ANATOMICAL STUDIES OF THE LEAF YELLOWING PROCESS ON LILIUM ‘POLLYANNA’ FOLLOWING SOME PLANT GROWTH REGULATORS APPLICATION

Leaf yellowing process was investigated anatomically using applications of GA₃, GA₃+BA, ethephon, and STS pulse-treatment.
Seven days after application, leaf yellowing was found in ethephon and STS pulse-treatments.
In ethephon application, cell walls of the palisade and spongy tissue absorbed less stain with toluidine blue-O. The results indicate that cell wall components, such as pectin and cellulose, degrade rapidly.
Chloroplast and starch grain in the palisade and spongy tissue disappeared.
In contrast, with GA₃ and GA₃+BA treatments, leaves showed dark green until seven days.
In these treatments, number of chloroplast and starch grain in the palisade and spongy tissue cells increased.
The palisade and spongy tissue cells in leaves may act as a sink for compounds such as sucrose and amino acids to prevent leaf yellowing.

IX International Symposium on Flower Bulbs

T. Tabuchi, A. Uesugi, A. Furukawa, M. Moriyama, K. Toba

anatomy, leaf yellowing, Lilium, palisade tissue, plant growth regulators, spongy tissue

https://doi.org/10.17660/ActaHortic.2005.673.100