Background: Naked barley is a traditional, climate-resilient and highly nutritious crop of the high mountains of Nepal. Knowledge of agro-morphological diversity among the naked barely genotypes is fundamental for their efficient utilization in plant breeding schemes and effective conservation programs. The primary objective of this study is phenotypic characterization and diversity assessment of naked barley landraces in Nepal for pre-breeding purposes. Methodology: Data on quantitative and qualitative traits of 25 naked barley landraces from diversity blocks established across the four mountainous locations of Nepal (Humla, Jumla, Dolakha and Lamjung) were subjected to calculation of descriptive statistics and multivariate analysis (UPGMA cluster analysis/principal component analysis). Frequency distribution of various categories of qualitative traits and Shannon-Weaver diversity indices were computed. Results: The UPGMA cluster analysis using both quantitative and qualitative traits individually categorized the 25 naked barley landraces in five clusters in each case with no distinct regional grouping patterns in such a way that the landraces from same or adjacent regions of origin and collection amassed in different clusters. NGRC04894, Lamjung Local, NGRC02306, NPGR1579, NGRC02327 and NPGR1579 exhibited morphoagronomical superiority and potentiality for utilization as genitors in crop improvement programs. Principal component analysis revealed the quantitative traits, viz. grain yield, plant height and earliness, and qualitative traits, viz. grain color, overall phenotypic performance, lemma awn/hood and lemma awn barbs, to be the principal discriminatory characteristics of the Nepalese naked barley landrace collection. The Shannon-Weaver diversity index (H′) ranged from 0.32 to 0.99 with a mean value of 0.73, inferring tremendous diversity in the collection for the qualitative traits. Conclusion: The marked diversity observed among the Nepalese naked barley landraces could be utilized in crop improvement for various traits. The information generated complements the robust breeding program of competitive, stable and climate-resilient varieties of end users' preferences in different mountainous agro-ecologies and also bolsters the employment of innovative and proven participatory plant breeding approach using diversity kits and informal research and development kits to expand and promote the varietal choice options for expeditious benefits to the farmers in the high mountains, considering that only one naked barley variety, viz. Solu Uwa, has been released in Nepal to date.

Naked barley (Hordeum vulgare var. nudum L.) is an important food crop in mountain regions of Nepal, however, its production area and genetic diversity is known to be shrinking fast. One of the reasons could be the poor productivity. To improve the productivity of crops, it is essential that new site-specific, high-yielding and widely adopted varietal options for farmers should be developed for sustainability. To identify the varietal responses to environment, multi-location testing is one of the main tools. Following this, we evaluated agronomic performance of eight naked barley landraces collected from five different locations of Nepal with altitude ranging from 1370 to 2500 meter elevations from the sea level during the winter season of 2014/15 in order to assess the landraces adaptability across different locations. Combined analysis of variances revealed that NGRC02306, NGRC04902 and NGRC04894 were the high yielding landraces. The landrace namely NGRC04894 was found the most stable genotype with better adaptability to all tested environments whereas NGRC02306 and NGRC04902 were high yielding landraces adapted to high yielding environment namely Khumaltar. However, the lower yielding landrace NGRC02327 was the earliest and could be preferred by farmers as its maturity allows it to fit better in the rice based cropping system. Our study showed that these landraces need to be verified further in farmers’ fields and the release of one or more of them would help to diversify the genetic base of naked barley varieties in the seed supply system.