Moss Sporophytes with a Higher Proportion of Leptoids Have Higher Water Transport Rates

The sporophytes of moss plants are dependent on the gametophytes for both photosynthesis and water, which makes conducting cells (hydroids and leptoids) an important part of the sporophyte anatomy. A previous study found that Physcomitrium pyriforme, which has shorter sporophytes, had higher rates of water transport than Funaria hygrometrica, which has taller sporophytes. The aim of this study is to test for differences in the conducting cell anatomy between these two moss species, which could be responsible for differences in water transport rates. We used histology methods to fix, embed, and section sporophyte seta and then quantified the numbers and sizes of the conducting cells. The results revealed that leptoids comprise a higher proportion of the conducting cell area in P. pyriforme, while hydroids comprise more of the conducting cell area in F. hygrometrica. These results point toward the leptoids playing a role in water transport in the moss sporophyte.