Developmental mechanism and distribution pattern of stomatal clusters in Cinnamomum camphora

We report the stomatal cluster development mechanism and distribution pattern in Cinnamomum camphora. The results indicated that the clustered arrangement of meristemoids at the juvenile stage of the leaf development contributed greatly to the pattern of stomatal clusters. Additionally, division of an epidermal cell (EC), which is between small stomata, and growth of small stomata to push the ECs aside to become directly contacting had an impact on the development as well as the pattern of stomatal clusters. The latter way may play a more important role in stomata clustering of the wide-type C. camphora. There are no significant difference in the stomatal index (the number of stomata per the sum of the number of epidermal cells and the number of stomata) among different part of leaves, while the stomatal cluster index (the number of stomata in stomatal clusters per the total number of stomata) was found to increase gradually from the apex to the base and from the middle part to the marginal part of the leaf. The possible reason of this pattern was discussed. Published in Russian in Fiziologiya Rastenii, 2006, Vol. 53, No. 3, pp. 348–353. The text was submitted by the authors in English.