مجله بیوتکنولوژی کشاورزی (May 2023)
Investigating the genetic diversity of saffron (Crocus sativus L.) corms induced by gamma ray irradiation using the SCoT marker
Abstract
Objective Due to its sterility, saffron reproduces only asexually and for this reason, except for some spontaneous mutations, other genetic changes do not occur naturally in it. Therefore, induced mutations can act as a suitable method to create diversity in the genetic structure of the plant and improve its growth, performance and quality characteristics. The present study was conducted to investigate the genetic diversity of irradiated saffron plants compared to control samples (without irradiation) using the SCoT markers. Materials and methods Healthy saffron corms were grown in the greenhouse along with control corms at two levels of 15 and 18 Gy gamma rays’ radiation and immediately after irradiation. In order to investigate the created genetic diversity, after extracting DNA from the leaf sample and determining the quality and quantity of the extracted DNA using the nanodrop device, out of the 30 SCoT primers used, 9 primers were finally analyzed for this study. Results A total of 46 strips were scored, 31 strips had polymorphism, so that the highest number of polymorphic strips was related to SCoT05 (6 strips) and the lowest number was related to SCoT04, SCoT11 and SCoT12 (2 strips). The average percentage and Polymorphic Information Content (PIC) were 67.13 and 0.35, respectively, and the highest polymorphic content was related to SCoT11 and SCoT17 (0.45) and the lowest was related to SCoT13 (0.13). SCoT17 (0.33) had the highest Marker Index (MI). Based on the results of the Jaccard’s similarity coefficient matrix, the range of changes varied from 0.45 to 0.88 and its average was reported as 0.70. The results of cluster analysis also showed that two control samples in the first cluster, 3 out of 4 irradiated with 15 Gy dose in the second cluster, and except for 18G105 irradiated which was placed in a separate cluster, the other 18 Gy radiation along with 15G132 irradiated from the 15 Gy level were grouped in a cluster. The most observed alleles (Na) were estimated in the 15 Gy treatment (1.55) and the lowest in the control (1.2767). The amount of diversity in the population of 15 Gy based on Shannon and Ni indices (I=0.2061 and He=0.3064) was more than control and 18 Gy. Conclusions The results showed the high efficiency of SCoT17 in the incidence of polymorphism among irradiated and control samples of saffron. Molecular variance analysis (AMOVA) evaluated the diversity within groups more than between groups. In addition, the difference in the band pattern of SCoT markers, the clustering pattern and the genetic distance showed the usefulness of gamma irradiation and the efficiency of mutagenesis to create diversity in the saffron plant.
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