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

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.

1979 ◽  
Vol 57 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Ramma Sawhney ◽  
J. M. Naylor

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.


1988 ◽  
Vol 66 (4) ◽  
pp. 635-641 ◽  
Author(s):  
S. Jana ◽  
M. K. Upadhyaya ◽  
S. N. Acharya

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.


Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Stephen W. Adkins ◽  
Mary Loewen ◽  
Stephen J. Symons

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.


Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 859-864 ◽  
Author(s):  
Stephen W. Adkins ◽  
Mary Loewen ◽  
Stephen J. Symons

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.


1982 ◽  
Vol 60 (7) ◽  
pp. 1142-1147 ◽  
Author(s):  
Mahesh K. Upadhyaya ◽  
James M. Naylor ◽  
Graham M. Simpson

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.


1986 ◽  
Vol 64 (9) ◽  
pp. 1910-1915 ◽  
Author(s):  
Ramma Sawhney ◽  
Andrew I. Hsiao ◽  
William A. Quick

Freshly harvested seeds of three genetically nondormant populations of wild oat (Avena fatua L.) germinated readily in the dark at optimum temperatures. Direct or diffused light caused germination inhibition in seeds of all these populations. This light-induced germination inhibition was intensity dependent; the higher the light intensity, the greater the inhibition. Germination inhibition by light was accentuated by higher incubation temperatures, indicating an interaction between these two factors on the induction of secondary seed dormancy in genetically nondormant populations. This interaction may be of adaptive significance to the survival of nondormant populations, and reconciles some apparently conflicting reports in the literature.


Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 215-219 ◽  
Author(s):  
Henri Darmency ◽  
Catherine Aujas

Three wild oats phenotypes were grown in wheat stands sown at different dates in greenhouse and field trials. Wild oats growth and seed output, and their effects on wheat biomass were not different among phenotypes when wild oats emerged 2 wk after the wheat. In experiments in which wild oats were planted in germinated wheat, one phenotype was shorter, weighed less, and produced fewer seed than the other phenotypes. Another phenotype reduced wheat biomass more than the other phenotypes. Vernalization increased vegetative growth and reduced spikelet production of one phenotype, but had no effect on its competitiveness with wheat.


Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 476-480 ◽  
Author(s):  
Robert W. Neidermyer ◽  
John D. Nalewaja

The response of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.) to barban (4-chloro-2-butynyl-m-chlorocarbanilate) was studied as influenced by plant morphology and air temperature after application. Growth of wheat and wild oat seedlings was reduced by barban at 0.3 μg and 0.6 μg applied to the first node, respectively. Barban application to the base and midpoint of the first leaf blade required a lower dose to reduce wild oat growth than wheat growth. Increased tillering occurred from barban injury to the main culm in wheat. Wheat and wild oat susceptibility to barban increased as the post-treatment temperature decreased from 32 to 10 C. Barban selectivity for wild oats in wheat was greater at 27 and 21 C than at 16 and 10 C.


Author(s):  
David M Hudson

Abstract Freshwater crustaceans are distributed throughout the montane and lowland areas of Colombia, and are therefore a useful indicator group for how aquatic species will respond to climate change. As such, metabolic determination of physiological performance was evaluated for the Colombian pseudothelphusid crab, Neostrengeria macropa (H. Milne Edwards, 1853), over a temperature range inclusive of current temperatures and those predicted by future scenarios in the plateau around the city of Bogotá, namely from 8 °C to 30 °C. The performance results mostly aligned with previous exploratory behavioral determination of the ideal temperature range in the same species, although the metabolism increased at the highest temperature treatments, a point when exploratory behavior declined. These results indicate that this species of montane crab behaviorally compensates for increased thermal stress by decreasing its physical activity, which could have negative predator-prey consequences with changes to community structure as different species undergo climate-mediated geographic range shifts in the region. As this species is endemic to the plateau surrounding Bogotá, it also experiences a number of other stressors to its survival, including infrastructure development and invasive species.


1979 ◽  
Vol 57 (15) ◽  
pp. 1663-1667 ◽  
Author(s):  
S. Jana ◽  
S. N. Acharya ◽  
J. M. Naylor

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.


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