Estimation of genetic correlations and co-heritabilities among morphological and seed retention in Panicum coloratum var. makarikariense

M. MAINA; L.V. ARMANDO; M.A. TOMÁS

Pergamino

Congreso; 9° Congreso Internacional de semillas forrajeras y céspedes; 2017

Panicum coloratum is a tropical grassadapted to a wide range of climatic conditions, with potential use as forage intropical and semi-arid regions around the world. No uniform development of thepanicle and low seed retention cause big loses at seed harvest. Breedingstrategies to increase seed yield requires a better understanding of therelationships between traits involved and detection of characters that mayfacilitate indirect selection. The objectives of this study were to estimatecorrelations and co-heritabilities between morphological characteristics thatmay allow improvement in seed retention by indirect selection. Thirteen progenies (half-sibfamilies) were spaced-planted in the field (INTA-EEA Rafaela 31°11'41'' S; 61°29'55''W) according to a randomized complete block design with five replications. Thenumber of reproductive tillers/plant (PN), flag leaf area (cm2,FLA), leaves number/reproductive tillers (LN), seed number/panicle (SN), seedweight/panicle (mg, SW) and percentage of seed retention (SR) at 30 days postanthesis, were measured on 15 genotypes per family from January to March 2010. Genetic, environmental andphenotypic correlations were estimated by analysis of variance and covariance,and co-heritabilities were calculated according to Ghesquière et. al 1994. Moderate andsignificant positive genetic, environment and phenotypic correlations werefound between FLA and LN (r=0.4), FLA and SW (r=0.3). Moderate but negativegenetic, environment and phenotypic correlations (r=-0.3) were estimated among SN and PN, SN and SR. The rest of the correlations were very low. The value ofco-heritabilities among FLA and PN was closer to the heritability estimated forFLA individually. The rest the values of co-heritabilities were insignificant. Giventhe difficulties in estimating seed retention in a plant, it would be desirableto find a way to make selection in an indirect way. However, none of the six morphologicalcharacters measured here would be suitable todo this.Nonetheless, the relatively good heritability found for seed retention (h2=0.55)might warrant good genetic gains by means of direct selection.