A novel technique for evaluation of apple (Malus × domestica Borkh.) cultivars for susceptibility to powdery mildew

2001 ◽  
Vol 81 (2) ◽  
pp. 289-296 ◽  
Author(s):  
P. L. Sholberg ◽  
W. D. Lane ◽  
P. Haag ◽  
K. Bedford ◽  
L. Lashuk
Keyword(s):  
Powdery Mildew ◽  
Research Centre ◽  
Cultivar Resistance ◽  
Podosphaera Leucotricha ◽  
Malus Domestica Borkh ◽  
Novel Technique ◽  
Food Research ◽  
The Pacific ◽  
Apple Cultivars ◽  
Breeding Selection

A technique for the evaluation of apple cultivars for susceptibility to powdery mildew caused by Podosphaera leucotricha (Ell. & Ev.) E. S. Salmon (anamorph Oidium farinosum Cooke) was tested at the Pacific Agri-Food research Centre (PARC), Summerland, BC. Shoots of test cultivars [Braeburn, Creston, Elstar, Empire, Fuji strain BC2, Gala strain Royal, Jonagold, McIntosh, Delicious red strain Bisbee, Shamrock, Silken, Sunrise, and one breeding selection (11w-17-85)], approximately 6 cm in length, were grafted on to branches of mature Jonagold trees in the spring and evaluated in the summer of the same year and in subsequent years after growth on the host tree. Incidence and severity of powdery mildew were evaluated in 1994, 1995, 1997, and 1998. They were not evaluated in 1996 because approximately half the grafts from the previous year did not grow and had to be replaced. The highest incidence of powdery mildew averaged 84% for Gala, compared with only 15% for Bisbee Delicious with the lowest incidence. Gala had the highest number of P. leucotricha conidia per cm2 of leaf area (4.9 × 104) compared to Bisbee Delicious (1.2 × 104). Some of the grafted cultivars were also evaluated for primary powdery mildew and fruit russetting in 1998 after the growth for three seasons. Jonagold had the highest numbers of primary infections and russetted fruit. Key words: Podosphaera leucotricha, breeding, cultivar resistance, pest management

scholarly journals Apple powdery mildew caused by Podosphaera leucotricha: some aspects of disease management

2014 ◽  
Vol 20 (1-2) ◽  
Author(s):  
I. J. Holb
Keyword(s):  
Biological Control ◽  
Disease Management ◽  
Powdery Mildew ◽  
Chemical Control ◽  
Apple Cultivar ◽  
Apple Orchards ◽  
Cultivar Resistance ◽  
Podosphaera Leucotricha ◽  
Control Options ◽  
Apple Cultivars

Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. This review focuses on the control of apple powdery mildew. The first part of the study provides details of novel aspects of non-chemical control approaches, including agronomic measures, mechanical and biological control options as well as essential features of apple cultivar resistance. After this, developments in chemical control options are described sperately for integrated and organic apple orchards.

Screening sweet cherry cultivars from the Pacific Agri-Food Research Centre Summerland breeding program for resistance to brown rot (Monilinia fructicola)

2008 ◽  
Vol 88 (4) ◽  
pp. 747-752 ◽  
Author(s):  
Frank Kappeland ◽  
Peter L Sholberg
Keyword(s):  
Prunus Avium ◽  
Brown Rot ◽  
Breeding Program ◽  
Research Centre ◽  
Monilinia Fructicola ◽  
Conidial Suspension ◽  
Food Research ◽  
The Pacific ◽  
Sweet Cherries ◽  
Sweet Cherry Cultivars

Recently released cultivars and advanced selections of sweet cherries (Prunus avium L.) from the breeding program at the Pacific Agri-Food Research Centre at Summerland, British Columbia, were screened for resistance to brown rot [Monilinia fructicola (Wint.)]. From 2000 to 2003 a range of sweet cherries were inoculated by spraying with a conidial suspension of 1 × 104 colony-forming units per mL of Monilinia fructicola, placed in a growth chamber at 13°C and rated for rot at 8 and 11 d after inoculation. The response of cultivars or selections varied from year to year. In 2000, 10 of 14 cultivars had disease incidences of over 50% by day 8, whereas, in 2002, only 2 of 19 cultivars had disease incidences greater than 50%. Staccato™, Stardust and Sweetheart were in the least susceptible category, that is, the percent rot infection was significantly less than the mean of all genotypes in 2 of the 4 yr. Santina, Skeena, and 13N-07-32 were in the least susceptible category in 1 of 4 yr. The level of resistance to brown rot was not very high. For the least susceptible cultivars such as Staccato™, Stardust, or Sweetheart, the level of resistance was not high enough to grow the crop without fungicide applications. Key words: Prunus avium, resistance, inoculation

Chilliwack-VR orchardgrass

2006 ◽  
Vol 86 (1) ◽  
pp. 173-175 ◽  
Author(s):  
S. Bittman ◽  
S. N. Acharya ◽  
D. E. Hunt
Keyword(s):  
Dactylis Glomerata ◽  
Mottle Virus ◽  
Research Centre ◽  
Temperate Climate ◽  
Food Research ◽  
The Pacific ◽  
Southern Alberta ◽  
Dactylis Glomerata L ◽  
Cocksfoot Mottle Virus ◽  
Better Than

Chilliwack-VR is a medium-maturing orchardgrass (Dactylis glomerata L.) population with high levels of resistance to Cocksfoot Mottle Virus (CfMV) suited to silage and hay production in regions with a moderate temperate climate. The population was developed at the Pacific Agri-Food Research Centre (PARC), Agriculture and Agri-Food Canada (AAFC), Agassiz, BC, in collaboration with AAFC Research Centre, Lethbridge, AB. In BC trials, Chilliwack-VR yielded 5% more than the check cultivar Potomac without inoculation with CfMV and 23% better than the check when inoculated with the virus. In a southern Alberta trial, Chilliwack-VR survived for 3 yr and yielded as much biomass as a winterhardy check cultivar, Kay. Key words: Orchardgrass, Cocksfoot Mottle Virus resistance, Dactylis glomerata

scholarly journals Pyramiding resistance genes and widening the genetic base of the apple (Malus × domestica Borkh.) crop

Italus Hortus ◽  
2021 ◽  
Vol 28 (1) ◽  
pp. 32
Author(s):  
Raffaele Testolin ◽  
Luigi Falginella ◽  
Alberto De Carli ◽  
Gloria De Mori ◽  
Guido Cipriani
Keyword(s):  
Molecular Markers ◽  
Disease Resistance ◽  
Powdery Mildew ◽  
Resistance Genes ◽  
Field Observations ◽  
Vf Gene ◽  
Malus Domestica Borkh ◽  
Genetic Base ◽  
Apple Cultivars ◽  
New Cultivars

Apple breeding is active worldwide and yet the apple crop is in a precarious state as it relies on few dominant cultivars and only the Rvi6 (formerly Vf) gene, that confers resistance to scab, has been extensively exploited in the cultivars entered the market in recent years. However, there are some 20 disease resistance genes described in apple and the apple germplasm includes thousands of accessions in the repositories. In this paper, a breeding programme is described, whereby 36 genotypes, including ancient and contemporary apple cultivars, were crossed to produce a new set of selections that combine extensive genetic resources with pyramided resistance genes to several apple diseases, such as scab and powdery mildew. The 110 cross combinations carried out successfully, of the 260 initially planned, produced 7,876 offsprings, reduced to 2,969 after screening with molecular markers associated with five resistance genes. Selections with three or two resistance genes and good agronomic characteristics were kept for further field observations with the aims of creating new cultivars for the market and new parents for future breeding projects

Cheam-VR orchardgrass

2006 ◽  
Vol 86 (1) ◽  
pp. 169-171
Author(s):  
S. Bittman ◽  
S. N. Acharya ◽  
D. E. Hunt
Keyword(s):  
Dactylis Glomerata ◽  
Mottle Virus ◽  
Research Centre ◽  
Temperate Climate ◽  
Food Research ◽  
The Pacific ◽  
Southern Alberta ◽  
Dactylis Glomerata L ◽  
Cocksfoot Mottle Virus ◽  
Better Than

Cheam-VR is an early-maturing orchardgrass (Dactylis glomerata L.) cultivar with high levels of resistance to Cocksfoot Mottle Virus (CfMV) suited to silage and hay production in regions with moderate temperate climate. The population was developed at the Pacific Agri-Food Research Centre (PARC), Agriculture and Agri-Food Canada (AAFC), Agassiz, BC, in collaboration with AAFC Research Centre, Lethbridge, AB. In BC trials, Cheam-VR yielded 6% better than the check cultivar Potomac without inoculation with CfMV and 15% more than the check when inoculated with the virus. In a southern Alberta trial, Cheam-VR survived for 3 yr and yielded 6% more than a winterhardy check cultivar, Kay. Key words: Orchardgrass, Cocksfoot Mottle Virus resistance, Dactylis glomerata

scholarly journals Development and ultrastructure observations of secondary hyphae of Podosphaera leucotricha on apple cultivars of varying susceptibility to powdery mildew

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 425-428
Author(s):  
E. Rakhimova
Keyword(s):  
Electron Microscopy ◽  
Powdery Mildew ◽  
Light And Electron Microscopy ◽  
Dense Material ◽  
Podosphaera Leucotricha ◽  
Powdery Mildew Fungus ◽  
Full Complement ◽  
Apple Cultivars ◽  
Host Parasite

The development and ultrastructure feature of secondary hyphae of Podosphaera leucotricha were studied using light and electron microscopy. The percentage of development and length of secondary hyphae, differed in compatible and incompatible combinations. In compatible host-parasite combinations, hyphal cells of powdery mildew fungus contained a full complement of fungal organelles. There were differences of hyphal ultrastructure in compatible and incompatible host-parasite combinations, the main one was the appearance of dense material inside the nucleus, in the cytoplasm, and a few mitochondria.

Haida-VR orchardgrass

2006 ◽  
Vol 86 (1) ◽  
pp. 177-179
Author(s):  
S. Bittman ◽  
S. N. Acharya ◽  
D. E. Hunt
Keyword(s):  
Dactylis Glomerata ◽  
Mottle Virus ◽  
Research Centre ◽  
Temperate Climate ◽  
Food Research ◽  
The Pacific ◽  
Southern Alberta ◽  
Dactylis Glomerata L ◽  
Cocksfoot Mottle Virus ◽  
Better Than

Haida-VR is a latematuring orchardgrass (Dactylis glomerata L.) cultivar with high levels of resistance to Cocksfoot Mottle Virus (CfMV) suited to silage and hay production in regions with moderate, temperate climate. The cultivar was developed at the Pacific Agri-Food Research Centre (PARC), Agriculture and Agri-Food Canada (AAFC), Agassiz, British Columbia (BC) in collaboration with AAFC Research Centre, Lethbridge, Alberta. In BC trials, Haida-VR yielded 3% more than the check cultivar Potomac without inoculation with CfMV and 21% better than the check when inoculated with the virus. In a southern Alberta trial, Haida-VR survived for 3 yr and yielded 3% better than a winterhardy check cultivar, Kay. Key words: Orchardgrass, Cocksfoot Mottle Virus resistance, Dactylis glomerata

Susceptibility of apple cultivars to apple scab and powdery mildew in Victoria, Australia

1998 ◽  
Vol 38 (6) ◽  
pp. 625 ◽  
Author(s):  
W. S. Washington ◽  
O. N. Villalta ◽  
J. Ingram ◽  
D. Bardon
Keyword(s):  
Powdery Mildew ◽  
Venturia Inaequalis ◽  
Natural Infection ◽  
Apple Scab ◽  
Podosphaera Leucotricha ◽  
Commercial Cultivars ◽  
Apple Cultivars ◽  
High Level

Summary. Twenty apple cultivars were assessed over 3 seasons for their susceptibility to natural infection with scab (caused by Venturia inaequalis) and powdery mildew (caused by Podosphaera leucotricha). It was evident that a number of important commercial cultivars are highly susceptible to leaf scab (average incidence of leaf scab: Pink Lady, 40.2% of leaves; Lady William, 37.1%; Braeburn, 20.0%; and New Jonagold, 18.7%) and powdery mildew (average incidence of leaf mildew: New Jonagold, 23.0%; Pink Lady, 17.8%). There was a high level of resistance to leaf scab in the cultivars Florina-Quérina, Redfree and Jonafree (all less than 1% incidence on leaves) and to powdery mildew in the cultivar Earlidel (no infection observed). The cultivars Jonathan, Bonza and Red Elstar showed a useful level of resistance to scab (average incidence of leaf scab between 1.6 and 3.2%), while the cultivars Red Fuji, HiEarly and Redfree all showed some resistance to powdery mildew (average incidence of mildew between 2.6 and 5.9%). Observations made on the low and variable numbers of fruit produced by some trees in their third year after planting showed that Pink Lady and Lady William were highly susceptible to fruit scab (67.6 or 57.6% scabbed fruit respectively). Twig infection by scab was also observed on shoots of the current season’s growth of Pink Lady.

scholarly journals Field susceptibility of 13 scab-resistant apple cultivars to apple powdery mildew [Podosphaera leucotricha (Ell. et Ev.) Salmon]

2013 ◽  
Vol 40 (1-2) ◽  
pp. 87-98
Author(s):  
Zbigniew Borecki
Keyword(s):  
Powdery Mildew ◽  
Chemical Control ◽  
Podosphaera Leucotricha ◽  
Apple Trees ◽  
Complete Field ◽  
Apple Cultivars ◽  
Disease Pressure ◽  
Moderate Susceptibility

Field susceptibility of 13 scab-resistant apple cultivars to apple powdery mildew was evaluated in 1983-1986. Four groups of susceptibility were distinguished. None of the 13 tested scab-resistant apple trees exhibited complete field immunity to apple powdery mildew. Two cultivars, 'Prima' and 'Primula', were practically resistant. 'Liberty' and two numbered selections, NY-140-9 and NY-158-2, belonged to the group of lower susceptibility. Moderate susceptibility was shown by: 'Novamac', 'Freedom', 'Gavin', 'Prima' and 'Florina'. The group of apple trees most susceptible to <i>Podosphaera leucotricha</i> included: 'Macfree', 'Priscilla' and 'Nova Easygro'. It is not necessary to use chemical sprays to control powdery mildew on 'Prima' and 'Primula'. A reduced spraying program may be recommended only under high disease pressure on less susceptible apple cultivars. A regular spray schedule is needed on moderately susceptible apple trees, but improved chemical control is necessary on the most susceptible ones.

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