Genetic variation and evaluation of exotic barley (Hordeum vulgare L.) genotypes for grain protein content, starch content and agronomic traits

A set of 45 genotypes comprising of hulled and hulless type barley from ICARDA along with 6 check varieties (DWRUB52, DWRUB64, DWRB73, BH902, RD2035 and RD2552) was evaluated  in an augmented design for grain protein content, starch content and agronomic traits during rabi season of 2013-14. Based on mean performance, grain protein content had a wide range of variation from 11.03-18.39% with a mean value of 12.90%. Genotype IBYT-MRA-4 had significantly higher grain protein content (18.39%) than best check RD2552 (11.78%) followed by INBYT-17 (17.89%), IBYT-LRA-M-8 (16.53%), IBON-LRA-M-52 (15.73%), IBYT-MRA-1(15.59%), IBYT-MRA-10 (15.29%), INBON-51 (15.11%) and IBYT-LRA-C-13 (14.94%). Out of these, two genotypes namely INBYT-17, INBON-51 were hulless types and can be used for improvement of food barley varieties for protein content.  Starch content had a mean range values from 57.76-64.31% with a mean value of 61.21%. A hulless barley genotype namely INBON-39 was identified which had significantly higher starch content (64.31%) than best check DWRB73 (62.58%) along with more tiller number and ear length. High heritability along with high genetic advance for grain yield, thousand grain weight, ear length and grain filling period showed that these traits are under control of additive genes and hence, can be improved by selection based on phenotypic performance. Grain protein content had a negative correlation with starch content (r = -0.69) and grain yield (r = -0.39), hence simultaneous improvement for high grain protein, high starch content and high grain yield is difficult to achieve and suitable breeding strategy needs to be investigated.