Red/far-red light mediated stem elongation and anthocyanin accumulation in Stellaria longipes: differential response of alpine and prairie ecotypes

We compared the stem elongation response and anthocyanin accumulation between alpine and prairie plants of Stellaria longipes Goldie under different red/far-red light ratios (R/FR) of 0.7 and 1.9 while all other environmental conditions were uniform. Both ecotypes responded to light quality. The prairie ecotype, considered to be the shade avoider, showed greater stem elongation in response to low R/FR (0.7) than under high R/FR (1.9) as compared with the alpine ecotype. The levels of anthocyanin in prairie plants, as compared with alpine plants, were significantly higher under high R/FR. Under low R/FR, both showed almost the same levels of anthocyanin. Also, the two ecotypes upon etiolation showed differences in the sites of anthocyanin accumulation under different R/FR. The results of the present study show that the extent of the stem elongation response and anthocyanin accumulation in the two ecotypes of S. longipes is likely a result of their origins in two contrasting habitats.