\u3ci\u3eNeofusicoccum luteum\u3c/i\u3e as a Pathogen on Tejocote (\u3ci\u3eCrataegus mexicana\u3c/i\u3e)

Tejocote (Crataegus mexicana), a small pome crab-apple-like fruit, is becoming economically important in California with increasing production, so consideration of diseases that hinder the yield is important. Diseased trees of tejocote were observed in four orchards of Riverside and San Diego Counties of California. Ten symptomatic/asymptomatic samples were studied from each of the orchards. Five most frequently isolated fungi were identified on the basis of morphological characters and sequence data of the internal transcribed spacer ITS1-5.8SITS2 and partial β-tubulin gene. Three isolates were identified as Neofusicoccum luteum and two as Phomopsis sp. Pathogenicity tests were conducted by inoculating detached shoots of healthy tejocote trees. Significant lesions were observed on all shoots inoculated with the three N. luteum isolates (designated UCR1190, UCR1191, and UCR1192), but not on the shoots inoculated with other isolates or the non-inoculated controls. Results indicated that all three N. luteum isolates are aggressive pathogens on tejocote. This pathosystem should be further studied with a goal of designing appropriate disease management strategies

Association of Spores of «Phaeomoniella chlamydospora», «Phaeoacremonium inflatipes», and «Pm. aleophilum» with Grapevine Cordons in California

Esca (black measles) of grapevine has long been known to occur wherever grapes are grown. Phaeomoniella chlamydospora and two species of Phaeoacremonium, Pm. inflatipes and Pm. aleophilum, have been associated with esca and Petri grapevine decline in major production regions of California. Though present in symptomatic grapevines and capable of causing foliar symptoms of esca, Phaeomoniella chlamydospora does not cause the typical symptoms on fruit. However, trapping studies showed that spores of Pa. chlamydospora, Pm. inflatipes and Pm. aleophilum were captured throughout the year in vineyards ranging from the north California coast to the southern San Joaquin Valley. They can be considered airborne fungi capable of being water-splashed by pruning or other wounds during part of their biological cycle. Trapping of spores coincided with rainfall events for Pa. chlamydospora and Pm. inflatipes, and to a lesser degree for Pm. aleophilum. However, this last species was trapped during periods of time when rainfall did not occur and was trapped longer into the summer

Rootstock Susceptibility to «Phaeomoniella chlamydospora» and «Phaeoacremonium» spp.

Twenty healthy cuttings each were inoculated artificially with Phaeomoniella chlamydospora, Phaeoacremonium inflatipes and Phaeoacremonium aleophilum. After the formation of callus, they were planted in pots. Approximately one year after inoculation, disease occurrence was recorded as the length of brown vascular streaking from the base of plant toward the shoot tip. Discolored areas were cultured on potato dextrose agar amended with tetracycline hydrochloride (PDA-tet) and pathogens were re-isolated. Inoculation with Pa. chlamydospora showed that rootstocks 3309, 420A, 110R, 5C, Schwarzmann, St. George, and Salt Creek were least susceptible, while 99R, 39-16, Freedom, Riparia Gloire, 140Ru, 16-16 and 1103 were most susceptible. When inoculated with Pm. inflatipes, 16-16, 3309, AXR1, Salt Creek, 110R, 5C, Freedom and 140Ru were least susceptible, while 420A, St. George, 161-49, and Harmony were most susceptible. Inoculation with Pm. aleophilum showed that 1103, 420A, Harmony, and Salt Creek were least susceptible, while 110R, SO4, 39-16 and 161-49 were most susceptible. The susceptibility of the rootstocks and the occurrence of vine decline in the field in California did not appear to be well correlated because 3309, 101-14, 5C, and 110R were always most susceptible. But these rootstocks are the most widely planted, and hence the natural occurrence of the disease is probably skewed towards these rootstocks. However, since no resistance was detected in our study, even though there was a wide range of susceptibility, the degree of rootstock susceptibility may not be such an important factor in disease expression under natural conditions

Recovery of «Phaemoniella chlamydospora» and «Phaeoacremonium inflatipes» from Soil and Grapevine Tissues

Rose Bengal Chloramphenicol Agar (RBCA) appears to be a suitable media for isolating Phaeoacremonium spp. and Phaeomoniella chlamydospora from soil, spore traps and plant tissue. Using the soil-plate method, populations of these organisms were recovered from the soil and surfaces of plant tissue from many different regions of California. In addition, in a few vineyard sites these fungi were recovered from dried plant sap, which had oozed from grapevine girdling wounds and from standing water under grapevine drip systems. RBCA, along with a filtering system, is a useful tool in determining the presence of Petri disease pathogens in vineyard soils, water, and plant tissues. This research presents the first report of the recovery of Phaeoacremonium inflatipes from soil and standing water under grapevines

Neofusicoccum luteum as a pathogen on Tejocote (Crataegus mexicana)

Tejocote (Crataegus mexicana), a small pome crab-apple-like fruit, is becoming economically important in California with increasing production, so consideration of diseases that hinder the yield is important. Diseased trees of tejocote were observed in four orchards of Riverside and San Diego Counties of California. Ten symptomatic/asymptomatic samples were studied from each of the orchards. Five most frequently isolated fungi were identified on the basis of morphological characters and sequence data of the internal transcribed spacer ITS1-5.8S-ITS2 and partial β-tubulin gene. Three isolates were identified as Neofusicoccum luteum and two as Phomopsis sp. Pathogenicity tests were conducted by inoculating detached shoots of healthy tejocote trees. Significant lesions were observed on all shoots inoculated with the three N. luteum isolates (designated UCR1190, UCR1191, and UCR1192), but not on the shoots inoculated with other isolates or the non-inoculated controls. Results indicated that all three N. luteum isolates are aggressive pathogens on tejocote. This pathosystem should be further studied with a goal of designing appropriate disease management strategies

Identification of Species of Botryosphaeriaceae Causing Bot Gummosis in Citrus in California

Members of the Botryosphaeriaceae family are known to cause Bot gummosis on many woody plants worldwide. To identify pathogens associated with Bot gummosis on citrus in California, scion and rootstock samples were collected in 2010 and 2011 from five citrusgrowing counties in California. Symptoms observed on citrus included branch cankers, dieback, and gumming. Various fungal species were recovered from necrotic tissues of branch canker and rootstock samples. Species were identified morphologically and by phylogenetic comparison as ‘Eureka’ lemon, ‘Valencia’, ‘Washington Navel’, ‘Fukumoto’, grapefruit, ‘Satsuma’, and ‘Meyer’ lemon. Species were identified morphologically and by phylogenetic comparison of the complete sequence of the internal transcribed spacer regions, β-tubulin gene, and elongation factor α-1 genes with those of other species in GenBank. A consensus-unrooted most parsimonious tree resulting from multigene phylogenetic analysis showed the existence of three major clades in the Botryosphaeriaceae family. In total, 74 isolates were identified belonging to the Botryosphaeriaceae family, with Neofusicoccum spp., Dothiorella spp., Diplodia spp., (teleomorph Botryosphaeria), Lasiodiplodia spp., and Neoscytalidium dimidiatum (teleomorphs unknown) accounting for 39, 25, 23, 10, and 3% of the total, respectively. On inoculated Eureka lemon shoots, lesion length was significantly different (P \u3c 0.05) among 14 isolates recovered from portions of cankered tissues of the original trees. Lesion lengths were significantly longer (P \u3c 0.05) for shoots inoculated with isolates of Neofusicoccum luteum and shorter for shoots inoculated with isolates of Dothiorella viticola (P \u3c 0.05) than those of other species. Identifying the distribution and occurrence of these fungal pathogens associated with Bot gummosis is useful for management applications during occasional outbreaks in California

Identifying Polyphagous and Kuroshio Shot-Hole Borer in California

The Invasive Shot-Hole Borer is a new, rapidly spreading, invasive pest threatening landscape trees and commercial avocado groves. The beetle is a vector for the plant disease fusarium dieback. First detected in the Los Angeles basin in 2012, it has quickly spread as far north as San Luis Obispo. Currently there are no control measures for the disease. While the current economic impact to crops is focused on avocados, computer models suggest almond to be a potential host. This publication explains the life cycle, biology and identification, look-alike pests, signs and symptoms of infestation and damage, reproductive hosts, and landscape and agricultural host species

Fungal trunk pathogens of Sultana Seedless vineyards in Aegean region of Turkey

In recent years, grapevine trunk diseases have become a problem in Sultana Seedless vineyards of Manisa and Izmir provinces (Aegean Region, Turkey). A field survey was conducted in 2013 in these provinces (in 8 cities and 80 vineyards) to determine disease incidence, fungal species associated with grapevine trunk diseases and pathogenicity.  Symptomatic vines were grouped by two different grapevine trunk disease symptoms: (1) typical tiger-striped leaves, (2) dead arm, shoot decline or apoplexy. Over 80% of vineyards in these areas were positive for at least one characteristic trunk disease symptom. Incidence of tiger-stripe symptom ranged from 2.9-15% and incidence of apoplexy ranged from 0–4.2%. Eight fungal species in five fungal families were identified from declining grapevines based on morphological and molecular (ITS, β-tubulin and EF1-α) studies including, Botryosphaeria dothidea, Diplodia seriata, Lasiodiplodia theobromae, Neofusicoccum parvum, Diaporthe ampelina, Phaeomoniella chlamydospora, Togninia minima and Fomitiporia mediterranea. Overall, D. ampelina was the most frequently recovered fungus from symptomatic grapevine tissues followed by botryosphaeriaceous fungi, P. chlamydospora, F. mediterranea and T. minima. Pathogenicity tests confirmed all eight fungi as pathogens of grapevine in these regions with N. parvum being the most virulent among the fungi tested

Buğdayda (Triticum aestivum L.) protoplast izolasyonu, kültürü ve bitki regenerasyonu

TEZ2463Tez (Doktora) -- Çukurova Üniversitesi, Adana, 1996.Kaynakça (s. 128-141) var.xii, 143 s. : rnk. res. ; 30 cm.…Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi Tarafından Desteklenmiştir

Biological and chemical pruning wound protectants reduce infection of grapevine trunk disease pathogens

Grapevine trunk diseases (GTDs) are currently considered some of the most important challenges for viticulture, curtailing vineyard longevity and productivity in nearly every raisin, table and wine grape production region in California and worldwide. Pruning wounds provide the main entry point for fungal pathogens responsible for these diseases; pathogens enter the wounds following precipitation events. The aim of this study was to evaluate the efficacy of selected chemical and experimental biological fungicides for protection of pruning wounds against two of the most common and virulent fungal pathogens causing GTDs: Eutypa lata and Neofusicoccum parvum. This study was conducted on sauvignon blanc at the UC Davis Department of Plant Pathology Field Station. Results showed that several chemical and biological fungicides, notably the chemical fungicide Luna Sensation, the biofungicide Vintec and a combination of the biofungicides Bio-Tam and CrabLife Powder, provided significant protection against at least one of the two canker pathogens used in this study. However, the majority of products tested did not provide simultaneous control of both E. lata and N. parvum pathogens, highlighting the continuing challenge of controlling GTDs