Wild populations of Dactylis polygama H. for the formation of genetic collection and breeding

Abstract

Much effort has been made recently to expand the range of species suitable for modern farming. More efficient utilisation of the available genetic resources is one of the ways to achieve this purpose. Much attention has been drawn to Dactylis polygama H. which is a promising specines for forage. The species has not yet been domesticated. The present study was designed to estimate the feasibility of wild D. polygama H. Population inclusion in breeding programmes. With this end in view, we compared traits of D. polygama H. population and widely grown cocksfoot (D. glomerata L.) by the conventional agrobiological assessment method (in points) and estimated polymorphism by the DNA fingerprint method. D. polygama H. population was found to consist of plants differing in ploidy, therefore they were divided into two forms: diploid (2n = 14) and tetraploid (2n = 28). Comparison of their agrobiological traits with those of the D. glomerata L. variety ‘Asta’ (2n = 28) revealed that wild populations produced a lower herbage yield and were later-maturing but accumulated higher contents of crude protein and water-soluble carbohydrates and were characterised by better digestibility properties. Comparison of traits of D. polygama H. populations suggests that the tetraploid plants surpass the diploid form in a number of characteristics (leaf width, regrowth rate in spring, plant height and herbage yield, the number of inflorescences, protein content). The diploid form accumulated less protein and lower contents of all fibre fractions. It is noteworthy that the diploid population had a lower content of fibre and a higher content of water-soluble carbohydrates which have a positive effect on dry matter digestibility. Although PCR was performed with seven simple sequence repeat primers, only the GO3, GO7, UBC824 primers were suitable for genomic DNA amplification. In DNA fingerprints, there were produced 23 fragments, of them 8 (34.8%) were polymorphic. The fragment sizes covered the 400–1500 bp range. Individuals of the tetraploid form showed no genetic diversity, whereas DNA fingerprints of diploid plants varied – primers GO7 and UBC824 generated 4-type DNA fingerprints. There were also DNA fragments specific to diploid and tetraploid forms of D. Polygama H. plants. Keywords: Dactylis polygama H., ploidy, agromorphological traits, ISSR fingerprinting, genetic diversity