Table 1.

Effects of gravity on the growth of and chloroplast numbers in P. patens leaf cells

Traits	1×g	10×g	P value
Gametophore features
Shoot length (mm)	14.9 ± 2.4	12.1 ± 2.2	***
Rhizoid length (mm)	7.8 ± 1.7	14.6 ± 4.2	***
Shoot dry mass (mg)	0.343 ± 0.056	0.272 ± 0.039	*
Rhizoid dry mass (mg)	0.0240 ± 0.0082	0.0608 ± 0.0172	**
Canopy features
Shoot dry mass (mg)	32.4 ± 4.7	48.1 ± 7.7	**
Rhizoid dry mass (mg)	2.30 ± 0.73	9.91 ± 3.34	**
Numbers of plants	92.2 ± 4.5	170.7 ± 10.0	***
Numbers of chloroplasts per leaf cell	24.6 ± 4.5	24.5 ± 4.4	n.s.

The length and dry mass of the shoot (leaf + stem) and rhizoid of each gametophore (n = 75–76), and the dry mass of shoots and rhizoids in the canopy and numbers of gametophores for each canopy (n = 6–7) are shown. The numbers of chloroplasts per each cell were measured for fresh leaves using digitized images (n = 54–56). Average ± SD values are shown for all traits. Differences between averaged values were analyzed using Welch’s t-test, with significant levels of * P < 0.05, ** P < 0.01, and *** P < 0.001 for the effects of gravity. n.s. means no significant difference