Occurrence of Powdery Mildew Caused by Leveillula taurica on Onion (Allium cepa) in Iran.

During September of 2009, leaves of a local cultivar (yellow bulb) of onion (Allium cepa L.) in the late vegetative growth stage were heavily infected with powdery mildew in the Birjand Region (Giuq Sofla), southern Khorasan, Iran. Disease symptoms included circular to oblong, chlorotic to necrotic lesions that were 1 to 2 cm in diameter as well as white and effuse colonies on young and mature leaves. On the basis of microscopic examination, the whitish powdery colonies consisted of conidiophores and conidia. Conidiophores emerged from stomata, singly or branched in groups of two to three, and formed dimorphic conidia. The primary conidia were lanceolate with a narrowed apex (17.5 to 20 × 55.4 to 67.5 µm) and the secondary conidia were cylindrical to ellipsoid (17.5 to 22.5 × 55 to 70 µm). The teleomorph of the fungus was not observed. Leveillula taurica (Lév.) G. Arnaud (anamorph Oidiopsis sicula Scalia) was subsequently identified by the presence of endophytic mycelia emerging through stomata, branched conidiophores, and hyaline, single-celled, dimorphic conidia borne singly (1,3). To confirm pathogenicity, conidia from diseased onion leaves were brushed onto leaves of 35- to 40-day-old onion plants in triplicate. The inoculated plants were subsequently covered with plastic bags for 3 days to maintain high humidity. After 12 to 14 days, symptoms of powdery mildew appeared on the leaves of inoculated plants. No symptoms developed on the noninoculated plants. Powdery mildew caused by L. taurica on onion has previously been reported from the United States, Brazil, Israel, and Sudan (4). Although this pathogen has previously been reported on Allium spp. by Khodaparast et al. (2) in Iran, to our knowledge, this is the first record of powdery mildew of onion (A. cepa L.) from Iran. The disease outbreak has recently been noted on onion in Aryan Shahr, 70 km north of Giuq Sofla where the pathogen was originally identified. Voucher specimens have been deposited at the Fungal Collection of the Ministry of Agriculture, Tehran, Iran. References: (1) L. J. du Toit et al. Online publication. doi:10.1094.PHP/1129-01-HN. Plant Health Progress. 2004. (2) S. A. Khodaparast et al. Rostaniha 4:108, 2003. (3) S. K. Mohan and N. D. Molenaar. Plant Dis. 89:431, 2005. (4) A. Reis et al. Hortic. Bras. 22:758, 2004.

Association of Microascus cirrosus (Microascaceae, Ascomycetes) with Brown Leaf Spot of Pistachio in Iran.

Iran is the largest pistachio-producing and exporting country in the world with an annual production of approximately 200,000 t. In July 2009, brown spots were noticed on the leaves of an unknown cultivar of pistachio (Pistacia vera L.) in the Mazhan Region of Birjand, South Khorasan, Iran. Nearly 20% of the trees in the surveyed area (1 ha) showed irregularly shaped leaf spots that were mainly on the abaxial surface, measured 4 to 6 mm in diameter, and were initially pale brown but progressively became dark brown. Lesions were cut from diseased tissues, surface sterilized, and placed on acidified potato dextrose agar (APDA). An anamorphic fungus was consistently isolated from the tissues. The fungus was identified as Microascus cirrosus Curzi (1,4). Colonies on PDA at 25°C reached 9 mm in diameter in 7 days and appeared olivaceous brown and zonate, and perithecia developed in 14 days. Perithecia were black, superficial or partially immersed, spherical, 110 to 200 µm in diameter, with cylindrical necks measuring up to 60 µm long by 25 to 35 µm broad; asci were globose to ovate, eight spored, and 9 to 11 × 8 to 10.5 µm; ascospores were pale reddish brown, variable in shape, ranging from concavo-convex, sometimes plano-convex to oval, and 4.5 to 6 × 3 to 4 µm. The associated anamorph on PDA was a Scopulariopsis sp. with annellophores borne singly or in groups of two or three, 10 to 16 × 2.5 to 3.5 µm, with abruptly narrowed apices; conidia were produced in chains, globose to subglobose, basally truncate, pale olive to fuscous, and 4 to 5 × 3 to 4 µm; chlamydospores were globose to pyriform, terminal or intercalary, and 8.5 to 17.5 µm in long axis. Pathogenicity of two isolates was tested using the filter-paper method of Takahashi et al. (3). Mycelial plugs (5 mm in diameter) as well as filter papers containing conidia were placed on five needle-wounded or nonwounded attached leaves of pistachio cv. Kale-Ghuchi in triplicate. The leaves were covered with a translucent plastic bag for 4 days. Inoculated detached and inoculated wounded attached leaves showed symptoms after 6 and 9 days on 5-month-old and 2-month-old leaves, respectively. Control leaves (five in triplicate) remained symptomless. The pathogen was frequently reisolated from the margins of the lesions. To our knowledge, this is the first record of M. cirrosus occurring on pistachio as well as the first report of a member of this genus from Iran. The same fungus has been reported as the causal agent of stored corn deterioration in the United States (1). M. cirrosus also produced a dimorphic yeast phase on PDA but not on malt extract agar or water agar. Cultures with partial reversion developed chlamydospore-like cells. Higher temperatures (25 to 30°C) and surface-sterilized pistachio leaves placed on PDA accelerated the reversion of the yeast phase to hyphal phase. Although dimorphism has been reported in other plant pathogenic fungi (2), this is the first report of dimorphism in this fungus and of a dimorphic fungus attacking pistachio. Further investigations are needed to determine the relation between dimorphism and pathogenicity. A culture (IRAN 1497 C) of the fungus is preserved by R. Zare. References: (1) G. L. Barron et al. Can. J. Bot. 39:1609, 1961. (2) M. Nadal et al. FEMS Microbiol. Lett. 284:127, 2008. (3) W. Takahashi et al. J. Plant Pathol. 91:171, 2009. (4) J. A. von Arx. Persoonia 8:191, 1975.

A new report of pre-harvest ear rot of corn caused by Geotrichum candidum from Iran.

In summer of 2004, samples of husk looseness ear of corn (Zea mays) (cv. 700-Karaj) were collected from corn fields in Ali-Abad (Jiroft region), Kerman province, Southeastern Iran, for diagnosis of an unusual ear decay. A fungus was isolated from the rotting kernels and subsequently identified as Geotrichum candidum. The fungal pathogen was found to be closely related to G. citri-aurantii (citrus race) based on morphological, physiological and pathogenicity properties. The fungal pathogenicity test was demonstrated by fulfilling Koch's postulates. The pathogen caused rot disease on husk looseness corn kernels in soft-dough stage of ripening. The fungus was also pathogenic on ripe lemon and green and ripe tomato fruits. Fungal isolates of corn were compared to isolates from soft-rotten potato tubers. These two groups of isolates were highly similar on the basis of their morphological, biochemical and pathogenicity characteristics. To our knowledge, this is the first known report of corn ear rot caused by G. candidum in the world.

Study of the effects of raw garlic consumption on the level of lipids and other blood biochemical factors in hyperlipidemic individuals.

Hyperlipidemia is one of the famous disorders that can lead to atherosclerosis. Garlic has been considered as one of the blood lipids lowering agents for ages, and various studies have been carried out, some of them confirmed this effect of garlic and some did not. The aim of this study was to evaluate the effect of raw garlic consumption on human blood biochemical factors in hyperlipidemic individuals. This clinical trial was conducted on 30 volunteer individuals with blood cholesterol higher than 245 mg/dl. Fasting blood samples were collected for biochemical tests. The volunteers consumed 5 g raw garlic twice a day for 42 days. Second fasting blood samples were collected and the individuals did not use any kind of garlic for next 42 days. After that, the third fasting blood samples were collected and the biochemical factors were measured. After 42 days of garlic consumption the mean of blood total cholesterol (p<0.001) triglycerides (p<0.01) and FBS (p<0.01) were reduced significantly, but HDL-C was increased (p<0.001) significantly. Following 42 days of no garlic consumption total cholesterol (p<0.001), triglycerides and FBS (p<0.05) were significantly increased and HDL-C (p<0.01) decreased. Garlic consumption alone can decrease serum lipids, but it cannot be used as the main therapeutic agent for hyperlipidemia. Garlic can be used in mild hyperlipidemia or when the patients cannot tolerate the chemical drugs.