scholarly journals Heritability of Fruit Rot Resistance in American Cranberry

2015 ◽  
Vol 140 (3) ◽  
pp. 233-242 ◽  
Author(s):  
Jennifer Johnson-Cicalese ◽  
James J. Polashock ◽  
Josh A. Honig ◽  
Jennifer Vaiciunas ◽  
Daniel L. Ward ◽  
...  

Fruit rot is the primary threat to cranberry (Vaccinium macrocarpon) production in the northeastern United States, and increasingly in other growing regions. Efficacy of chemical control is variable because the disease is caused by a complex of pathogenic fungi. In addition, cranberries are often grown in environmentally sensitive areas, placing restrictions on chemical control measures. Thus, a major focus of the cranberry breeding program is to develop cultivars with improved fruit rot resistance (FRR). Several genetically diverse sources of FRR have been identified in our germplasm collection. However, the most resistant accessions lack one or more attributes; e.g., productivity, required for commercial acceptance. These resistant accessions were used in crosses with elite high-yielding selections and in 2009, 1624 progeny from 50 crosses were planted in 2.3-m2 field plots. During 2011–13, under field conditions with very limited fungicide management, disease pressure was severe, allowing evaluation for FRR. Plots were rated on a 1–5 scale for incidence of fruit rot (where 1 = 0% to 20% rot and 5 = 81% to 100% rotted fruit), and rotted fruit counts were made from selected plots to validate the ratings. There was a good correlation in the ratings between years (2011 vs. 2012: r = 0.59, P < 0.0001; 2011 vs. 2013: r = 0.50, P < 0.0001; 2012 vs. 2013: r = 0.62, P < 0.0001), and between rot ratings and percent rotted fruit (r = 0.90, P < 0.0001). Significant differences were found between and within families for FRR. High heritability estimates (h2 = 0.81) were obtained with midparent-offspring regression of mean fruit rot ratings, indicating additive genetic variance for FRR. Introgression of FRR into higher yielding genetic backgrounds was also accomplished, as some progeny exhibiting high FRR also had commercially viable yield (>300 g/0.09 m2), as well as good berry size and color. Selections are being further evaluated for potential cultivar release.

2020 ◽  
Vol 5 (1) ◽  
pp. 404-440 ◽  
Author(s):  
Mehrdad Alizadeh ◽  
Yalda Vasebi ◽  
Naser Safaie

AbstractThe purpose of this article was to give a comprehensive review of the published research works on biological control of different fungal, bacterial, and nematode plant diseases in Iran from 1992 to 2018. Plant pathogens cause economical loss in many agricultural products in Iran. In an attempt to prevent these serious losses, chemical control measures have usually been applied to reduce diseases in farms, gardens, and greenhouses. In recent decades, using the biological control against plant diseases has been considered as a beneficial and alternative method to chemical control due to its potential in integrated plant disease management as well as the increasing yield in an eco-friendly manner. Based on the reported studies, various species of Trichoderma, Pseudomonas, and Bacillus were the most common biocontrol agents with the ability to control the wide range of plant pathogens in Iran from lab to the greenhouse and field conditions.


2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Zahaed Evangelista-Martínez ◽  
Erika Anahí Contreras-Leal ◽  
Luis Fernando Corona-Pedraza ◽  
Élida Gastélum-Martínez

Abstract Background Fungi are one of the microorganisms that cause most damage to fruits worldwide, affecting their quality and consumption. Chemical controls with pesticides are used to diminish postharvest losses of fruits. However, biological control with microorganisms or natural compounds is an increasing alternative to protect fruits and vegetables. In this study, the antifungal effect of Streptomyces sp. CACIS-1.5CA on phytopathogenic fungi that cause postharvest tropical fruit rot was investigated. Main body Antagonistic activity was evaluated in vitro by the dual confrontation over fungal isolates obtained from grape, mango, tomato, habanero pepper, papaya, sweet orange, and banana. The results showed that antagonistic activity of the isolate CACIS-1.5CA was similar to the commercial strain Streptomyces lydicus WYEC 108 against the pathogenic fungi Colletotrichum sp., Alternaria sp., Aspergillus sp., Botrytis sp., Rhizoctonia sp., and Rhizopus sp. with percentages ranging from 30 to 63%. The bioactive extract obtained from CACIS-1.5 showed a strong inhibition of fungal spore germination, with percentages ranging from 92 to 100%. Morphological effects as irregular membrane border, deformation, shrinkage, and collapsed conidia were observed on the conidia. Molecularly, the biosynthetic clusters of genes for the polyketide synthase (PKS) type I, PKS type II, and NRPS were detected in the genome of Streptomyces sp. CACIS-1.5CA. Conclusions This study presented a novel Streptomyces strain as a natural alternative to the use of synthetic fungicides or other commercial products having antagonistic microorganisms that were used in the postharvest control of phytopathogenic fungi affecting fruits.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kamel Kamal Sabet ◽  
Magdy Mohamed Saber ◽  
Mohamed Adel-Aziz El-Naggar ◽  
Nehal Samy El-Mougy ◽  
Hatem Mohamed El-Deeb ◽  
...  

Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens.


2016 ◽  
Vol 44 (1) ◽  
pp. 60-66
Author(s):  
Xuehua ZHANG ◽  
Linling LI ◽  
Shuiyuan CHENG ◽  
Hua CHENG

Fungal diseases of plants continue to contribute to heavy crop losses in spite of the best control efforts of plant pathologists. Breeding for disease-resistant varieties and the application of synthetic chemical fungicides are the most widely accepted approaches in plant disease management. CMN1308 strain of Bacillus amyloliquefaciens was isolated from healthy Chinese chestnut fruit, which has antibiosis and induced resistance to the prevention mechanism of pathogenic bacterium after picking. In order to evaluate the antibiosis mechanism, CMN1308 was fostered with the method of confront culture. The antimicrobial components were also isolated from the culture of CMN1308, and their stability and antimicrobial activity was tested under different treatments such as temperature, pH and UV. The results showed that CMN1308 displays advantages in regard to spatial competition against the major pathogens of chestnut, Rhizopus stolonifer, Fusarium solani, Stachybotrys chartarum, Cryphonectria parasitica, Lasiodiplodia theobromae, Penicillium expansum and Aspergillus niger. Among this, CMN1308 had the best antimicrobial activity against P. expansum, with the inhibition zone diameter of 27.1 mm. The antimicrobial material isolated from CMN1308 culture showed a strong inhibition to the growth of P. expansum hyphal and also had a good stability to high temperature, alkali media and UV, but was sensitive to acidic conditions. Furthermore, CMN1308 increased the peroxidase, polyphenol oxidase activity and reduced the MDA content in chestnuts after infecting by pathogenic fungi. Thus, producing antibiotic compounds and inducible resistance are the main factors that may explain the antibacterial mechanism of CMN1308 on chestnut pathogenic. The results of this study might help to optimize the practical use of CMN1308 in the biological control of chestnut rot or other fruit rot infected by pathogenic fungi.


2021 ◽  
Vol 45 ◽  
Author(s):  
Tarcísio Marcos Macedo Mota Filho ◽  
Luis Eduardo Pontes Stefanelli ◽  
Roberto da Silva Camargo ◽  
Carlos Alberto Oliveira de Matos ◽  
Luiz Carlos Forti

ABSTRACT Chemical control using toxic baits containing the active ingredient sulfluramid at 0.3% (w/w) is the main method for controlling leaf-cutting ants of the genera Atta and Acromyrmex. However, since 2009, when sulfluramid was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants, there has been an intense search for new methods that are efficient in controlling these insects. Among said new methods, biological control using pathogenic fungi has shown promising results in laboratory conditions. The objective of this study, given the context presented, was to assess the potential of the fungi Beauveria bassiana and Trichoderma harzianum in controlling Atta sexdens. Colonies of A. sexdens were exposed to the fungi by means of formulated baits provided in a foraging chamber, or of suspensions sprayed on the fungus garden, and had their behavioral changes recorded for 21 days. For both formulations, concentrations of 10 and 20% (w/w) of the fungi being studied were used. The results allowed concluding that baits containing 10 and 20% (w/w) of the fungi B. bassiana and T. harzianum were not efficient in controlling colonies of A sexdens. On the other hand, spraying suspensions of 20% (w/w) of B. bassiana and 10% and 20% (w/w) of T. harzianum was efficient and resulted in 100% mortality of the colonies 11, 9 and 7 days after application, respectively. These findings indicate that the fungi B. bassiana and T. harzianum are promising as agents for the control of A. sexdens colonies, when sprayed on the fungus garden, although there are still some challenges as to their use related to the development of technologies for the application of the pathogen.


2021 ◽  
Vol 44 (02) ◽  
Author(s):  
NGUYEN NGOC AN ◽  
HUA HUYNH MINH THAO ◽  
HO NGUYEN HOANG YEN ◽  
NGUYEN THI DIEU HANH ◽  
NGUYEN LE HIEN HOA ◽  
...  

Dragon fruit or pitahaya (Hylocereus spp.) are famous for their nutrient-rich favourable taste, which brings high economic value to subtropical and tropical countries. However, dragon fruit cultivation all over the world is threatened by fungal pathogens and among them, Neoscytalidium dimidiatum has recently been shown to be responsible for stem canker and fruit rot which cause big economic losses. In order to find an environmentally friendly way to control this pathogen, five out of sixty-nine bacterial isolates used in a screening test for antifungal activity were selected. All five strains appeared to be aerobic Gram positive spore forming bacteria suggesting that they all belong to the Bacillus genus. Cell-free culture supernatants of these strains were found to strongly inhibit both fungal spore germination and mycelia growth in vitro for at least 5 days. The strain D19 which possessed the highest antagonistic effect was further identified to be Bacillus amyloliquefaciens, a well-known species shown to have antifungal effect against several other pathogenic fungi. Thus, the results of this study opened a new promising perspective to prevent Neoscytalidium dimidiatum infection during cultivation of dragon fruit.


Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 502-508 ◽  
Author(s):  
Sarah Brown ◽  
Steven T. Koike ◽  
Oswaldo E. Ochoa ◽  
Frank Laemmlen ◽  
Richard W. Michelmore

Lettuce downy mildew, caused by Bremia lactucae, is the most important foliar disease of lettuce in California. In recent years, there were apparent failures of fungicides containing fosetyl-aluminum (Aliette) to control downy mildew in commercial lettuce fields in California. Consequently, we characterized 134 isolates collected over 2 years from throughout the coastal growing areas of California for insensitivity to the fungicides fosetyl-aluminum and maneb, pathotype, and mating type. Tests using seedlings in controlled growth room conditions demonstrated the widespread occurrence of insensitivity to fosetyl-aluminum in California populations of B. lactucae. Fifty percent of the isolates assayed sporulated profusely in the presence of fosetyl-aluminum applied at rates twice the normal field dosage, and an additional 40% showed moderate sporulation at this rate. Fosetyl-aluminum-insensitive isolates were detected from all regions sampled. Insensitivity was also observed in multiple pathotypes. Insensitivity was not complete, however, because quantitative analysis of the number of lesions on older plants revealed that applications of fosetyl-aluminum could reduce the levels of disease by 50%. Therefore, while fosetyl-aluminum may have utility under low disease pressure in the field, other control measures are required to provide control under conditions favorable to the disease.


2009 ◽  
pp. 83-88
Author(s):  
Zhu Xiao-qing ◽  
Wang Hai-xia ◽  
Qin Ling ◽  
Liu Su-hua ◽  
Liu Zheng-ping ◽  
...  
Keyword(s):  

1956 ◽  
Vol 47 (2) ◽  
pp. 377-397 ◽  
Author(s):  
W. F. Jepson

The principal pest of sugar-cane in northern Tanganyika is the Red Cane Beetle, Cochliotis melolonthoides (Gerst.) (Melolonthidae). Descriptions of adults and larvae of Cochliotis and of allied beetles found in the same area are given.The bionomics of Cochliotis have been studied in the field over two seasons. The life-cycle is annual with adult swarming in early October and a season of maximum larval damage in July–August.The intensity of infestation and the nature of the losses are discussed, and the mortality factors which act upon Cochliotis in nature are reviewed.Cultural control measures suggested include the deferment of planting until July to October, when larval activity has waned; introduction of quick-maturing varieties, mechanically cultivated so that long ratooning can be gradually eliminated; regulation of the water table by control of irrigation, and the trial of resistant varieties. The Mauritius varieties M. 134/32 and M. 165/38 are suggested in this connection.Biological control is discussed and a review of the parasite species that might possibly be introduced is made largely from the writer's Mauritius work on Clemora smithi (Arr.).Experiments in the chemical control of Cochliotis are described and the final recommendation is the application at planting of ½ lb. per 50 ft. of furrow of a BHC powder containing 2·5 per cent, of γ BHC. This practice has been adopted by the infested estate with successful results in virgins and first ratoons.Further work is suggested on the chemical protection of second and later ratoons by surface application of BHC or aldrin.


1982 ◽  
Vol 114 (4) ◽  
pp. 363-376 ◽  
Author(s):  
M. D. Proverbs ◽  
J. R. Newton ◽  
C. J. Campbell

AbstractCodling moth, Cydia pomonella (L.), control by sterile insect release (SIR) was assessed in 320–526 ha of apples and pears in the Similkameen Valley, B.C., from 1976 to 1978. In preparation for SIR, the moth population was first reduced to low numbers by removal of neglected trees in 1972 and by chemical sprays in 1975. Sterile (35 krad) male and female moths were released in each orchard 2 or 3 times weekly from 1 May until early September. A total of 23,600 sterile moths/ha was released in 1976, 36,500 in 1977, and 31,800 in 1978. Populations of sterile (marked) and wild moths were monitored by sex pheromone traps, and damage was assessed by fruit examination at harvest. Control was very good except for a few orchards in which overwintered populations were too high to achieve adequate overflooding with sterile moths. Damage exceeded the economic threshold (0.5%) in only 1 of 86 treated orchards in 1976, in 6 of 193 orchards in 1977, and in 0 of 157 orchards in 1978. Results in 32 orchards showed that when wild populations are brought close to extinction all codling moth control measures can be omitted for 2 or more years depending on degree of orchard isolation. Omission of codling moth sprays from 1976 to 1978 did not result in any important change in population levels of other apple pests. Cost of control by SIR was ca. $225/ha per year vs. ca. $95 for chemical control.


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