A COMPARISON OF METHODS FOR ANALYZING INHERITANCE DATA FOR RESISTANCE TO RED RASPBERRY POWDERY MILDEW

1968 ◽  
Vol 10 (2) ◽  
pp. 341-350 ◽  
Author(s):  
Hugh A. Daubeny ◽  
P. B. Topham ◽  
D. L. Jennings
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Genetic Interactions ◽  
Continuous Variation ◽  
Red Raspberry ◽  
Complementary Information ◽  
Parental Resistance ◽  
Discontinuous Variation ◽  
Use Of Models ◽  
Additive Genes

The simultaneous use of models applicable to discontinuous and continuous variation for analyzing the segregation of powdery mildew resistance in red raspberry progenies gave complementary information. The analysis based on the model for discontinuous variation supported the hypothesis that segregation was controlled by two additive genes for resistance and one epistatic gene for susceptibility. This analysis gives information on the possible genotypes of the parents which facilitates predictions on the proportion of resistant seedlings expected in breeding programs.The analysis based on the model for continuous variation also indicated that inheritance was predominantly additive with significant genetic interactions. However, the estimates of parental contributions to the progenies were more widely based, because allowance was made for the effects of different gene viabilities, of modifying genes and of environmental influences on expression of the disease. Estimates of combining ability obtained from this model facilitate predictions of mean resistance of progenies.The use of each model appeared to provide a more complete assessment of parental resistance contributions than either model used alone.

Variation in maturity, stolon development and frost resistance of Glycine javanica

1966 ◽  
Vol 6 (23) ◽  
pp. 380 ◽  
Author(s):  
LA Edye ◽  
HJ Kiers
Keyword(s):  
Flowering Time ◽  
Frost Resistance ◽  
Seed Set ◽  
Flowering Period ◽  
Early Variety ◽  
South Eastern ◽  
Discontinuous Variation ◽  
Late Maturity ◽  
Maturity Type ◽  
Stolon Development

Introductions of G. javanica showed wide variation in flowering time, seed set, seed yield, stolon development, and frost resistance at Lawes in south-eastern Queensland. The discontinuous variation in flowering time of 50 introductions over 103 days at Lawes has enabled very early, early, midseason, and late maturity types to be defined. These maturity classes hold equally well when applied at 'Lansdown' in north Queensland. With the exception of C.P.I. 25336, only very early and early introductions set seed in large areas of south-eastern Queensland where frosts are experienced in June and July. C.P.I. 25336, an early variety with an extended flowering period, did not set seed before the first heavy frost on June 24, 1961. The association of maturity type, stolon development, and frost resistance with the country of origin of the introductions is mentioned and the significance of these characters in adapting G. javanica to Australian conditions is discussed.

scholarly journals DISCONTINUOUS VARIATION AND PEDIGREE CULTURE

Science ◽  
1906 ◽  
Vol 24 (613) ◽  
pp. 399-400 ◽  
Author(s):  
D. S. JORDAN
Keyword(s):  
Discontinuous Variation

Molecular and morphological variation in the Senna artemisioides complex

2000 ◽  
Vol 48 (5) ◽  
pp. 569 ◽  
Author(s):  
J. E. Holman ◽  
J. Playford
Keyword(s):  
Genetic Variation ◽  
National Park ◽  
Species Complex ◽  
Genetic Distances ◽  
Genetic Differences ◽  
A Value ◽  
Discontinuous Variation ◽  
Integrative Study ◽  
Systematic Relationships ◽  
Foliar Morphology

The Senna artemisioides species complex is characterised by extremely variable foliar morphology. This paper presents the results of an integrative study on reproductive biology, morphology and genetic variation to explore the evolutionary and systematic relationships within this species complex at Idalia National Park in central Queensland. Senna artemisioides showed discontinuous variation at both genetic and phenotypic level. At three sites, foliar morphology was discontinuous, being represented as discrete clusters. Analysis of isozyme variation indicated that many of the discrete morphological groups are distinguished by fixed genetic differences. Morphotypes were also characterised by widespread monomorphism. Most of the genetic variation was between morphotypes rather than within morphotypes. These fixed genetic differences indicate a lack of gene flow between morphotypes and therefore an absence of hybridisation. The two most distinct morphological groups (pyllodinous, pinnate) had high genetic distances of 0.5, a value beyond the usual distance between congeneric species. Forty-two percent of pairwise comparisons between other morphotypes yielded genetic distance values that were relatively high (0.21–0.42). Some phenotypically distinct morphotypes, however, showed little or no isozyme divergence. The combined evidence suggests that genetically distinct morphotypes are independent lineages originating from an ancestral sexual reproductive event that is perpetuated by apomictic reproduction.

scholarly journals On a discontinuous variation occurring in Biscutella lævigata

1898 ◽  
Vol 62 (379-387) ◽  
pp. 11-26 ◽  
Keyword(s):  
The Other ◽  
Perennial Herb ◽  
Southern Europe ◽  
Italian Alps ◽  
Alpine Regions ◽  
Discontinuous Variation ◽  
The One ◽  
Biscutella Laevigata ◽  
Cruciferous Plant

The observations recorded in this paper were made upon Biscutella Iævigata , a cruciferous plant occurring as a perennial herb in the alpine and sub-alpine regions of middle and southern Europe. It was observed by Mr. Bateson that in a valley of the Italian Alps this species exhibits two distinct forms, which exist side by side, the one hairy and the other glabrous. Plants showing various degrees of hairiness, and constituting a series of intermediate forms connecting the two extremes, were also found, but were comparatively scarce.

Mendelian Phenomena and Discontinuous Variation

1908 ◽  
Vol os-4 (1) ◽  
pp. 359-360
Author(s):  
W. J. Spillman
Keyword(s):  
Discontinuous Variation
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