The pattern of flavan-3-ols in relation to scab resistance of apple cultivars

1990 ◽  
Vol 65 (5) ◽  
pp. 511-517 ◽  
Author(s):  
D. Treutter ◽  
W. Feucht
2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 600-603
Author(s):  
B. Gelvonauskis ◽  
D. Gelvonauskienė

Apple cultivars were crossed according to the half-diallel and topcross mating design. Apple scab resistance of seedlings was estimated by using a 0–5 scale: 0 – no infection on leaves, 5 – more than 75% of leaf area infected. Percentage of scab resistant seedlings in crosses involving cultivars Prima varied from 35.8% to 67.6%, involving cultivars Florina and Arbat – 51.9–59.5% and 53.5–72.5%, respectively. Significant differences for resistance to scab were found among the crosses. Both general combining ability (GCA) and specific combining ability (SCA) were highly significant. The significance of GCA for scab resistance shows that genetic variability exists for this trait and selection should result in genetic progress, because the mean square for GCA was larger than that calculated for SCA. Therefore, selection of parents on its phenotype should be effective for development of resistant apple cultivars. The significant SCA estimates indicate that a large number of resistant seedlings from particular crosses should be selected.


Author(s):  
Atifa Rasool ◽  
K. M. Bhat ◽  
H. U. Rehman ◽  
M. A. Mir ◽  
Shafia Zaffar ◽  
...  

The present investigation entitled “Allelic diversity in apple germplasm for fruit quality and scab resistance using SSR markers” was conducted in division of plant biotechnology, SKUAST-K, Shalimar during the year 2018. In the present study, four SSR markers namely Md-ACS-1, Md-ACO-1, ALO-7 and AM-19 were used for screening of 40 apple cultivars presently under cultivation in SKUAST-K for quality and scab resistance. The results revealed that out of 40 cultivars evaluated, 3 were found homozygous (ACS-1-2/2), 17 were heterozygous (ACS-1-1/2) and 10 were homozygous (ACS-1-1/1), while as no amplification of ACS-1 was found for 10 cultivars. Similarly, for Md-ACO-1, 3 cultivars were found homozygous, 35 as heterozygous and 2 did not show any amplification. As far as presence of Vf gene conferring resistance against scab disease, ALO-7 amplified at 820bp and 570bp alleles, 570 bp fragment was observed in resistant genotypes and was absent in susceptible genotypes, while the 820 amplicon was observed in both resistant and susceptible genotypes. The markers AM19 led to the amplification of 520 bp fragment in few cultivars.


Author(s):  
TI Krasulia

Aim. To identify sources of several valuable economic and biological traits among new Ukrainian and foreign cultivars. Results and Discussion. The weather in the spring of 2019 and 2020 contributed to the epiphytotic development of scab, which allowed for assessment of susceptibility of new cultivars to this disease and for identification of sources of high resistance to it. There were no pathogen signs in immune cvs. Harant, Goldrush, Topaz, and William's Pride, which are carriers of the scab resistance oligogen (Vf). No cultivars that would be consistently highly-resistant to this disease in the field have been found. The creation of cultivars with a columnar crown remains a promising trend in breeding. Cv. Ruslan is a columnarity source. As to fruit yield, the leaders were Elise, Geneva Early, Goldrush, Honeycrisp, Pilot, and Topaz. Cvs. Harant, Ruslan, Elise, William's Pride gave stable fruit yields. Cvs. Kakhovske, Alionushkino, Julia, Honeycrisp, and Topaz give yields every year. Cvs. Harant, Malakhit and Rubin are sources of large fruits. Cv. Harant is noticeable for stable expression of this trait, which makes it a reference of large fruits. Mid-sized apples are considered the most optimal for selling. The sources of this trait are cvs. Ruslan, Elise, Honeycrisp, Szampion Arno, and Topaz. Most of the studied cultivars have round or flat-round fruits. Kakhovske apples are distinguished by their unordinary oval (sinapoid) shape. Sources of several features that determine highly-attractive appearance of their fruits have been distinguished. These are cvs. Harant, Malakhit, Ruslan, Elise, Geneva Early, Honeycrisp, Rubin, and William's Pride. Apples of cvs. Kakhovske, Elise, Honeycrisp, Rubin, and William's Pride are characterized by excellent palatability. Cultivars that are sources of several valuable economic and biological traits have been selected. Conclusions. Modern apple cultivars are starting material for creating new cultivars that will meet the future requirements. Cvs. Harant, Ruslan, Elise, Honeycrisp, Topaz, and William's Pride are sources of the maximum number of selectively valuable traits. By crossing them with cvs. Kakhovske, Malakhit, Alionushkino, Geneva Early, Goldrush, Julia, Pilot, and Rubin, it is possible to obtain genotypes with various ripening periods, which would combine immunity to scab, compact crown, high and stable yield, and high quality fruits.


2004 ◽  
pp. 221-224 ◽  
Author(s):  
H. Kemp ◽  
M.P. van der Maas ◽  
R.E. Voorrips ◽  
R. Groenwold ◽  
W.E. van de Weg

2020 ◽  
pp. 49-54
Author(s):  
I. Király ◽  
V. Mihálka ◽  
A. Hüvely ◽  
J. Pető ◽  
A. Palkovics ◽  
...  

2020 ◽  
Vol 56 (No. 4) ◽  
pp. 165-169
Author(s):  
Lefkothea Karapetsi ◽  
Irini Nianiou-Obeidat ◽  
Antonios Zambounis ◽  
Maslin Osathanunkul ◽  
Panagiotis Madesis

Apple scab caused by Venturia inaequalis has the most destructive effects among other phytopathogens in apple crops all over the world. The integration of resistance genes from local and domestic cultivars is a prerequisite for the efficient control of this disease and is a main target in efficient breeding approaches. Across Greece, many domestic apple cultivars are reported without deep knowledge about the presence and diversity of scab resistance genes. In this study, the presence of five resistance genes (Rvi2, Rvi4, Rvi6, Rvi8 and Rvi11) was evaluated across twenty local and domestic apple genotypes, employing twelve molecular markers closely linked to known apple scab resistance loci. Significant differences and polymorphisms among the tested cultivars were detected suggesting that some of them carry a sufficient number of resistance genes. This observed genetic diversity could be exploited in ongoing breeding approaches as a natural source of polygenic resistance against apple scab.


2015 ◽  
Vol 35 (3) ◽  
Author(s):  
Juliane Würdig ◽  
Henryk Flachowsky ◽  
Andrea Saß ◽  
Andreas Peil ◽  
Magda-Viola Hanke

2005 ◽  
Vol 11 (3) ◽  
Author(s):  
M. Tóth ◽  
P. Gracza

Anatomic studies have been performed on the leaf blade, petiole and annual shoot on six apple cultivars by means of scanning electron as well as light microscope. Four of the cultivars examined are resistant to scab (Florina, Freedom, MR-10, MR-11), whereas two of them are susceptible (Jonathan and Idared). Preliminary results suggest that differences in the width of cross sections of leaf blades, in hairyness, in the shape and size of epidermal cells, moreover, in the cross sections of petioles and shoots are considerable. Some of the anatomical properties seem to be correlated with scab resistance or susceptility of the respective cultivars. Therefore, further studies extending to other cultivars may corroborate our claims to find causal relations between anatomical traits of the leaves and disease, especially scab resistance of apple cultivars.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 619a-619
Author(s):  
Hong Y. Yang ◽  
Schuyler S. Korban ◽  
Jutta Kruger ◽  
Hanna Schmidt

Apple scab, caused by Venturia inaequalis (Cke.) Wint., is the most serious disease of apple trees. Resistance to V. inaequalis, derived from the small-fruited species Malus floribunda 821, is determined by a major dominant gene Vf. Our major objective is to identify RAPD markers linked to the Vf gene. The approach in this paper is based on the introgression of the Vf gene from M. floribunda into commercial cultivars. Almost 200 random sequence decamer-primers have been used to screen a pair of bulked samples and the donor parent M. floribunda clone 821 for markers linked to the Vf gene conferring resistance to apple scab. A single primer has been identified which generated a PCR fragment, OPK16/1300, from the donor parent M. floribunda clone 821 and the scab-resistant selections/cultivars bulk, but not from the scab-susceptible recurrent parent bulk. Co-segregation analysis using a segregating apple progeny and polymorphism analysis of individual scab-resistant Coop selections/cultivars have confirmed that this marker is linked to the scab-resistance gene Vf. OPK16/1300 has since been cloned and sequenced. Sequence-specific primers of 25 oligonucleotides based on the marker have been synthesized and used to screen further M. floribunda clone 821, scab-susceptible apple cultivars, scab-resistant apple cultivars, and scab-resistant Coop selections. The sequence-specific primers have identified polymorphisms of OPK16/1300 based on the presence or absence of a single band.


Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2074-2081 ◽  
Author(s):  
Andrea Patocchi ◽  
Andreas Wehrli ◽  
Pierre-Henri Dubuis ◽  
Annemarie Auwerkerken ◽  
Carmen Leida ◽  
...  

Apple scab, caused by Venturia inaequalis, is a major fungal disease worldwide. Cultivation of scab-resistant cultivars would reduce the chemical footprint of apple production. However, new apple cultivars carrying durable resistances should be developed to prevent or at least slow the breakdown of resistance against races of V. inaequalis. One way to achieve durable resistance is to pyramid multiple scab resistance genes in a cultivar. The choice of the resistance genes to be combined in the pyramids should take into account the frequency of resistance breakdown and the geographical distribution of apple scab isolates able to cause such breakdowns. In order to acquire this information and to make it available to apple breeders, the VINQUEST project ( www.vinquest.ch ) was initiated in 2009. Ten years after launching this project, 24 partners from 14 countries regularly contribute data. From 2009 to 2018, nearly 9,000 data points have been collected. This information has been used to identify the most promising apple scab resistance genes for developing cultivars with durable resistance, which to date are: Rvi5, Rvi11, Rvi12, Rvi14, and Rvi15. As expected, Rvi1, together with Rvi3 and Rvi8, were often overcome, and have little value for scab resistance breeding. Rvi10 may also belong to this group. On the other hand, Rvi2, Rvi4, Rvi6, Rvi7, Rvi9, and Rvi13 are still useful for breeding, but their use is recommended only in extended pyramids of ≥3 resistance genes.


Sign in / Sign up

Export Citation Format

Share Document