A multilevel exploration of Avena strigosa diversity as a prelude to promote alternative crop.

BACKGROUND: Sand oat (Avena strigosa Schreb.), one of the four cultivated species of the genus Avena, could be considered as another alternative crop. In gene banks 865 germplasm samples of this species have been preserved that have not been thoroughly investigated so far. The results of phenotyping (36 traits), isoenzymatic (12 systems) and genetic (8 pairs of Sequence-related amplified polymorphism markers) variation were used to obtain the complete description of 56 accessions diversity originated from different parts of world. RESULTS: Breeded and weedy forms represented similar pool of morphological traits that indicated a short-term and extensive breeding process, albeit all accessions which we classified as cultivated were characterized by better grain and green mass parameters compared to the weedy ones. Isoenzymes showed relationships with geographical origin, which was not possible to detect by SRAP markers. There was no similarity between morphological and biochemical results. The polymorphism level of SRAP markers was lower than indicated by the available literature data for other species, however it may result from the analysis of pooled samples of accessions with a high internal variability. The extensive type of breeding and its relatively short duration was also reflected in the population structure results. Joint analysis revealed that a secondary centre of diversity is being created in South America and that it has its genealogy from the Iberian Peninsula. CONCLUSIONS: Despite the relatively large representation of this species is in various gene banks, it is highly probable that the vast majority of stored worldwide accessions are duplicates, and the protected gene pool is relatively narrow. Sand oat meets all the requirements for an alternative crop species, but further studies are needed to identify the genotypes/populations with the most favourable distribution of utility and quality parameters.

Promoting the Use of Common Oat Genetic Resources through Diversity Analysis and Core Collection Construction.

The assessment of diversity and population structure and construction of a core collection is beneficial for the efficient use and management of germplasm. A unique collection of common oat landraces, cultivated in the temperate climate of central Europe until the end of the twentieth century, is preserved in the Polish gene bank. It consists of 91 accessions that have never been used in breeding programs. In order to optimise the use of this genetic resource, we aimed to: (1) determine genetic and agro-morphological diversity, (2) identify internal genetic variation of the tested accessions, (3) form a core collection and (4) recognise the accessions useful for breeding programs or re-release for cultivation. The collection was screened using ISSR markers (1520 loci) and eight agro-morphological traits. Uniquely, we performed molecular studies based on 24 individuals of every accession instead of bulk samples. Therefore, assessment of the degree of diversity within each population and the identification of overlapping gene pools were possible. The observed internal diversity (Nei unbiased coefficient) was in the range of 0.17-0.31. Based on combined genetic and agro-morphological data, we established the core collection composed of 21 landraces. Due to valuable compositions of important traits, some accessions were also identified as useful for breeding programs. The population structure and principal coordinate analysis revealed two major clusters. Based on the previous results, the accessions classified within the smaller one were identified as obsolete varieties instead of landraces. Our results show that the oat landraces are, in general, resistant to local races of diseases, well adapted to local conditions and, in some cases, yielding at the level of modern varieties. Therefore, in situ conservation of the landraces in the near future may be satisfactory for both farmers and researchers in terms of the genetic resources preservation.

Hybrid breeding of Pampa-cytoplasmic triticale based on crosses with rye.

The first series of field experiments with triticale F1 hybrids from 2009 confirmed usefulness of the rye 'Pampa' cytoplasmic system of mass crossing control in hexaploid (2n = 42 = AABBRR) winter triticale. The level of fertility restoration in 30 F1 hybrids varied within a range of 35.1% - 91.3%. However, the top F1 yield has not exceeded 92% of the check cultivar 'Moderato'. In the next series of field experiments with four winter F1 hybrids from 2012 the best yield reached 102% of the 'Moderato' standard and the fertility restoration index ranged between 16.7% and 100%. The top yielding F1 combination was produced using a male line derived from a cross with a restorer line from rye hybrid breeding. It supports the idea of using rye hybrid breeding as a source of variation in hybrid breeding of triticale. The advanced rye lines, representing well established complementary gene pools, show not only high potential for heterosis, but also high level of compensation for negative side effects of the 'Pampa' cytoplasm on plant vigor, which seems important in triticale. The gene flow from rye female and male gene pools to those of hexaploid triticale is facilitated with tetraploid triticale x diploid rye crosses. Numerous triploid F1 hybrids with relatively high fertility are produced, which are able to set seed after spontaneous pollination with hexaploid triticale.