Identification of ISSR Markers for Studying the Biodiversity of Bulgarian Representatives of GenusOrobancheSubsectionMinores

Identification and genetic diversity analysis of broomrape in Xinjiang, China

BACKGROUND

As a holoparasitic weed, broomrape has seriously threatened the production of economically important crops, such as melon, watermelon, processed tomato, and sunflower, in Xinjiang in recent years. However, the distribution and genetic diversity of broomrape populations in Xinjiang are not clear at present, which hinders their prevention and control. The purpose of this study was to identify the main species and the genetic differentiation structure of the broomrape population in Xinjiang.

METHODS AND RESULTS

In the present study, 93 samples from different geographic regions of Xinjiang were collected to identify the species based on ITS and plastid rps2 regions, and the samples were also used to analyze the genetic diversity based on ISSR markers. The results showed that broomrape is not monophyletic in Xinjiang and consists of two major clades (Orobanche cf. aegyptiaca and O. cernua) and three subclades (O. cf. aegyptiaca var. tch, O. cf. aegyptiaca var. klz, and O. cernua.var. alt) based on phylogenetic analysis. Furthermore, the results of the genetic diversity analysis indicated that the average polymorphic information content and marker index were high values of 0.58 and 7.38, respectively, showing the efficiency of the ISSR markers in detecting polymorphism among the broomrape population studied. Additionally, the 11 selected primers produced 154 repeatable polymorphic bands, of which 150 were polymorphic. The genetic diversity of the samples was 37.19% within populations and 62.81% among the populations, indicating that the main genetic differentiation occurred among the populations. There was less gene exchange between populations, with a gene flow index (Nm) of 0.2961 (< 1). The UPGMA dendrogram indicated that most populations with similar geographical conditions and hosts were clustered first, and then all samples were separated into two major groups and seven subclusters.

CONCLUSION

The broomrapes are mainly O. cf. aegyptiaca and O. cernua in Xinjiang, which were separated into two major groups and seven subclusters based on ISSR markers. Our results provide a theoretical basis for breeding broomrape-resistant varieties.

Molecular Characterization of Broomrape Populations from Republic of Moldova using SSR Markers

The genetic diversity study of 39 broomrape populations from the Republic of Moldova was performed using 12 highly polymorphic SSR primer pairs, which shown the high level of polymorphism (average PIC value 0.57). We found that some of the SSR primers (Ocum-59 and Ocum-108) produced polymorphic bands suitable for discrimination between the studied populations. The diversity analysis within broomrape populations revealed a higher number of detected alleles and heterozygous loci in the accessions from the Southern region when compared to the Northern and Central ones. The average PIC values for the Northern, Central and Southern accessions ranged from 0.43, 0.48 to 0.56, respectively. Some populations from the Southern region (especially, Carabetovca, Alexanderfeld, Stefan-Voda and Slobozia Mare) have shown the major differences in the profiles obtained and presented the high level of genetic variability. The dendrogram based on genetic distance divided the 39 broomrape accessions into twelve clusters. High variability of