Genetic variation, heritability and interrelationships of agro- morphological and phenological traits in Jordanian durum wheat landraces

Abstract EN

Nine hundred and twenty lines of durum wheat landraces collected from ten locations in Jordan and seven checks (Haurani 27, Acsad 65, Om Qais, Sham 3, Sham1, Sham 5 and Deiralla 6) were evaluated under field conditions in two contrasting environments (semi-arid and arid conditions) on the basis of single head row progeny.

The objectives were to estimate phenotypic (PCV) and genetic (GCV) coefficients of variation, broad sense heritability (h2) and genetic advance (GA) using the variance components method based on the combined analyses over locations and the variance analyses for each location for various agro-morphological and phenological traitsand to determine the interrelationships among these traits.

Because of high genotype × location (G × L) interactions, estimates of GCV, h2 and GA for different traits using combined analysis were generally lower than the estimates computed from the variance analyses made separately for each location.

The high cross-over G × L interactions could affect selection efficiency since lines selected under optimum growing conditions do not always perform well under poor conditions and vice versa, recommending to have perform selection for each target environment.

Intermediate to high estimates of PCV, GCV, h2 and GA (as % of the mean) were observed for grain yield plant-1 (GYP), biological yield plant-1, straw yield plant-1, number of spikes plant-1 (NSP), number of kernels spike-1 (NKS), hundred kernel weight (HKW) and average spike weight (ASW).

NSP, NKS, HKW and ASW were positively correlated with GYP, indicating possibility for improvement of wheat landraces by indirect selection for NSP, NKS, HKW and ASW.

Moreover, grain yield exhibited weak negative correlation with days to heading, days to maturity and grain filling period, showing the importance of earliness under drought stress conditions.

Several lines differed statistically from the checks, indicating the possibility of their use in a breeding program to improve different agro morphological traits.

In conclusion, this study indicates that the improvement of the Jordanian wheat landraces may be possible either through indirect selection for yield components or direct selection for grain yield per se.