Aneuploidy in induced autotetraploid populations ofFestuca pratensis, Lolium multiflorum, and Lolium perenne IV. Competitive interactions between euploid and aneuploid plants in a simulated perennial sward of tetraploid Festuca pratensis

Abstract

Klinga, K. 1987. Aneuploidy in induced autotetraploid populations of Festuca pratensis, Lolium muitiflorum, and Lolium perenne. IV. Competitive interactions between euploid and aneuploid plants in a simulated perennial sward of tetraploid Festuca pratensis. —Hereditas 107 249–256. Lund, Sweden. ISSN 0018–0661. Received August 5,1987 The competitive interactions in dense perennial stands of autotetraploid Fesruca pratensis were investigated by studying the following factors: (a) the persistence of euploid and aneuploid plants in pure stands and in mixtures; (b) the productivity of the persisting euploid and aneuploid plants in pure stands and mixtures; (c) the dry yield per unit area in the different kinds of growing regimes. About 80 % of the original euploid plants in the mixtures and about 50 % in the pure stands were left at the end of the experiment. The persistence of aneuploids did not differ between the two growing regimes. The aneuploid frequency changed from about 30 % to 20 % during the experimental period. In terms of persistence the euploids were better competitors, displayed by the significantly higher persistence in the mixtures. The yielding capacity and the competitive ability of individual euploids in the mixtures exceeded the aneuploids the year of planting and the first summer of the sward development. Later, the yielding capacity did not differ between the two chromosome categories. The negative agressivity values in the last year of the sward indicated a better competitive ability of the aneuploid plants. The presence of aneuploids in the mixed stands did not cause any conspicuous loss of yield. This was displayed by the lack of significant differences in the dry yield per unit area between the two kinds of stands.

Aneuploids in the shrub birch Betula humilis populations in Poland

“…For example, common aneuploid cytotypes confirm substantial involvement of that aberration in the evolution of mosses [15]. It was also shown that in older sward of Festuca pratensis aneuploids had a competitive ability and yielding capacity equal to or the same as euploids [16]. There are four probable explanations for the occurrence of high frequencies of aneuploids in Polish populations of the shrub birch.…”