“Morphological and molecular evaluation of Panicum coloratum L. var. makarikariensis Goossens”

ARMANDO, L; GARAYALDE AF; TOMAS A; CARRERA A

Buenos Aires

Congreso; The 6th Internatiionall Symposiium on Mollecullar Breediing of Forage and Turf MBFT 2010; 2010

Panicum coloratum is a warm-season allogamous perennial bunchgrass native to South-Africa, introduced to several countries for pasture improvement. The var. makarikariensis tolerates seasonal flooding and drought and maintains above-average forage quality. In Argentina, scarce information has limited its use and delayed its incorporation into germplasm collections. Our objective was to analyse the phenotypical and molecular (ISSR) variability of var. makarikariensis and compare it with variety coloratum. Fifty-one individuals from var makarikariensis (BR, DF and IFFIVE) and var. coloratum (CH) were evaluated. Variables were panicles number, length and width of flag leaf, seed weight and leaf elongation rate. Principal Components and Principal Coordinates analyses were utilized for quantitative variables and molecular data. Differences among populations were evaluated through ANOVA and AMOVA. A Mantel test was performed to examine matrices correlations. ANOVA and AMOVA showed significant differences among populations for all phenotypical (p<0.05) and molecular (p<0.001) data. From 42 ISSR loci, 41 were polymorphic (97.6%). Genetic variability was highest in IFFIVE and DF population (He=0.140;P=35.71% and He=0.137;P=33.3% respectively) and lowest in BR and CH (He=0.072;P=16.67% and He=0.099;P=26.19%, respectively). Private bands were found in all populations. First two PCA axes explained 71.5% of total variation; individuals were localized in relatively well defined groups according to population of origin. Panicle number, length and width of flag leaf and seed weight were the most informative variables to distinguish between varieties. The groups were better defined in PCO (first two axes explained 82.6%). Both analyses showed a clear differentiation between varieties. IFFIVE individuals were more dispersed than DF and BR. Correlation was positive between phenotypical and molecular matrices (r=0.643,P<0.001). Mantel test and multivariate analyses suggested congruent patterns of phenotypical and molecular variation. This study suggests significant level of genetic variability and represents a novel contribution to the characterization of P. coloratum var. makarikariensis to be included in germplasm collections and breeding programs.