Maize In Iran Research Articles

Declaration of Fumonisin as the Main Dangerous Mycotoxin Produced by Fusarium Species on Maize in Iran

Our study showed Fusarium spp. can be the most important fungal pathogen of maize causing severe yield losses and producing fumonisins that concern human and animal damages. Actually, other mycotoxins such as aflatoxin contamination have become regular in maize but the appearance of fumonisins was more frequent. However, the fluctuation between years and regions can affect the severity of the infection and then fumonisin production level. This mycotoxin was defined as fumonisin B1, fumonisin B2 and fumonisin B3 with diverse actions. The level of production, concentrations, and damages of fumonisins were found in different locations of maize fields in Iran. However, the fumonisin contents of the isolated samples were more diverse than in other locations. Toxin composition and maximum values differ significantly throughout the climate conditions and maize cultivars. The resistance cultivar of maize against the Fusarium pathogen can be helpful in controlling fumonisin production on the field effectively.

Increased heat stress risk for maize in arid-based climates as affected by climate change: threats and solutions

Heat stress in combination with drought has become the biggest concern and threat for maize yield production, especially in arid and hot regions. Accordingly, different optimal solutions should be considered in order to maintain maize production and reduce the risk of heat stress under the changing climate. In the current study, the risk of heat stress across Iranian maize agro-ecosystems was analyzed in terms of both intensity and frequency. The study areas comprised 16 provinces and 24 locations classified into five climate categories: arid and hot, arid and temperate, semi-arid and hot, semi-arid and temperate, and semi-arid and cold. The impact of heat stress on maize under a future climate was based on a 5-multi-model ensemble under two optimistic and pessimistic emission scenarios (RCP4.5 and RCP8.5, respectively) for 2040-2070 using the APSIM crop model. Simulation results illustrated that in the period of 2040-2070, intensity and the frequency of heat stress events increased by 2.37°C and 79.7%, respectively, during maize flowering time compared to the baseline. The risk of heat stress would be almost 100% in hot regions in the future climate under current management practices, mostly because of the increasing high-risk window for heat stress which will result in a yield reduction of 0.83 t ha-1. However, under optimal management practices,farmers will economically obtain acceptable yields (6.6 t ha-1). The results also indicated that the high-risk windows in the future will be lengthening from 12 to 33days in different climate types. Rising temperatures in cold regions as a result of global warming would provide better climate situations for maize growth, so that under optimistic emission scenarios and optimal management practices, farmers will be able to boost grain yield up to 9.2 t ha-1. Overall, it is concluded that farmers in hot and temperate regions need to be persuaded to choose optimal sowing dates and new maize cultivars which are well adapted to each climate to reduce heat stress risk and to shift maize production to cold regions.

A comparative study in quantification of maize evapotranspiration for Iranian maize farm using SEBAL and METRIC-1 EEFLux algorithms

A comparative study in quantification of maize evapotranspiration for Iranian maize farm using SEBAL and METRIC-1 EEFLux algorithms

Genetic structure of Fusarium verticillioides populations from maize in Iran

Fusarium verticillioides is one of the most important fungal pathogens of maize since it causes severe yield losses and produces the mycotoxins fumonisins that represent a major concern for human and animal health. Information about genetic diversity and population structure of fungal pathogens is essential for developing disease management strategies. The aim of this research was to investigate the genetic structure of F. verticillioides isolated from different provinces of Iran through determination of mating type idiomorphs, phylogenetic analyses based on translation elongation factor-1 alpha (EF-1α), RNA Polymerase II Subunit (RPB2), beta-tubulin (tub2) and Calmodulin (cmdA) genes and genetic diversity analyses based on 6 simple-sequence repeats (SSRs). Both mating types were detected in Iranian populations of F. verticillioides, particularly in Qazvin and Khuzestan, with equal frequency, which highlighted that sexual reproduction is favorable under field conditions. However, the linkage disequilibrium indices did not support the hypothesis of random mating in Khuzestan and Fars. Although assessment of nucleotide diversity based on housekeeping genes showed low level of variation among strains, genotype diversity based on SSRs revealed a high level of genetic diversity within Iranian populations. AMOVA analysis highlighted that the genetic variation of F. verticillioides in Iran was mainly distributed within population of a single area (97%), while a small proportion of genetic variation (3%) resided among populations. These patterns of variation are likely explained by the continuous gene flow among populations isolated from different areas. On the other hand, principal coordinate analysis indicated that the distribution of genetic variation among populations could be explained by the geographical distances. Consequently, to reduce pathogen gene flow among regions, the quarantine processes in Iran should be intensified.

Tracing the Origin and Evolutionary History of Pyricularia oryzae Infecting Maize and Barnyard Grass.

Blast disease is a notorious fungal disease leading to dramatic yield losses on major food crops such as rice and wheat. The causal agent, Pyricularia oryzae, encompasses different lineages, each having a different host range. Host shifts are suspected to have occurred in this species from Setaria spp. to rice and from Lolium spp. to wheat. The emergence of blast disease on maize in Iran was observed for the first time in the north of the country in 2012. We later identified blast disease in two additional regions of Iran: Gilan in 2013 and Golestan in 2016. Epidemics on the weed barnyard grass (Echinochloa spp.) were also observed in the same maize fields. Here, we showed that P. oryzae is the causal agent of this disease on both hosts. Pathogenicity assays in the greenhouse revealed that strains from maize can infect barnyard grass and conversely. However, genotyping with simple sequence repeat markers and comparative genomics showed that strains causing field epidemics on maize and on barnyard grass are different, although they belong to the same previously undescribed clade of P. oryzae. Phylogenetic analyses including these strains and a maize strain collected in Gabon in 1985 revealed two independent host-range expansion events from barnyard grass to maize. Comparative genomics between maize and barnyard grass strains revealed the presence or absence of five candidate genes associated with host specificity on maize, with the deletion of a small genomic region possibly responsible for adaptation to maize. This recent emergence of P. oryzae on maize provides a case study to understand host range expansion. Epidemics on maize raise concerns about potential yield losses on this crop in Iran and potential geographic expansion of the disease.

Mycotoxins produced by fusarium species associated with maize ear rot in Iran

Mycotoxins contamination is one of the most important problems worldwide in maize that can cause serious threat for human and animal health. The aim of this study was to determine the ability of Fusarium species associated with maize ear rot to produce diverse mycotoxins. The results showed, One out of three isolates of F. subglutinans produced detectable level of Beauvericin (BEA); the only isolate of F. temperatum produced 302 µg/g of BEA. Two out of five isolates of F. redolens produced enniatin B1and four isolates of this species produced high levels of BEA. As well, 21 isolates of Fusarium incarnatum-equiseti species complex (FIESC) and one isolates of F. brachygibbosum were evaluated for production of trichothecens (T-2 toxin, HT-2 toxin, Diacetoxyscirpenol (DAS), nivalenol (NIV) and deoxynivalenol (DON)), zearalenone (ZEN), enniatins (ENN A, A1, B and B1) and BEA by HPLC. Production of trichothecens, ZEN and BEA with one, three and four isolates of FIESC, respectively were observed and one isolate of F. brachygibbosum only produced detectable level of DAS and ENN B1. Analyzing of moniliformin production of F. proliferatum (26 isolates), FIESC (21 isolates) and F.thapsinum (10 isolates) showed none of them produce this toxin. These results revealed the ability of Fusarium spp. from maize to produce a varied range of mycotoxins which are harmful to human and animal’s health. Therefore, the occurrence of such broad number of different species on Iranian maize could be reason of great concern because of the toxigenic risk associated to these species.

Isolation, Molecular Identification and Mycotoxin Profile of Fusarium Species Isolated from Maize Kernels in Iran.

Fusarium species are among the most important fungal pathogens of maize, where they cause severe reduction of yield and accumulation of a wide range of harmful mycotoxins in the kernels. In order to identify the Fusarium species and their mycotoxin profiles associated to maize ear rot and kernel contamination in Iran, a wide sampling was carried out from field in ten major maize-producing provinces in Iran, during 2015 and 2016. From 182 samples of maize kernels, 551 strains were isolated and identified as belonging to Fusarium genus. Among the 234 representative strains identified at species level by translation elongation factor (EF-1α) sequences, the main Fusarium species were F. verticillioides and F. proliferatum, together representing 90% of the Iranian Fusarium population, and, to a lesser extent, F. incarnatum equiseti species complex (FIESC), F. thapsinum and F. redolens. Fumonisin (FBs) production by F. verticillioides and F. proliferatum representative strains was analysed, showing that all strains produced FB1. None of F. verticillioides strains produced FB2 nor FB3, while both FB2 and FB3 were produced only by F. proliferatum. Total mean of FBs production by F. verticillioides was higher than F. proliferatum. The occurrence of different Fusarium species on Iranian maize is reason of great concern because of the toxigenic risk associated to these species. Moreover, the diversity of the species identified increases the toxigenic risk associated to Fusarium contaminated maize kernels, because of the high possibility that a multi-toxin contamination can occur with harmful consequences on human and animal health.

The consequences of change in management practices on maize yield under climate warming in Iran

The potential impacts of climate warming on grain yield, water, and nitrogen consumptions of maize have been repeatedly assessed across different regions of the world. However, to date, there is no comprehensive, large-scale evaluation on the effects of climate warming on the cropping systems of Iran. The objective of the current study was to quantify the effects of climate warming on the length of the growing period and grain yield of maize. We also tested the potential of changes in irrigation, nitrogen application rate, and using late maturity cultivars of maize to offset the negative impact of climate warming in order to maintain the current levels of grain yield (4 to 10 t ha−1 depending upon the province) in Iran. The crop modeling framework SIMPLACE was used to evaluate the effects of the warming temperatures, nitrogen application rate, and changes in thermal requirements of the cultivar scenario combinations on grain yield of maize in Iran. The climate, soil, and management inputs of the crop model were obtained from global datasets as grid cells at 0.5° × 0.5° resolution, and the outputs of the crop model were aggregated to the province level. Results of the grain yield projections showed a decline (− 0.1 to − 22%) in maize, especially in the Southern provinces (Khuzestan, Fars, and Kerman) under different warming scenarios by + 0.5 to + 2 °C, an increase from the baseline. The grain yield decline appeared to be mainly driven by a shortening of the length of the growing season and extreme heat stress during anthesis, the most sensitive period of crop growth. Increasing temperatures during the growing season lead to a marginal increase of absolute irrigation requirements over the maize growing areas. For all provinces, application of 10–25% more nitrogen than the current rate (170 kg N/ha-1) was able to offset the negative effects of higher temperatures (+ 0.5 and + 1.0 °C) during the growing season. However, the increased nitrogen application rates were not able to maintain the baseline level of grain yield under the + 1.5 and + 2.0 °C warming scenarios. Introducing late maturity cultivars, which required 20% more temperature sum than current cultivars to reach maturity, improved the grain yield in the cooler provinces by up to 10%. In conclusion, the grain yield baseline level may not be maintained under the highest magnitude of warming by increasing nitrogen application rates or using late maturity cultivars. Furthermore, more water is needed to produce a unit of grain under a warming climate. This study also suggests that combined adaptation strategies should be considered by policymakers in order to mitigate the negative impact of climate warming on the cropping systems of Iran.

Evaluation of Maize Inbred Lines for Iranian maize mosaic virus (IMMV) Resistance

Evaluation of Maize Inbred Lines for Iranian maize mosaic virus (IMMV) Resistance

Studies on Aspergillus Flavus Link. Isolated From Maize in Iran

Abstract The Aspergillus flavus population structure from maize kernels was examined. During 2011, samples were collected from two main grain maize production areas in Iran (Fars and Ardebil provinces), shortly before harvest. One-hundred nine A. flavus isolates were recovered on Dichloran Rose Bengal Chloramphenicole (DRBC) agar and Aspergillus flavus/parasiticus medium (AFPA) and grouped into morphotypes and Vegetative Compatibility Groups (VCGs) based on morphological (e.g. sclerotia production), physiological (e.g. aflatoxin-producing ability) and genetic criteria (e.g. heterokaryosis). In general, morphotype and VCG composition were highly dissimilar in both provinces. In total, 43.8% and 44.3% of A. flavus isolates from Ardebil and Fars, respectively, produced sclerotia. Sclerotia producers were identified as A. flavus L and S strain morphotypes in Ardebil (66.7% and 33.3%, respectively) and Fars (29.6% and 70.4%, respectively). Furthermore, 71 isolates (65.1%) were able to produce aflatoxin (Ardebil 40.8%, Fars 59.2%). The aflatoxin values were categorized into four different classes (< 10, 10-100, 100-1,000 and > 1,000 ppb). In total, 51 aflatoxin producing isolates of A. flavus (Ardebil n = 22, Fars n = 29) were assigned into 26 VCGs by complementation of nit auxotrophs on nitrate medium. None of the A. flavus isolates from Ardebil complemented with any isolates from Fars. Genetic diversity of A. flavus isolates was 59.1% and 41.8% for Ardebil and Fars, respectively. The different geographical adaptation and genetic make-up of A. flavus isolates may be due to different climatic conditions, soil types and crop sequences in both maize production areas.

Stability of General and Specific Combining Ability Effects for Grain Yield in Elite Iranian Maize Inbred Lines

Diallel analyses provide estimates of general combining ability (GCA) and specific combining ability (SCA) effects to facilitate efficient utilization of maize (Zea mays L.) inbred lines in breeding programs. Multi-environment trials are commonly conducted to evaluate GCA, SCA, and the stability of grain yield (GY) for single-crosses across environments (E). In these studies the significant GCA × E and SCA × E interactions are usually not examined, yet they indicate that the rankings of the parental inbred lines for GCA and SCA change across environments. The major objective of this study was to quantify stability of GCA and SCA effects of nine maize inbred lines developed in Iran using a 9 × 9 diallel mating design. The 36 single- cross hybrids were evaluated for GY, kernel rows per ear (KR), and kernels per row (KN) at three locations across two years (six environments), using a randomized complete-block design with four replicates. Rank sum and rank variance were used to measure the stability of GCA and SCA for GY across environments, and the Quade's test was used to separate the rank sums. The main effect of E, hybrid, and hybrid × E was significant. Significant GCA and SCA effects were found for the traits, with GCA being more important than SCA for KR, but vice versa for GY and KN. Significant GCA × E and SCA × E were observed for the traits, indicating changes in ranking of GCA and SCA across environments. Inbred lines KE75039 and K1263/2-1 had significant positive GCA for GY. The highest SCA for GY resulted from KE75039 × K2331 cross (15.07 Mg ha−1). Ranking of GCA and SCA for GY across environments exhibited different patterns for the parental inbred lines. Inbreds KE75039 and K1263/2-1 exhibited high stability for GCA across environments for GY, and they contributed only 9% and 7% to GCA × E interaction, respectively. Cross combination KE75039 × K2331 had the highest stability for SCA across the environments, followed by K2331 × K1263/2-1 and K1263/1 × OH43/1-43 crosses. The three other notable cross combinations with relatively stable SCA each had inbred line K1263/1 in common. Combining ability and stability analyses suggest that maize breeding programs in Iran could improve GY by using inbred lines KE75039, K1263/1, and K1263/2-1. It is suggested that new adapted germplasm be introduced to broaden the genetic base of maize germplasm available in Iran.

Determination of combining abilities and heterotic patterns of fourteen medium to late maturing Iranian maize inbred lines using diallel mating design

Information about how elite maize (Zea mays L.) inbreds of different pedigree sources combine and perform in hybrid combinations will facilitate the selection of parents and breeding strategies for hybrid development. Fourteen medium to late maturing maize inbred lines, derived from the most commonly used source materials in maize breeding programs in Iran, were crossed in a diallel mating design. The 91 F1 hybrids and the 14 parental lines were evaluated during two years at four locations in Iran for investigation of combining abilities and to determine heterotic patterns among germplasm sources, using a biplot diallel analysis. The graphical representation offered by biplot analysis allowed a rapid and effective overview of general combining ability (GCA) and specific combining ability (SCA) effects of the inbred lines, their performance in crosses, as well as grouping patterns of similar genotypes. GCA and SCA effects were significant for grain yield (GY), number of kernel row per ear (RE), kernel number per row (KR) and thousand-kernel weight (TKW). Based on significant positive GCA effects, the lines derived from LSC could be used as parent in crosses to increase GY, KR, and TKW. The maximum best-parent heterosis values and high SCA effects resulted from crosses B73 × MO17 and A679 × MO17 for GY; K3640/5× K19/1 for TKW; K3653/2 × MO17, B73 × MO17 and A679 × MO17 for KR; and B73 × K3640/5 for RE. The best heterotic patterns were LSC × RYD, LSC × SYN L. and RYD × SYN L., which would be potentially useful in maize breeding programs to obtain high-yielding hybrids in the same climate of Iran. Key words: Maize (Zea mays L.), heterotic pattern, biplot diallel analysis, general combining ability, specific combining ability, heterosis.

Natural Occurrence of Aflatoxins from Maize in Iran

Fifty-one maize samples, intended for animal feed and human consumption, were collected from the four main maize production provinces in Iran and analyzed by high-performance liquid chromatography (HPLC) for contamination by four naturally occurring aflatoxin analogues (AFB1, AFB2, AFG1, and AFG2). AFB1 was detected in 58.3, and 80% of the maize samples obtained from Kermanshah and Mazandaran provinces, respectively. The maximum AFB1 (276.3 μg/kg) and highest level of total aflatoxins (AFT) (316.9 μg/kg) were detected in a maize sample collected from Kermanshah province. The mean aflatoxin level from contaminated samples (52.60 μg/kg) from Kermanshah was significantly higher (P < 0.0001) than those in maize from the other three provinces and exceeded all the maximum tolerated levels (MTLs) set for AFT in maize. The level of AFB1 in 15.68% of the total samples was above the MTL (5 μg/kg) for AFB1 in maize in Iran. The mean contamination level of AFT (23.86 μg/kg) in the positive samples was higher than MTL for maize in Iran (20 μg/kg) intended for animal feed. The levels of AFB1, AFB2, AFG1, and AFG2 ranged between not detected (<0.1 μg/kg) and 276.3, 30.4, 9.1, and 1.1 μg/kg in maize grain, respectively.

The effects of market factors and government policies on maize marketing in Iran

Maize plays a unique role in the agricultural economic of world. It is a key stable crop which is used in a wide range of food industries and as a customary livestock feed in Iran. Also, it is one of the most widely traded commodities in terms of absolute import value and the ratio of its amount to the total production value. Most of the traded maize in Iran is used for feed and smaller amounts are for industrial and food uses. Agriculture policy reforms in Iran have generated higher disposable incomes and increase livestock production that worked to expand maize domestic consumption faster than domestic production. In order to investigate the effect of government agriculture policies on maize market and trade restriction in Iran during 1989 to 2006 period, in this paper the advanced simultaneously econometric model is used in order to study the acreage planted, domestic demand and production, import demand and marketing margin functions. The results showed that government policies were ineffective. Therefore price support policy was not efficient for the maize market regulation. Furthermore, since government intervention in the market did not result stabilization and regulation of the maize market in practice, so the support from private sector and less restriction on trade are suggested.

Interference between maize and Xanthium strumarium or Datura stramonium

Karimmojeni H, Rahimian Mashhadi H, Alizadeh HM, Cousens RD &amp; Beheshtian Mesgaran M (2010). Interference between maize and Xanthium strumarium or Datura stramonium. Weed Research50, 253–261.Summary Xanthium strumarium and Datura stramonium are two of the most important weeds of maize in Iran. Their growth was compared in a field study conducted over 2 years. Relationships were derived between weed density and crop yield, yield components and various growth parameters. Yield, grain number ear−1 and grain weight were affected more by X. strumarium than by D. stramonium. Xanthium strumarium followed a pattern of growth resembling that of the maize, whereas D. stramonium continued growing for a longer period, mainly affecting maize during the grain‐filling period. A large portion of the loss in maize yield caused by X. strumarium could be explained by a reduction in grain number ear−1, whereas a greater portion of the maize yield loss from D. stramonium was explained by a reduction in grain weight. Weed biomass was greater for X. strumarium than for D. stramonium, whereas seed production was higher for D. stramonium. It is concluded that although X. strumarium should be given the highest priority for control in maize on the basis of its superior competitive ability, control of D. stramonium is also essential because of both its considerable competitiveness in the current crop and its long‐term effects resulting from its greater seed production.

Dissection of Drought Stress as a Grain Production Constraint of Maize in Iran

Dissection of Drought Stress as a Grain Production Constraint of Maize in Iran

Biplot analysis for multi-environment trials of maize (Zea mays L.) hybrids in Iran

Adapted maize (Zea mays L.) hybrids should be identified and chosen based on multi-environment trials analysing several traits. The objectives of this study were to identify mega-environments and suitable adapted maize hybrids based on both mean grain yield and grain yield stability and were to evaluate the 14 maize hybrids based on several desirable traits. Biplot analysis determined one mega-environment and two sectors that consist of one location in each sector for maize in Iran. The mega-environment included Kerman (KRM), Kermanshah (KSH), Moghan (MGN), Dezfol A (DZF A), Karaj (KRJ), Darab (DRB), Dezfol B (DZF B), Shiraz B (SHZ B), and Esfahan (ESF), where hybrid OSSK 602 was the best performing hybrid. The first sector included Khoramabad (KHM) where BC 678 was the best hybrid, and the second sector included Shiraz A (SHZ A) where ZP 599 was the hybrid with the highest performance. OSSK 602 was the best hybrid among all of the studied hybrids followed by ZP 677 and ZP 684. The genotype × trait biplot indicated that ZP 677 and OSSK 602 had greater thousand-kernel weight and grain number, whereas ZP 684 had longer day to maturity and larger cob diameter. KSC 700, KSC 704, and BC 678 had higher ear height and more days to tasseling than other hybrids. The genotype × trait biplot graphically displayed the interrelationships among traits and it was used in identifying hybrids that are good for some particular traits.

Occurrence of fumonisins in maize imported into Iran during 2001–2002

Fumonisins, fungal toxins found primarily in maize and produced by various Fusarium species, have been shown to cause a variety of significant adverse health effects in livestock and experimental animals, and are probable human carcinogens. Thirty-three maize samples were collected at ports from bulk shipments, which were imported into Iran from six countries during 2001-2002, and analysed by HPLC for the most abundant of the naturally occurring fumonisin analogues, namely fumonisins B1 (FB1), B2 (FB2) and B3 (FB3). Of the 33 samples, 21 (64%) were found to contain FB1 (58-512μg/kg) at levels above 10μg/kg. The frequency of FB1 found in maize samples imported from Uruguay and Canada was 75%, followed by China and Argentina (67%), USA (60%), and Brazil (50%). The average FB1 level was 266 and 169μg/kg for positive and all samples, respectively. Medians were 250 and 146μg/kg for positive and all samples, respectively. FB2 levels ranged from not detected (<10μg/kg) to 53μg/kg, whereas no sample had an FB3 level above the detection level (10μg/kg). This is the first report of fumonisin contamination of imported maize in Iran. Although, the level of all detected fumonisins were below the Iranian and FDA tolerance levels for foods and feeds, It is necessary to maintain the strict rules to ensure continued safety of imported maize.

Analysis of nucleotide sequence of Iranian maize mosaic virus confirms its identity as a distinct nucleorhabdovirus

The nucleotide sequence of the Iranian maize mosaic rhabdovirus (IMMV) was obtained using a random-PCR method (rPCR) followed by PCR with specific primers. Analysis of the complete nucleotide sequence of the IMMV genes and intergenic regions comprising a total of 12,381 nucleotides (including the partial sequences of leader and trailer regions) revealed six open reading frames (ORF) on the viral complementary RNA (vcRNA). On the basis of its similarities to other rhabdovirus sequences, the IMMV genome consists of 3'-leader-N-P-3-M-G-L-5'-trailer. The intergenic regions contained a characteristic consensus sequence, 3'-AAUUCUUUUUGGGUUU/G-5'. The IMMV gene products showed a high similarity to those of maize mosaic virus and taro vein chlorosis virus and a more distant relationship to other rhabdoviruses. Together with the biological, serological and morphological features described earlier, our molecular data provide evidence that IMMV is a distinct member of the genus Nucleorhabdovirus in the family Rhabdoviridae.

Genetic diversity of Fusarium verticillioides isolates from maize in Iran based on vegetative compatibility grouping.

SUMMARY Genetic diversity among Fusarium verticillioides isolates was analyzed using vegetative compatibility groups (VCGs). Forty-four isolates of F. verticilliodes from stalks and seeds were recovered in maize-producing areas in Iran during 2004-2005. Chlorate-resistant nitrate non-utilizing (nit) mutants were recovered from selected isolates of F. verticillioides and used in complementation (heterokaryon) tests. Vegetative compatibility tests by pairing nit mutants identified 25 VCGs among 44 isolates. Twenty-one isolates belonged to single-member VCGs and the remaining 23 isolates belonged to four multimember VCGs. VCG1 was the largest group and included 17 isolates, whereas the other three multimember VCGs contained two isolates each. It is concluded that natural populations of F. verticillioides in Iran are genetically highly divergent and include isolates representing a potential risk for disease development. rot. Fusarium verticillioides (Sacc.) Nirenberg [Gibberella fujikuroi (Sawada) Wollenw., mating population A], a prevalent pathogen of agriculturally important crops