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.

Dormancy studies in seed of Avena fatua. 9. Demonstration of genetic variability affecting the response to temperature during seed development

1979 ◽  
Vol 57 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Ramma Sawhney ◽  
J. M. Naylor
Keyword(s):  
High Temperature ◽  
Seed Development ◽  
Avena Fatua ◽  
Temperature Sensitive ◽  
Primary Dormancy ◽  
Wild Oats ◽  
Physiological Processes ◽  
Pure Lines ◽  
Response To Temperature ◽  
Two Temperature

Experiments are reported which demonstrate characteristic differences among pure lines of wild oats in the degree to which seed dormancy is influenced by temperature during seed development. In some lines, high temperature during seed maturation greatly reduced the duration of primary dormancy; in others, this effect was relatively slight. Evidence is discussed that two temperature-sensitive physiological processes influence the duration of dormancy in this species.

Variation Within Pure Lines of Wild Oats (Avena fatua) in Relation to Degree of Primary Dormancy

Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 859-864 ◽  
Author(s):  
Stephen W. Adkins ◽  
Mary Loewen ◽  
Stephen J. Symons
Keyword(s):  
Seed Development ◽  
Development Time ◽  
Morphological Characters ◽  
Avena Fatua ◽  
Primary Dormancy ◽  
Wild Oats ◽  
Low Degrees ◽  
Pure Lines ◽  
High Degree ◽  
B Lines

The germination of caryopses on water or GA3 solutions was used to characterize the degree of primary dormancy present in the seed progeny of 10 genetically pure lines of wild oats (Avena fatua L. # AVEFA). These 10 lines represented a range of types from lines exhibiting no dormancy to those with a high degree of dormancy. Repeated propagation of these pure lines under constant environmental conditions identified several genetically inherited characters that were associated with the inherited differences in degree of primary dormancy. Correlation of the seed development period, number of primary caryopses produced, and caryopsis moisture content to the degree of primary dormancy shows: a) Lines characterized by low degrees of primary dormancy were, in general, those that had a short seed development time and produced few heavy seed low in percent water; and b) lines characterized by high degrees of primary dormancy were, in general, those that had a long seed development time and produced many light seed high in percent water. The adaptive advantage of the coupling of physiological and morphological characters with degree of dormancy is discussed and the possibility that some characters are determined by others is indicated.

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.

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.

A study of the relationship between seed dormancy and pentose phosphate pathway activity in Avena fatua

1983 ◽  
Vol 61 (3) ◽  
pp. 667-670 ◽  
Author(s):  
E. P. Fuerst ◽  
M. K. Upadhyaya ◽  
G. M. Simpson ◽  
J. M. Naylor ◽  
S. W. Adkins
Keyword(s):  
Seed Dormancy ◽  
Pentose Phosphate Pathway ◽  
Krebs Cycle ◽  
Pure Line ◽  
Pentose Phosphate ◽  
Avena Fatua ◽  
Wild Oats ◽  
Gibberellin Treatment ◽  
The Relationship ◽  
Increased Activity

The hypothesis that loss of seed dormancy is associated with an increased activity of the pentose phosphate pathway (PPP) relative to glycolysis and the Krebs cycle was tested. The PPP activity was monitored by measuring the C6/C1 ratio in embryos excised from incubated caryopses of two genetically pure nondormant (ND) lines and in three dormant (D) lines of Avena fatua L., the wild oat. The C6/C1 ratios of all lines were similar at the commencement of incubation. In the two ND lines the ratio increased steadily prior to and during emergence of the radicle. In the three D lines the ratio increased during the first 24 h and then remained almost constant; there was no germination. When gibberellin treatment was used to overcome dormancy in the D lines, the C6/C1 ratio increased during the first 24 h in two of the lines and continued to increase parallel to germination in a manner similar to normal germination in ND lines. In the third D line, despite loss of dormancy from gibberellin treatment, the ratio did not increase after 24 h. Loss of dormancy during dry storage of seeds of a D-type pure line was accompanied by an increase in the C6/C1 ratio, as measured in freshly imbibed seeds. This indicates a decreased activity of the PPP relative to glycolysis and the Krebs cycle. These findings are contrary to Roberts's hypothesis that loss of dormancy in wild oats is associated with a relative decrease in the C6/C1 ratio.

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.

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.

scholarly journals Impact of Soil Water Stress at Seed Development Stage on Phenology, Fecundity and Seed Dormancy of Avena sterilis ssp. ludoviciana

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 1
Author(s):  
Mohammad Ali ◽  
Michael Widderick ◽  
Alwyn Williams ◽  
Steve Adkins
Keyword(s):  
Water Stress ◽  
Seed Development ◽  
Seed Dormancy ◽  
Development Stage ◽  
Wheat Crop ◽  
Wild Oat ◽  
Dry Period ◽  
Avena Sterilis ◽  
Soil Water Stress ◽  
No Till

Wild oat (Avena sterilis ssp. ludoviciana (Durieu) Nyman) is considered the most difficult-to-control winter weed in the northern grain region (NGR) of Australia particularly following the adoption of no-till conservation agriculture and the enhanced reliance on herbicides for weed control. A diversity of survival mechanisms is responsible for its persistence in no-till conservation cropping. Among them long-term, variable seed dormancy is the most important. A number of environmental stresses (for example drought) are known to affect the seed dormancy status. We hypothesized that the increasing frequency of hot and dry period in late winter/early spring season in the NGR might help to mature and shed less dormant wild oat seeds before the wheat crop is harvested. This early shedding of highly germinable seed better aids persistence in no-till conservation cropping systems. Our research showed that soil water stress applied at seed development stage resulted in lower number (16–22% less) of early maturing (5–20 days earlier) less dormant (28% less) seeds compared with control plants. This observation was made for a number of biotypes either coming from within one location or between locations within the NGR. Thus, the frequent hot and dry period at the time of seed development in the NGR is responsible for production of less dormant Avena sterilis ssp. ludoviciana seeds where no-till conservation cropping is helping to retain these seeds on the top soil. Under favourable germination conditions in the following season these less dormant seeds will immediately be available to re-infest the autumn/winter-sown wheat crop.

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