Rhododendron is well-known for the colorful corolla. Molecular marker systems have the potentials to elucidate genetic diversity as well as to assess the genetic fidelity in rhododendrons. In the present study, the reverse transcription domains of long terminal repeat retrotransposons were cloned from rhododendrons and used to develop inter-retrotransposon amplified polymorphism (IRAP) marker system. Subsequently, 198 polymorphic loci were generated from the IRAP and inter-simple sequence repeat (ISSR) markers, of which 119 were derived from the IRAP markers. It was justified that in rhododendrons, IRAP markers were superior to the ISSRs in some polymorphic parameters such as the average number of polymorphic loci (14.88 versus 13.17). In comparison with the single one, the combination of IRAPs and ISSRs systems was more discriminative for detecting 46 rhododendron accessions. Further, IRAP markers demonstrated more efficiency in genetic fidelity detection of in vitro R. bailiens, an endangered species just recorded in Guizhzhou Province, China. The available evidences revealed the distinct properties of IRAP and ISSR markers in the rhododendron-associated applications, and highlighted the availability of highly informative ISSR and IRAP markers in the genetic diversity evaluation and the genetic fidelity assessment of rhododendrons, which may facilitate the preservation and genetic breeding in rhododendron plants.

Genetic diversity is inevitable in making any crop improvement program successful. DNA fingerprinting technology to assess the genetic relationship among the selected genotypes for identification and cataloging of different species and cultivars of roses is a promising tool for Rosa genomes. The inter-simple sequence repeats markers (ISSRs) were used to investigate the genetic diversity among twenty-one diverse Rosa genotypes belonging to two different species, Rosa hybrida and R. damascena, and three distinct groups of rose varieties, namely Hybrid Tea, Floribunda, and Damask roses. Twenty-four ISSR primers yielded a total of 280 scorable amplified fragments from 250-1800 bp in length, from which 244 were polymorphic, resulting in an average of 86.4% polymorphism. UPGMA cluster analysis based on Jaccard’s pairwise similarity coefficient values ranged from 0.264 to 0.818, clearly distinguished different species and genotypes, grouping them into three distinct clusters. The results confirmed a high degree of variation in the rose germplasm studied highlighting the potential of improvement in roses for the ornamental and perfume industry.

. Colchicine (C22H25NO6) is a substance used for inducing mutations in order to regulate important agronomic traits. The objective of this study was to investigate the effect of different concentrations (0.0, 0.04, 0.06, 0.08 and 0.1%) and treatment time (6, 12 and 24 h) of colchicine on agronomic traits of proso millet (Panicum miliaceum L.) and to assess the genetic diversity of M2 generations using inter simple sequence repeat markers (ISSR). The experiment was conducted in 2021 for the M1-generation and in 2022 for the M2-generation, from May to September. The percentage of the field germination was decreased with the increasing colchicine concentration and exposure duration. The chlorophyll-defective M1-M2 plants were obtained using various concentrations and exposure periods of colchicine. The highest amount of mutational modifications was attained at 0.08-0.1% concentrations colchicine. A total of 248 plant families with chlorophyll-defective mutations based on the research results were selected from 2214 families. The growing season of M1- and M2 plants were diminished under higher colchicine concentration (0.08-0.1%) combined with soaking time. Thus, the highest indicator of growing season (84 days) was observed at six h treatment time for PI 289324, while the fewest (78 days) was recorded at 12 and 24 h. The possibility of obtaining morphological mutations using colchicine has been confirmed. The ISSR primers amplified a total of 1333 fragments, 1281 bands were found to be polymorphic and 52 bands monomorphic. The percentage of polymorphism varied from 80 to 100 % with an average of 96.11%. Our results showed that most of the bands were found at 0.08% colchicine concentration. These positive variations are a great opportunity to use colchicine as a tool for improving agronomic traits in plant breeding.

In order to explore the genetic diversity of the extremely small population wild plant Habenaria dentata and protect and optimize its wild resources. The genetic diversity of 133 samples from 6 wild populations of H.dentata was analyzed by ISSR molecular marker technique to provide a scientific basis for the screening of improved germplasm resources. The results show that the average number of alleles (Na) was 1.765, the average number of effective alleles (Ne) was 1.424, the average Nei 's gene diversity index (He) was 0.252, the average Shannon information diversity index (I) was 0.381, and the average percentage of polymorphic loci (PPL) was 76.499%. The variation within populations was 77.34%, and the variation between populations was 22.66%. Gene flow (Nm) was 1.705 8, greater than 1. The results of cluster analysis showed that the six populations were mainly divided into four branches and not classified according to geographical location. There was no significant correlation between geographical location and genetic distance between populations (r=0.557, P>0.05). The genetic diversity of H.dentata is high. Among the six wild populations, the genetic diversity of Mulun population is the highest and this population can be used as a key protection unit.

Morphological features and composition of ISSR DNA fragments were studied in species of the genus Tulipa L. A comparative analysis of the data obtained was carried out and an attempt was made to clarify the species belonging of plants. Plants obtained from various sources were studied. It was found that representatives of the genus Tulipa L. from the two subgenera Tulipa and Eriostemones are well separated not only morphologically, but also by the composition of ISSR fragments. At the intra- and interspecific level, the results for morphological traits and molecular data differed. Interspecific and intraspecific differences were more clearly traced in the complex analysis of morphological features and ISSR PCR data. All samples obtained in the form of bulbs and renewed vegetatively had an identical set of ISSR fragments. Plants grown from seeds were characterized by a significant variety of molecular markers and had both species-specific and in-dividual genetic variability. It was found that the samples obtained and registered as the Tulipa urumiensis Stapf are the yellow-flowered form of the Tulipa tarda Stapf, and a sample received as the Tulipa turkestanika Regel is the Tulipa bifloriformis Vved. Thus, a comprehensive study of both the data of fragmentary DNA analysis and morphological features, provided a sufficient number of DNA samples, makes it possible to clarify the species of tulip plants, and also allows us to assess the genetic diversity of the genus Tulipa.