Abnormal Stomata Research Articles

1) Abnormal stomata, which appeared in the variegated leaves of cytoplasmic male-sterile durum plants were investigated cytologically and classified in six types according to two criteria, namely; degree of differentiation of guard cells and their nuclei, and abnormality or deficiency of subsidiary cells.2) Observation on the cross-section of variegated leaves revealed that the inner air space of the abnormal stomata was smaller than that of normal stomata and that palisade cells in the variegated portion were rather round and arranged irregularly.3) The frequency of occurrence of abnormal stomata was investigated. The percentage of abnormal stomata in the variegated portion reached as high as 38%, but the mean value in the variegated leaf was 12% in longitudinal and 9% in transverse directions. Mature leaves of male-sterile plants do not have abnormal stomata any longer (only 0.2% of the stomata was abnormal).4) Alteration of stomatal distribution was observed in the variegated leaves, that is; the average number of stomata per unit length is decreased in longitudinal direction and is increased in transverse direction, as compared to the number found in normal green leaves.5) It was ascertained from the x2-test that abnormal stomata did not occur at random in the variegated leaf, but occurred serially to a certain degree and that more series were found in longitudinal than in transverse direction.6) Cell length and nuclear length of guard cells in the variegated leaf varied widely and decreased in comparison with those of the normal green leaf. On the other hand, some subsidiary cells were increased in length (although the mean value of cell length was decreased). Width of cell and nucleus did not change to the same degree.7) A correlation between cell length and nuclear length of guard cells was found expressed by a correlation coefficient as high as +0.9137.8) The data presented lead to the assumption that an unknown cytoplasmic factor induces abnormal metabolism in winter leaves, leading to abnormal development of stomata, and on the other hand, to formation of abnormal chloroplasts. The abnormal stomata seem to accelerate the chlorophyll variegation.The present author wishes to express his cordial thanks to Dr. H. G. duBuy, National Institute of Allergy and Infectious Diseases, U.S.A., who was kind enough to read over the manuscript and make some corrections in the style.