Evaluation of genetic diversity of phenomorphological traits and forage yield in different populations of Hordeum bulbosum L.

Introduction
Barley (Hordeum bulbosum L.) is low water requirements and very good resistance to cold and resistance to salinity. For the climatic limitations such as drought in Iran, the need to identify high-yielding genotypes and use them in breeding programs seems necessary. In plants, geographical separation causes variation in the genotype and phenotype of species populations, especially in habitats, environmental conditions, and historical and phylogenetic processes, which are the main drivers of phenotypic variation among individuals (Albarran-Lara et al., 2019). This study aimed to investigate morphology, phenology, and forage yield traits involved in the genetic diversity of different populations of the H. bulbosum. The results obtained from the present study are introduced for the development of new adaptable or high-yielding barley cultivars. High-yielding barley cultivars can be cultivated in different regions as forage for the development of rangelands.
Materials & Methods
In this study, 18 populations of Hordeum bulbosum L., were evaluated for morphological, phenological and forage yield traits. This study was carried out in 2022 at the Alborz Research Station, Karaj field. Field experiments were designed as a one-way analysis of variance (ANOVA) design with 3 replications. Eleven different quantitative traits were evaluated at harvest. Traits included: days to flowering, days to seed maturity (days to flowering and seed maturity were calculated when each plot was approximately 50% flowering and 90% seed maturity, respectively), plant height (at 50% flowering), internode length (at 50% flowering), number of internodes, number of tillers, spike length (cm), leaf length (cm), leaf width (cm), forage yield (plant fresh weight, g) and plant dry weight (g) (Arzani et al., 2010). Data analyzed by sing SPSS-19 and Minitab-16 software.
Results & Discussion
Clear significant variations for all traits were observed between populations (p < 0.01). Populations 11752 (Gilan, Roudbar), 18780 (Golestan), and population 40293 (Babajani, Kermanshah) were the high plants. Also, populations 11752 (Roudbar, Gilan) and 32930 (Kermanshah), produced more biomass per plant than other populations. Populations 11752 and 32930 had the longest days to flowering and maturity (65 and 130 days), and the shortest days to seed maturity (120 days) was in population 37323. In the principal component analysis (PCA), the first four components were able to explain more than 85% of the total trait variation. The values of the first four components were 33.5, 22, 18 and 11%, respectively. The first component was associated with plant height, plant fresh and dry weight, the second component with internode length and number, tiller number and spike length, the third component with leaf length and days to flowering and the fourth component with leaf width and days to maturity. Populations 11752 and 32930 were partially separated by the first component. The traits related to this separation are mainly plant height and yield traits (plant fresh and dry weight). A cluster analysis at a genetic distance of 8.40, resulted in four main clusters. The distribution of populations in the cluster is similar to their distribution in the PCA. The analysis also showed that the similarities of the populations extend beyond their geographical source of collection. Similar results observed in the findings of other researchers (Mekonnon et al., 2015).
Conclusion
Our findings indicate that different barley cultivars can be grown as forage in different regions with suitable fresh and dry forage yields to meet livestock needs. Populations 11752 (Rodbar, Gilan), 18780 (Golestan), and 24407 (Qom), produced tall plants, and two populations 11752 (Rodbar, Gilan) and 32930 (Kermanshah) were superior in terms of fresh and dry forage yields. Populations 11752 and 32930, for long and population 37323 (Kohkiluyeh and Boyer-Ahmad), for short growing season are recommended, respectively.
Keywords: Agronomic, Fresh and Dry Plant weight, Morphology, Plant height, Phenology