Genetic variability and trait associations insome Selected semi - dwarf tef [eragrostis tef (zucc.)Trotter] Recombinant inbred lines in central Ethiopia

Abstract

A field experiment was conducted to determine the extent of genetic variability and trait association among semi-dwarf tef recombinant inbred lines for yield and yield components with emphasis on lodging and thereby generate information as well as identify superior recombinant inbred lines. A total of fourty ninerecombinant inbred lineswere evaluated for 16 traits using simple lattice design at Holetta and Debre Zeit in 2017 cropping season. All the traits measuredover the locations showed highly significant differences among the recombinant inbred lines except fertile tiller per plant, while the inbred lines x location interaction effect was highly significant for most of the traits measured.Grain yield showed the highest phenotypic coefficients of variation (26.36%) followed by above ground biomass (23.16%), while the remaining traits showed low (<10%) to moderate (10- 20%). No highest genotypic coefficients of variation (>20%) recorded.However, moderate (10-20%) genotypic coefficient of variation was recorded for above ground biomass. Plant height and panicle length showed high heritability (>60%), whereas half of the remained traits showed low (<30%) and moderate (30% to 60%) heritability. Genetic advance as percent of the mean was the highest for above ground biomass (>17.02%) and least for number of branches per panicle (0.09%). Both the genotypic and phenotypic correlation coefficients showed positive association of grain yield with most traits. Lodging index showed negative phenotypic correlation with most lodging related traits and positive with grain yield as well as phenological traits. Path coefficient analysis revealed that above ground biomassexerted the highest positive genotypic and phenotypic directeffect on grain yield. Cluster analysis grouped the recombinant inbred linesinto four clusters based on their similarity. The highest inter-cluster distance noted between clusters II and IV while the lowest was between clusters III and IV.Principal component analysis showed that about 77.6% of the gross variance among recombinant inbred lines explained by five Principal components with eigenvalues greater than unity. Traits, which are closely associated with lodging such as plant height, culm length and diameters of the basal culm internodes have special interest in the improvement of tef.Of all the traits evaluated in this study, plant height, panicle length showed high H2 and aboveground biomass performs relatively high values of GCV, PCV and GAM. Therefore, these traits are important for selection and further improvements.This study revealed that four recombinant inbred lines had higher yield than local and standard checks.RIL#14 showed the highest grain yield and low lodging index, longer panicle, higher number of spikelets per panicle, as well as the highest above ground biomass than all recombinant inbred lines, which could be the base for future tef breeding program