Genetic differentiation in Plantago major: Growth and root respiration and their role in phenotypic adaptation

Abstract

The root respiration and the growth of plants of four inbred lines of Plantago major L. were followed at two levels, of mineral nutrition. In addition the response to a transfer of plants from one condition to the other was studied. The activities of the cytochrome and of the alternative pathway wee determined and used to distinguish between genetic differences among the inbred lines and the plasticity within each inbred line. Root respiration and growth parameters differed significantly between the lines and were directly related to seed number per capsule (low respiratory activity and slow growth – 11 seeds per capsule; high respiratory activity and fast growth – 33 seeds per capsule). Plasticity of respiration and growth parameters is expressed as differences in the total respiration, the activities of the cytochrome and of the alternative pathway, and in the shoot to root ratio, as a response to nutritional level or to changes of the strength of the nutrient solution. Differences in this plasticity in the four selected lines and in quickness of response to a change in mineral nutrition were directly related to the ecological strategy. These results are discussed in relation to the strategy of the genotypes for survival in the field. The high growth rate and the presence of plasticity in line 4 (ssp. Pleiosperma) make this genotype act like an annual, following a ruderal strategy. The lower growth rate and the absence of plasticity in line 1 (ssp. major) fit a more competitive strategy.

Plasticity in life-history traits of Plantago major L. ssp. pleiosperma Pilger

“…The overall pattern of relative importance of the envi ronment in determining differences in life-history character istics, which was found in the present experiments as has been hypothesized, is in accordance with the high amount of phenotypic plasticity in a whole set of physiological char acteristics reported by Kuiper (1982Kuiper ( , 1983 for P. major ssp. pleiosperma grown in culture solution.…”

“…Given the evidence of phenotypic plasticity of P. major ssp. pleiosperma in water culture (Kuiper 1982(Kuiper , 1983 it was hypothesized that differences in growth rate and generative development between the populations of P. major ssp. pleiosperma are determined by environmental factors, rath er than by genetic differentiation.…”

“…This suggests that genetic variation within populations is low. Inbred lines of four populations of P. major were studied by Kuiper (1982Kuiper ( , 1983, who in water-culture experiments demon strated that physiological characteristics, such as ion-stimulated ATP-ase activity and root respiration of plants of P. major ssp. pleiosperma Pilger could be adjusted better than plants of P. major ssp.…”

Effects of Nitrogen Nutrition on Nitrogen Partitioning between Chloroplasts and Mitochondria in Pea and Wheat

“…Thus, there is a close and inverse correlation between nitrogen nutrition and carbohydrate accumulation. In addition, it has been reported by some researchers (2,16,17,26) that under conditions in which excess carbohydrate is produced, the cyanide-resistant respiration is stimulated and may contribute significantly to total respiration. Therefore, it is possible that excess carbohydrate in nitrogen-deficient leaves may have resulted in the relatively high ratio of respiration to photosynthesis.…”

Experimental plant ecology as an approach in coastal population biology

“…Furthermore, given the evidence of phenotypic plasticity for some characteristics of Plantago major ssp. pleiosperma in water culture (Kuiper 1983), Lotz and Blom (1986) tested the hypo thesis that differences in growth rate and genera tive development between the populations of this species are mainly determined by environmental factors. Therefore two experiments have been performed.…”