Morphological and physiological characterization of diploid and tretraploid forms of Trifolium riograndense in comparison with Trifolium repens and Trifolium polymorphum

Abstract

This experiment was conducted at the EEA/UFRGS, Guaíba, Rio Grande do Sul State, Brazil, from March 1983 to February 1984. Morphological and physiological characteristics of diploid and tetraploid forms of Trifolium riograndense Burkart were evaluated in comparison to T. repens L. and T. polymorphum Poir., using completely randomized blocks design with six replications. The rates of growth in diameter and height, rate of stolons growth, length of floral peduncle, duration of reproductive period, number of flowers per inflorescence, number of seeds per legume, seed production per plant, germination percentage, percentage of CP and in vitro DM digestibility were evaluated. White clover and T. polymorphum presented the highest and lower values, respectively, for most of the analyzed variables, while T. riograndense was intermediary. The 4x plants of T. riograndense were superior to 2x ones in the rate of growth in heigth (reproductive period) and floral peduncle length and inferior in the rates of growth in diameter (vegetative and reproductive periods) and stolons growth. Regarding the other characteristics no significant differences between 2x and 4x plants were detected. All the species presented good forage quality measured by CP and in vitro DM digestibility percentages.