Varation of Genetic and Molecular Parameters of Barley Cultivars Effected by Seeding Rate

Abstract

Two experiments were carried out in this study , one of them was a field experiment established in the College of Agriculture - University of Anbar, and the second one was laboratory experiment. A field experiment was conducted during winter season 2021-2022 in the research station on. 1 , College of Agriculture – University of Anbar was carried out based on Split Plots arrangement according to randomized complete block design (RCBD) with three replications, the main plots included three seeding rates (120, 160 and 200) Kg ha-1, while the sub plots included five barley cultivars (Iba 256, Iksad 617, Amal, Samir and Buraq). Obtained results showed the following: -Seeding rate of 120 Kg ha-1 was significantly superior in the flag leaf area and spike length (14.45 cm2 and 7.53 cm respectively), while the seeding rate of 200 Kg ha-1was significantly superior in the plant height, flag leaf area, crop growth rate, early flowering and grain filling duration, weight of 1000 grains, biological yield and total yield (13.76 g m-2 day-1, 48.21 g, 20.74 Mg ha-1 and 5.78 Mg ha-1 respectively), whereas the seeding rate of 160 Kg ha-1was significantly superior in the number of tillers, harvest index, number of spikes, number of grains per spike and grain yield which reached values of 560.5 tiller m-2, 28.87%, 310.5 spike m-2, 44.42 grain spike-1 and 5.58 Mg ha-1 respectively. - The barley cultivars were significantly differed in the most studied traits, Buraq cultivar gave the highest mean of flag leaf area, crop growth rate, spike length, number of grains per spike and biological yield which reached 13.86 cm2, 14.85 g m-2 day-1, 7.39 cm, 48.46 and 21.95 Mg ha-1 respectively, while Iksad 617 cultivar gave the highest mean of acceleration of the flowering, number of tillers, number of spike, day to physiological maturity and grain yield (115 days, 558.5 tiller m-2, 347 spike m-2, 146.2 days and 6.01 Mg ha-1 respectively). Amal cultivar gave the highest mean of the weight of 1000 grains, grain filling duration and plant height (53.39 g, 36.3 days and 91.9 cm respectively), while Iba 256 cultivar gave a highest mean of harvest index (34.68%). - The traits of yield and its components of barley were studied in terms of performance and variances. The values of genetic and environmental variances, genetic and phenotypic coefficients variance, broad-sense heritability , environmental, phenotypic and genetic correlations and path coefficient were calculated. The highest proportions of the genetic to environmental variations were 67-time for weight of 1000 grains, as the highest ratios of heritability for biological yield and weight of 1000 grains were (99.28 and 98.54% respectively). The RAPD parameters were used to evaluate the genetic divergence between five barley cultivars and 12 primer were used. The primers produced 115 bands and the total polymorphic bands was 9.6% The A20 primer gave the highest percentage of polymorphic bands , which was 84.6% and the highest primer discriminatory power (11.9%). Depending on the data of the molecular parameter and the genetic similarity by UPGMA method in the linkage scheme, the cultivars were separated into two main groups, the first group contains Iba 265 cultivar, while the second group contains other cultivars according to the nearest neighbor method. The lowest genetic similarity (the highest genetic divergence) was between the cultivars Iba 265 and Samir, which was 0.40 and between the cultivars Iba 265 and Buraq 3d.0 de 8.51 , whereas the highest genetic similarity (the lowest genetic divergence) was 0.80 between the two cultivars Amal and Buraq.