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.

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.

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. 8. Genetic diversity affecting response to temperature

1978 ◽  
Vol 56 (18) ◽  
pp. 2224-2229 ◽  
Author(s):  
J. M. Naylor ◽  
P. Fedec
Keyword(s):  
Genetic Diversity ◽  
Adaptive Significance ◽  
Avena Fatua ◽  
Strong Suppression ◽  
Temperature Range ◽  
Wild Oats ◽  
Pure Lines ◽  
Response To Temperature

Experiments are reported which demonstrate the interaction of temperature with genotype in controlling germination in wild oats. In some pure lines germination of newly matured seeds occurs at all temperatures in the range 4–32 °C. Other pure lines exhibit strong suppression of germination in the midportion of this temperature range. The possible adaptive significance of this dimorphism in nature is discussed.

Temperature control of dormancy and germination in embryos isolated from seeds of dormant and nondormant lines of wild oats (Avena fatua)

1989 ◽  
Vol 67 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Ramma Sawhney
Keyword(s):  
High Temperatures ◽  
Temperature Control ◽  
Temperature Effects ◽  
Avena Fatua ◽  
Temperature Sensitive ◽  
Optimum Temperature ◽  
Apparent Discrepancy ◽  
Primary Dormancy ◽  
Wild Oats ◽  
Sensitive Line

The question of whether the embryo is the site of the observed effect of low and high temperatures during seed maturation on the final dormancy of ripe seeds of wild oats (Avena fatua L.) was investigated. Embryos isolated from seeds of dormant lines germinated within 2–3 weeks of incubation at an optimum temperature (4 °C), irrespective of maturation temperature. However, whole seeds were dormant for several months except for the temperature-sensitive line, AN 86, where relatively high maturation temperatures significantly reduced the period of primary dormancy. There was no difference between the germinative capabilities of embryos isolated from the temperature sensitive AN 86 and the relatively less sensitive line AN 51. Thus, the mechanisms underlying the dormancy of whole seeds, as well as the temperature effects on dormancy, do not appear to reside within the embryo. Further experiments were conducted to resolve the apparent discrepancy between earlier conclusions that embryos of dormant wild oats are dormant and the present findings that they are not. The earlier hypothesis was based on lack of germination in embryos of a nonlocal line, Montana 72, incubated at 20 °C. In the present study, embryos of Montana 72 were not dormant when incubated at 4–12 °C, but were induced to thermodormancy when incubated in temperatures above that range. Embryos of local lines (AN 265, AN 51, and AN 86) germinated readily at all temperatures below 24 °C, but showed thermodormancy above it. Thus, isolated embryos of dormant lines are capable of germination at optimum temperatures, but are thermodormant at relatively high temperatures.

Genetic basis of dormancy and differential response to sodium azide in Avena fatua seeds

1988 ◽  
Vol 66 (4) ◽  
pp. 635-641 ◽  
Author(s):  
S. Jana ◽  
M. K. Upadhyaya ◽  
S. N. Acharya
Keyword(s):  
Sodium Azide ◽  
Time Course ◽  
Genetic Basis ◽  
Differential Response ◽  
Avena Fatua ◽  
Maternal Influence ◽  
Maternal Parent ◽  
Wild Oats ◽  
Respiratory Inhibitor ◽  
Pure Lines

Seven crosses, involving either nondormant × dormant or dormant × dormant pure lines of wild oats (Avena fatua L.), were made. Selfing of the hybrid and further hybridization were carried out to produce the F2 and reciprocal backcross generations. The seed germination time-course curves of the parents, their F1, and segregating generations over a 20-week period were studied. Differences in time course of germination in these generations were interpreted in terms of a minimum of three interacting loci. Two pure lines, AN51 and MO73, differed in their response to sodium azide, a respiratory inhibitor, with the former being more responsive. In crosses between these lines, the F1 seeds were also more responsive when AN51 was used as the maternal parent. This differential response of two dormant pure lines and their reciprocal F1s suggests maternal influence in germination response to sodium azide.

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.

Floret anthesis and pollination in wild oats (Avena fatua)

1985 ◽  
Vol 63 (12) ◽  
pp. 2187-2195 ◽  
Author(s):  
M. V. S. Raju ◽  
G. J. Jones ◽  
G. F. Ledingham
Keyword(s):  
Ambient Temperature ◽  
Water Uptake ◽  
Pollen Grains ◽  
Avena Fatua ◽  
Daily Rhythm ◽  
Temperature Sensitive ◽  
Wide Angle ◽  
Wild Oat ◽  
Canadian Prairies ◽  
Wild Oats

Avena fatua L. (wild oats), an introduced annual, is a successful weed in the cultivated fields of the Canadian prairies. Its inflorescence is a determinate panicle consisting of many spikelets, each of which contains two or three florets. During anthesis, the lodicules in each floret swell after water uptake and cause the lemma to diverge and to establish a wide angle between it and the palea. The essential organs in the floret are exposed to the environment and subsequently the anthers dehisce releasing pollen. The pollen grains are dropped on the stigmatic branches, thus effecting self-pollination. Following pollination, the floret closes because of the collapsing of lodicules. The pollen on the stigma germinates after the floret has closed. Anthesis, both in the field and in the growth cabinet, shows a daily rhythm and occurs in the afternoon. This rhythmic floret opening seems to be temperature sensitive. The ambient temperature range for anthesis in the field is 25–28 °C. The wild oat is primarily a chasmogamous species and enforced cleistogamy in the florets can be induced experimentally.

Variation Within Pure Lines of Wild Oats (Avena fatua) in Relation to Temperature of Development

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Stephen W. Adkins ◽  
Mary Loewen ◽  
Stephen J. Symons
Keyword(s):  
Low Temperatures ◽  
Development Time ◽  
Dry Weight ◽  
Morphological Characters ◽  
Avena Fatua ◽  
Wild Oat ◽  
Plant Seed ◽  
Wild Oats ◽  
Pure Lines ◽  
Seed Water Content

Plants of dormant and nondormant wild oat (Avena fatuaL. # AVEFA) lines were grown under temperatures of 15, 20, and 25 C. A number of physiological and morphological characters in the plants and seed of both lines were influenced by temperature. Duration of dormancy in the progeny seed increased in both lines that had experienced low temperatures (15 C) during development, and decreased in seed of both lines that had experienced high temperatures (25 C) during development. High, compared to low, temperatures of development decreased plant height, vegetative and seed development time, seed numbers per plant, seed dry weight, and seed water content.

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.

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