GENETIC VARIATION OF BARLEY GENOTYPES USING MORPHOLOGICAL, YIELD COMPONENTS AND MOLECULAR MARKERS

Genetic diversity can be investigated through different methods such as morphological traits, yield components, and molecular markers. This study assessed three local, Egyptian commercial varieties of barley (Giza 134, Giza 135 and Giza 136) as well as seven barley lines, morphologically during different growth stages (vegetative, flowering and maturity stages) and on molecular basis (based on ten ISSR markers). Two field experiments were carried out in Giza Research Station, Agricultural Research Center during 2019-2020 and 2020-2021 seasons. Morphological characterization was done based on 28 of morphological characters using the Internationally Recognized, Descriptor of the International Union for Protection of new Varieties (UPOV 2018). The results indicated that variation existed among, the genotypes for some morphological characters, and wasn't found in other characters such as lowest leaves hairiness of leaf sheaths, flag leaf, anthocyanin coloration of auricles, flag leaf intensity of anthocyanin coloration of auricles, flag leaf glaucosity of sheath, ear number of rows, grain husk, grain speculation of inner lateral nerves, of dorsal side of lemma, grain hairiness of ventral furrow, kernel color of aleurone layer and seasonal type). Plant height, tillers/m2, heading date, grain filling period, maturity, spikes/m2, main spike length, grain/ spike, weight grain/ spike, grain yield, biological yield, straw yield, seed index and harvest index showed significant, differences among the genotypes. Four of the promising lines (1, 2, 3 and 4) significantly, surpassed the check varieties and other lines in yield and its components. Ten ISSR primers were used to characterize the barley genotypes. The ISSR markers used were able to identify each of the ten genotypes by unique positive or negative markers. The ten genotypes amplified 24 unique markers, (23 positive and 1 negative marker). Giza-136 variety was characterized by 5 unique markers. The highest similarity index, was (Line 2 and Giza-134 variety) and between (Line 3 and Line 7), while, the lowest index between (Line 2 and Line 5). The ISSR-based dendrogram was divided into two main sub clusters at 0.75 similarity. The first main cluster comprised six genotypes, while the second one contained the other four genotypes. These results proved ISSR markers to be used as marker of choice to identify barley genotypes.