بررسی تنوع ژنتیکی ارقام پیازبا استفاده از نشانگرهای مولکولی در ارتباط با مقاومت به پوسیدگی فوزاریومی ریشه و طبق

In this research, RAPD, ISSR and SRAP markers were used to evaluate the genetic diversity of eighteen
different onion genotypes with different levels of resistance to Fusarium root and basal rot disease,
Fusarium oxysporum f.sp. cepae. The results showed that the average polymorphism between RAPD
primers varied from 56 to 82%, ISSR from 61 to 82%, and SRAP from 56 to 76%. Overall, by evaluating
MI, PIC, I and H indices among ISSR primers, ISSR1 and ISSR10 primers. SRAP primers, SRAP1 and
SRAP6 primers and among RAPD primers, RAPD3 and RAPD4 primers showed the best performance
in examining the genetic diversity of the target onion populations. There was a significant correlation
between the dendrograms produced based on the similarity matrices. The classification pattern in the
dendrograms showed a relative correlation with the disease severity grouping. So that in all the three
markers studied, Saba and Saba-HS genotypes are among the most resistant genotypes to Fusarium root
and basal rot disease and located to one branch, and Golden Eye and Sahar-HS genotypes are the most
susceptible genotypes to this disease in another branch separately. Of course, in confirmation of this
issue, defense related marker genes and enzymes were also investigated, which were significantly
increased in the corresponding resistant cultivars compared to the susceptible onion cultivars. These
findings introduce new onion genotypes resistant to this disease and also they can be used to select
disease-resistant onions in breeding programs to reduce the severity of the onion Fusarium root and rot
basal rot disease.