Premium
Import of 14 C‐Photosynthate by Developing Leaves of Sugarcane
Author(s) -
RobinsonBeers Kay,
Sharkey Th. D.,
Evert R. F.
Publication year - 1990
Publication title -
botanica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 0932-8629
DOI - 10.1111/j.1438-8677.1990.tb00184.x
Subject(s) - saccharum , biology , sink (geography) , horticulture , leaf blade , botany , photosynthesis , agronomy , cartography , geography
Sink‐to‐source transition was studied in developing sugarcane ( Saccharum interspecific variety L62–96) leaves. Fully‐expanded, mature sugarcane leaves were fed 14 CO 2 for 20 minutes, incorporating about 617 Bq. After five hours the leaves of each plant were cut into 1‐cm‐length segments that were weighed and then placed in scintillation cocktail for counting. All leaves younger than the leaf fed 14 CO 2 imported labeled photoassimilate. Three to four leaves had both importing and non‐importing regions within the blade and a distinct transition region between them. A transition region was observed in leaves which had expanded to between 30 and 90 % of final blade length. Radioactivity per gram fresh weight was calculated as a measure of sink strength. Sink strength was greatest in the youngest leaf and declined with leaf age. The results of this study indicate that 1) import of photosynthate by developing sugarcane leaves occurs over a longer span of developmental ages than in dicotyledonous leaves and 2) the actual tissue region undergoing transition within such a leaf can be resolved as narrow zone between the importing and non‐importing regions.