Genetic variation and interrelationships among agronomic traits in Egyptian bread wheat landraces and local cultivars

Abstract EN

The aim of this work was to investigate the genotypic variation of thirty five bread wheat genotypes as well as to clarify the association between grain yield and the other important agronomic traits.

Two field experiments were carried out in the Experimental Farm of Genetic Resources Department, Bahteem Agricultural Research Station, Egypt during 2015-2016 and 2016-2017 growing seasons.

Thirty two wheat landraces collected from eleven Districts in Egypt, in addition to three local cultivars were evaluated for earliness traits, plant height, yield and its components.

The results indicated significant differences among the evaluated wheat genotypes for all investigated traits during the two seasons.

The highest grain weight/plant and contributing traits were assigned for genotypes; G3, G8, G18, G27, G29, G33 and G35 at two growing seasons.

The phenotypic variance (σ²_ph) was found slightly higher than the genotypic variance (σ²_g) for all studied traits under two seasons, and accordingly, phenotypic coefficient of variation (PCV) values were relatively greater than genotypic coefficient of variation (GCV) values for all traits.

Heritability in broad sense (h²b) values were high for plant height (90.63 and 97.81 % ), number of grains/spike (95.33 and 84.66 % ), 1000-grain weight (76.42 and 84.03 % ), days to heading (77.4 and 87.06 % ) and days to maturity (86.18 and 66.56 % ) in 1^st and 2^nd seasons, respectively.

Besides, it was low in 1^st season (43.38 % ) and high in 2^nd season (71.91 % ) for grain weight/plant, whereas it was moderate for number of spikes/plant (52.87 and 58.09 % ) in 1^st and 2^nd seasons, respectively.

Furthermore, positive genotypic and phenotypic correlations were found between studied traits and grain weight/plant during two growing seasons except days to heading.

Additionally, path analysis was calculated and it was found that the direct effects on wheat grain yield of all studied traits were positive in both seasons except days to 50% heading at two seasons and days to maturity and plant height at the second season.