Author: Mary Louise Straley
Publisher:
ISBN:
Category : Phytopathogenic fungi
Languages : en
Pages : 198

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Book Description

Author: Willi Wicki
Publisher:
ISBN:
Category :
Languages : en
Pages : 103

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Book Description

Author: Jose Mauricio Fernandes
Publisher:
ISBN:
Category : Seed pathology
Languages : en
Pages : 254

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Book Description
Glume blotch of wheat, a disease incited by Septoria nodorum (=Leptosphaeria nodorum), was monitored through a succession of surveys during the period 1982-84 in eastern Washington . Findings revealed that infection in wheat occurs soon after seeddling emergence . Infection levels, varying upward of 70% in one of the two years, remained consistently high from November to March, declined somewehat in April-May and dropped dramatically in late May and June . It is speculated that such a decline is attributable to progressively fewer number of rainy days, lower relative humidities, shorter dew periods and elevating temperatures as the spring seasion advances . The viability of conidia of Septoria nodorum exposed on plastic strip underwent a corresponding decline with the advent of warmer, drier weather. The source of inoculum associated with the onset of the disease was linked to the presence of spore bearing pycnidia on debris of the previous wheat crop . The perfect stage of the fungus was never found on wheat or graminicolous hosts around and within wheat fields. Glume blotch effects on kernel weight of wheat was highly correlated with nodal infection . Substantial yield reduction ocurred when disease was imposed at the flowerig stage .According to criteria established by studying the relationship of organ infection and reduction in kernel weight it seemed unlikely that glume blotch is a disease of economic threat to the wheat industry in the Palouse. A new technique, involving the injection of inoculum into culms, was developed for evaluating cultivar reaction to glume blotch. A study of the survival of the fungus in hosts other than wheat indicated that downy chess (Bromus tectorum) may seerve as an effective alternative host. This host may play a role in the epidemiology of the disease in eastern Washington as well. Notwithstanding the results reported elsewhere, virulence of locally collected wheat isolates of Septoria nodorum, was not altered by ten consecutive passages through barley.

Author: Abdul Rahman Tarawali
Publisher:
ISBN:
Category :
Languages : en
Pages : 140

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Book Description

Author: Z. Eyal
Publisher: Cimmyt
ISBN:
Category : Septoria
Languages : en
Pages : 58

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Book Description

Author: Barry M. Cunfer
Publisher:
ISBN:
Category : Septoria
Languages : en
Pages : 86

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Book Description

Author: Maarten Van Ginkel
Publisher: CIMMYT
ISBN: 9706480358
Category : Grain
Languages : en
Pages : 194

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Book Description

Author: G. C. Luzzardi
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description

Author: João Carlos A. Dias
Publisher:
ISBN:
Category :
Languages : en
Pages : 118

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Book Description
Inheritance of sedling resistance to Septoria nodorum (Berk.) Berk. was studied in the cross of spring wheat, Toropi, with a hard red winter wheat, Centurk 78, at the University of Nebraska-Lincoln greenhouse, Lincoln, Nebraska. Percent necrosis per square centimeter of leaf area and number of lesions per square centimeter of leaf area were symptom parameters measured. Analyses od variance of the symptom expressions in the parents, F1, F2 and backcrosses to each parent were calculated. The genetic variation obtained though the frequency distribution for each generation and parents was studied. Heritability in the broad sense was calculated for each character studied. The heritability in the broad sense was relatively high, especially in the second test for both characters. The genetic variances of the F2 progenies were greater than the genetic variances within the parents. In order to obtain better information to support the finding of this study, the tests made with F2 plants should be followed up by head-row tests. These tests were not made in this study due to limitations of time. The lack of significant dominance effects the absence of heterosis for both symptom parameters studied in this experiment provide evidence that dominance may be lacking in loci controlling either susceptibility or resistance to Septoria nodorum in this cross. Very positive transgressive segregation for resistance or susceptibility was not evident in this research. From the results of this experiment it can be concluded that quantitative factors are involved in the inheritance of resistance to Septoria nodorum. Therefore, efficient breeding procedures which allow the accumulation of favorable genes for resistance through some recurrent selection system should be effective in the improvement of high-yielding lines highly resistant to Septoria nodorum. Since the pricipal problem in conducting recurrent selection in a self-pollinated crop is the large number of crosses necessary in the recombination phase of the selection cycle, simple seed descent methods could be used, as suggested by Brim (1966) and Compton (1968).

Author: Susan Ellen Penix
Publisher:
ISBN:
Category : Septoria nodorum
Languages : en
Pages : 144

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Book Description