Integrating DUS descriptors and phenol colour tests for comprehensive characterization and varietal identification of barley genotypes

Abstract

Barley (Hordeum vulgare L.) is one of the important cereal crops which is cultivated as rabi crop in northern part of India viz., Haryana, Punjab, Himachal Pradesh, Rajasthan, Uttar Pradesh, Bihar and Madhya Pradesh. Barley is favoured as a dual crop, due to its ability to grow well in marginal soils, robust fodder properties, abundant foliage growth, ability to regenerate and modest grain yield. It is vital to understand the prevalent morphological diversity of barley to increase the selection efficiency of breeding materials with varied genetic backgrounds. Characterization and varietal identification of cultivars and genetic purity of the seed lots are pivotal for varietal improvement, varietal protection, and quality seed production. Further, several chemical tests for classifying genotypes may complement varietal identification and characterization and management of genetic resources. Considering this, morphological descriptors and phenol tests were used for distinguishing different barley genotypes during rabi 2021-22. In toto, twenty-five morphological descriptors were studied in 102 barley genotypes wherein forty genotypes were subjected to phenol colour test and modified phenol test (CuSO₄ & Na₂CO₃). Phenol testes were effective in categorising barley genotypes based on colour reaction in to four groups i.e. deep olive colour, light brown colour, brown colour, and black colour. Among forty genotypes, only one genotype i.e. Kedar showed black colour reaction upon exposure to phenol test. While, six genotypes showed brown colour and twelve genotypes showed light brown colour and twenty-one genotypes developed deep olive colour reaction. However, number of genotypes showing black colour reaction increased to four (Alfa 93, Dolma, Kedar, BHS352) and six (Alfa93, RD2592, Dolma, Raj Kiran, Kedar, BHS352) upon pre-soaking in CuSO₄ and Na₂CO₃ as compared to phenol test. Therefore, integration of phenol tests with morphological descriptors facilitates characterization and identification of barley genotypes.