نوع مقاله : مقاله پژوهشی

نویسندگان

• علی ملیحی پور ¹
• محمدعلی دهقان ²
• کمال شهبازی ³

¹ بخش تحقیقات غلات، مؤسسه تحقیقات اصلاح و تهیه نهال و بذر، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران

² مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان گلستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، گرگان، ایران

³ مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اردبیل، سازمان تحقیقات، آموزش و ترویج کشاورزی، پارس آباد، ایران

چکیده

کلیدواژه‌ها

• آلودگی دانه
• شاخص بیماری
• شدت بیماری
• وقوع بیماری
• Fusarium graminearum

عنوان مقاله [English]

Investigating the resistance to Fusarium head blight (FHB) among elite wheat genotypes from the South warm and dry zone of Iran

نویسندگان [English]

• Ali Malihipour ¹
• Mohammadali Dehghan ²
• Kamal Shahbazi ³

کلیدواژه‌ها [English]

• Disease incidence
• disease index
• disease severity
• Fusarium-damaged kernels (FDK)
• Fusarium graminearum

Extended Abstract

Introduction

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is one of the most destructive diseases of wheat which is common in warm and humid climates with high rainfall during flowering. This disease is one of the most important diseases of wheat especially in the North warm and humid zone and similar areas in Iran. The disease may also become important in the South warm and dry zone in years when weather conditions are conducive for the disease development. In this study, 28 elite wheat genotypes from the South warm and dry breeding program were investigated in order to identification and selection of resistant genotypes to FHB.

Materials and Methods

This study was carried out in a randomized complete block design (RCBD) with three replications under field conditions in two locations including Araghi-Mahalleh Agricultural Research Station, Gorgan, Golestan province, Iran and Moghan Agricultural Research Station, Parsabad, Ardabil province, Iran and in the greenhouse. To conduct the field experiments, at routine sowing date (late autumn), each of the experimental genotypes was sown on a 1.5-meter-long rows and routine operations were performed to bring the plants to adult stage. As soon as each genotype reached 50% flowering, its spikes were inoculated by spraying with a suspension of fungal spores (5×10⁴ spores per ml) using a backpack sprayer. This operation was repeated two days later. Mist irrigation was applied to the experimental nurseries to aid disease development. Three weeks after the first spore spraying, disease incidence and severity were recorded. Disease incidence was determined by calculating the percentage of infected spikes and disease severity on a 0-100% scale for each planting line. The disease index for each line was calculated by dividing the product of incidence and disease severity by 100. In addition, after harvesting the plants of each planting line, threshing them, and sampling the seeds obtained, infected and healthy seeds were counted, and the percentage of Fusarium-damaged kernels (FDK) for each line was determined. To investigate the reaction of the genotypes in the greenhouse, the experimental pots with a diameter and height of 15 cm, filled with a mixture of regular soil and peat moss (70% and 30%, respectively), and 8-10 seeds from each genotype were planted in each pot. The pots containing the seeds were placed in a greenhouse at a temperature of 25-30°C for 7-10 days to germinate. Then, the seedlings were thinned to six seedlings per pot and were placed outdoor under cold conditions in order to grow the seedlings at a relatively cool temperature to get better tillers and to produce more and stronger spikes. Two months after the seedlings grew outdoor, they were transferred to the greenhouse at a temperature of 25-30°C to grow into spikes. As soon as each spike from each genotype reached 50% flowering, it was point-inoculated with 10 microliters of the fungal spore suspension 5×10⁴ spores per ml) using a hand sampler. Three weeks after inoculation of each spike, the percentage of disease progress (disease severity) was measured by determining the ratio of infected spikelets to the total spikelets within the spike. 

Results and Discussion

Combined analysis of variance of data for several datasets including disease incidence, severity, and index and Fusarium-damaged kernels (FDK) from three environments showed significant differences among the genotypes. Simple analysis of variance of data of disease progress within the inoculated spikes (disease severity) in the greenhouse also showed significant differences among the genotypes. The present study showed that seven lines including S-93-25, S-93-23, S-93-12, S-93-24, S-93-27, S-93-10, and S-93-13, having an average rank of 3.8 to 8.3 from different variables of the disease from the field and greenhouse, had higher resistance to the disease. Three other lines including S-93-17, S-93-11, and S-93-15 were stand in the next places. It seems that presence of type I resistance in these lines has reduced their disease level. According to these results and the other results collected from the South warm and dry breeding program, the line S-93-15 was denominated as the new wheat cultivar “Sahar” for cultivation in this zone. The other lines mentioned above may also be relevant candidates for replacement with older cultivars.

Conclusions

Even though wheat FHB is not endemic in the South warm and dry zone in Iran, it can be epidemic if susceptible wheat cultivars are cultivated and weather conditions are conducive for the disease development. There are records of FHB epidemics and losses caused by the disease in this zone. Results of the present study showed variations in reaction to the disease among elite wheat genotypes tested under field and greenhouse conditions. Based on data of the present study and the other data collected from the South warm and dry breeding program, at least one wheat cultivar denominated as “Sahar” for cultivation in this zone and still there are chance of releasing other cultivars.

Author contributions

Conceptualization and methodology, A.M.; implement of greenhouse experiments and data collection, A.M.; cultivation and support of Gorgan field experiments, M.D.; Gorgan data collection, A.M. and M.D.; cultivation and support of Parsabad field experiments, K.Sh.; Parsabad data collection, A.M. and K.Sh.; formal data analysis, A.M.; writing—original draft preparation, A.M.; writing—review and editing, A.M.; visualization, A.M.; supervision, A.M.; project administration, A.M.; funding acquisition, A.M., M.D., and K.Sh. All authors have read and agreed to the published version of the manuscript.

Data availability statement

Data available on request from the authors.

Acknowledgements

We thank Esmaeil Ebrahimi-Meymand, Cereal Research Department, Seed & Plant Improvement Institute (SPII), AREEO, Karaj, Iran, Hossein Bohloul, Golestan Agricultural and Natural Resources Research and Education Center, AREEO, Gorgan, Iran, and Aziz Naseri, Ardabil Agricultural and Natural Resources Research and Education Center, AREEO, Parsabad, Iran for their technical assistance. All costs of this research were covered by the project No. 0-03-03-93342 approved by Seed & Plant Improvement Institute (SPII), AREEO, Karaj, Iran, which are gratefully acknowledged.

Ethical considerations

The authors avoided data fabrication, falsification, plagiarism, and misconduct.

Conflict of interest

The authors declare that they have no conflict of interest.