s):  
Genetic Variability ◽  
Seed Dormancy ◽  
Natural Populations ◽  
Avena Fatua ◽  
Genetic Adaptation ◽  
Agronomic Practices ◽  
Primary Dormancy ◽  
Local Populations ◽  
Wild Oats

Genetic variability affecting duration of primary dormancy is demonstrated in natural populations of wild oats. Marked differences were found among local populations in germination behavior. The evidence suggests that these differences result in part from genetic adaptation to agronomic practices.

Dormancy studies in seed of Avena fatua. 13. Influence of drought stress during seed development on duration of seed dormancy

1982 ◽  
Vol 60 (6) ◽  
pp. 1016-1020 ◽  
Author(s):  
Ramma Sawhney ◽  
J. M. Naylor
Keyword(s):  
High Temperature ◽  
Water Stress ◽  
Drought Stress ◽  
Seed Development ◽  
Seed Dormancy ◽  
Pure Line ◽  
Avena Fatua ◽  
Primary Dormancy ◽  
Pure Lines

Plants of genetically dormant (D) and nondormant (ND) pure lines of Avena fatua were exposed to water stress during seed development. In comparison with normally well-watered controls, seeds produced by water-stressed plants exhibited shorter duration of primary dormancy. The magnitude of the effect varied among D families, but was consistently greater than in ND families.It is concluded that the dormancy phenotype of D lines is highly plastic and that the responses to high temperature and water stress are similar in a given pure line.

Coadaptation of seed dormancy and hormonal dependence of α-amylase production in endosperm segments of Avena fatua

1982 ◽  
Vol 60 (7) ◽  
pp. 1142-1147 ◽  
Author(s):  
Mahesh K. Upadhyaya ◽  
James M. Naylor ◽  
Graham M. Simpson
Keyword(s):  
Seed Dormancy ◽  
Reducing Sugars ◽  
Avena Fatua ◽  
Multiple Alleles ◽  
Wild Oats ◽  
Amylase Production ◽  
Hormonal Dependence ◽  
Oat Seeds ◽  
Pure Lines

Autonomous (independent of the germinating embryo) α-amylase production was compared in the endosperm segments of some genetically pure lines of Avena fatua L. (wild oats) differing in the duration of their seed dormancy. Endosperm segments from six randomly taken dormant lines showed no α-amylase production unless gibberellic acid (GA3) was supplied. In contrast, endosperm segments from four out of six nondormant lines produced and released substantial amounts of α -amylase and reducing sugars. Thus, natural selection has resulted in coadaptation of seed dormancy and a rigorous dependence of endosperm hydrolysis on gibberellins produced by the germinating embryo. The variability in the degree of autonomy amongst nondormant lines indicates that the observed coupling of these two traits in dormant lines is not due to simple pleiotropy, but probably reflects the action of multiple genetic loci or multiple alleles. These results also indicate that long-term endosperm stability confers little advantage in wild oat seeds predisposed to brief periods of residence in soil.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Influence of NPK fertilization on weed flora in maize field

2014 ◽  
Vol 63 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Éva Lehoczky ◽  
M. Kamuti ◽  
N. Mazsu ◽  
J. Tamás ◽  
D. Sáringer-Kenyeres ◽  
...  
Keyword(s):  
Plant Nutrition ◽  
Crop Production ◽  
N Availability ◽  
Weed Species ◽  
Negative Effects ◽  
Production Factors ◽  
Maize Field ◽  
Weed Flora ◽  
Npk Fertilization

Plant nutrition is one of the most important intensification factors of crop production. The utilization of nutrients, however, may be modified by a number of production factors, including weed presence. Thus, the knowledge of occurring weed species, their abundance, nutrient and water uptake is extremely important to establish an appropriate basis for the evaluation of their risks or negative effects on crops. That is why investigations were carried out in a long-term fertilization experiment on the influence of different nutrient supplies (Ø, PK, NK, NPK) on weed flora in maize field.The weed surveys recorded similar diversity on the experimental area: the species of A. artemisiifolia, S. halepense and D. stramonium were dominant, but C. album and C. hybridum were also common. These species and H. annuus were the most abundant weeds.Based on the totalized and average data of all treatments, density followed the same tendency in the experimental years. It was the highest in the PK treated and untreated plots, and significantly exceeded the values of NK fertilized areas. Presumably the better N availability promoted the development of nitrophilic weeds, while the mortality of other small species increased.Winter wheat and maize forecrops had no visible influence on the diversity and the intensity of weediness. On the contrary, there were consistent differences in the density of certain weed species in accordance to the applied nutrients. A. artemisiifolia was present in the largest number in the untreated control and PK fertilized plots. The density of S. halepense and H. annuus was also significantly higher in the control areas. The number of their individuals was smaller in those plots where N containing fertilizers were used. Contrary to them, the density of D. stramonium, C. album and C. hybridum was the highest in the NPK treatments.

scholarly journals Understanding sex differences in long-term blood pressure regulation: insights from experimental studies and computational modeling

2019 ◽  
Vol 316 (5) ◽  
pp. H1113-H1123 ◽  
Author(s):  
Sameed Ahmed ◽  
Rui Hu ◽  
Jessica Leete ◽  
Anita T. Layton
Keyword(s):  
Blood Pressure ◽  
Sex Differences ◽  
Computational Models ◽  
Experimental Studies ◽  
Pressure Control ◽  
Blood Pressure Regulation ◽  
Pressure Regulation ◽  
Physiological Processes ◽  
Key Players

Sex differences in blood pressure and the prevalence of hypertension are found in humans and animal models. Moreover, there has been a recent explosion of data concerning sex differences in nitric oxide, the renin-angiotensin-aldosterone system, inflammation, and kidney function. These data have the potential to reveal the mechanisms underlying male-female differences in blood pressure control. To elucidate the interactions among the multitude of physiological processes involved, one may apply computational models. In this review, we describe published computational models that represent key players in blood pressure regulation, and highlight sex-specific models and their findings.

scholarly journals Long-Term Cocirculation of Two Strains of Pepino Mosaic Virus in Tomato Crops and Its Effect on Population Genetic Variability

2020 ◽  
Vol 110 (1) ◽  
pp. 49-57 ◽  
Author(s):  
C. Alcaide ◽  
M. P. Rabadán ◽  
M. Juárez ◽  
P. Gómez
Keyword(s):  
Genetic Variability ◽  
Mosaic Virus ◽  
Evolutionary Dynamics ◽  
Geographical Area ◽  
Viral Fitness ◽  
Mixed Infections ◽  
Supporting Evidence ◽  
Pepino Mosaic Virus ◽  
Nucleotide Variability

Mixed viral infections are common in plants, and the evolutionary dynamics of viral populations may differ depending on whether the infection is caused by single or multiple viral strains. However, comparative studies of single and mixed infections using viral populations in comparable agricultural and geographical locations are lacking. Here, we monitored the occurrence of pepino mosaic virus (PepMV) in tomato crops in two major tomato-producing areas in Murcia (southeastern Spain), supporting evidence showing that PepMV disease-affected plants had single infections of the Chilean 2 (CH2) strain in one area and the other area exhibited long-term (13 years) coexistence of the CH2 and European (EU) strains. We hypothesized that circulating strains of PepMV might be modulating the differentiation between them and shaping the evolutionary dynamics of PepMV populations. Our phylogenetic analysis of 106 CH2 isolates randomly selected from both areas showed a remarkable divergence between the CH2 isolates, with increased nucleotide variability in the geographical area where both strains cocirculate. Furthermore, the potential virus–virus interaction was studied further by constructing six full-length infectious CH2 clones from both areas, and assessing their viral fitness in the presence and absence of an EU-type isolate. All CH2 clones showed decreased fitness in mixed infections and although complete genome sequencing indicated a nucleotide divergence of those CH2 clones by area, the magnitude of the fitness response was irrespective of the CH2 origin. Overall, these results suggest that although agroecological cropping practices may be particularly important for explaining the evolutionary dynamics of PepMV in tomato crops, the cocirculation of both strains may have implications on the genetic variability of PepMV populations.

Dormancy studies in seed of Avena fatua. 10. On the inheritance of germination behaviour

1979 ◽  
Vol 57 (15) ◽  
pp. 1663-1667 ◽  
Author(s):  
S. Jana ◽  
S. N. Acharya ◽  
J. M. Naylor
Keyword(s):  
Seed Dormancy ◽  
Avena Fatua ◽  
Seed Maturation ◽  
Germination Behaviour ◽  
Parental Lines ◽  
Pure Lines

Breeding experiments were performed with pure lines of Avena fatua differing characteristically in duration of primary seed dormancy. The results indicate that the parental lines differ for at least three genes controlling rate of afterripening. It is evident that at least two of these genes influence the rate of afterripening at different periods after seed maturation.

scholarly journals Barley Seeds miRNome Stability during Long-Term Storage and Aging

2021 ◽  
Vol 22 (9) ◽  
pp. 4315
Author(s):  
Marta Puchta ◽  
Jolanta Groszyk ◽  
Magdalena Małecka ◽  
Marek D. Koter ◽  
Maciej Niedzielski ◽  
...  
Keyword(s):  
Seed Viability ◽  
Small Rna Sequencing ◽  
The Novel ◽  
Seed Aging ◽  
Long Term Storage ◽  
Novel Mirna ◽  
Complex Biological Process ◽  
Almost All ◽  
Term Storage

Seed aging is a complex biological process that has been attracting scientists’ attention for many years. High-throughput small RNA sequencing was applied to examine microRNAs contribution in barley seeds senescence. Unique samples of seeds that, despite having the same genetic makeup, differed in viability after over 45 years of storage in a dry state were investigated. In total, 61 known and 81 novel miRNA were identified in dry seeds. The highest level of expression was found in four conserved miRNA families, i.e., miR159, miR156, miR166, and miR168. However, the most astonishing result was the lack of significant differences in the level of almost all miRNAs in seed samples with significantly different viability. This result reveals that miRNAs in dry seeds are extremely stable. This is also the first identified RNA fraction that is not deteriorating along with the loss of seed viability. Moreover, the novel miRNA hvu-new41, with higher expression in seeds with the lowest viability as detected by RT-qPCR, has the potential to become an indicator of the decreasing viability of seeds during storage in a dry state.

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