Finazzo S F, Davenport T L, Schaffer B
Tropical Research and Education Center, University of Florida, IFAS, 18905 S.W. 280 Street, Homestead, FL 33031, USA.
Tree Physiol. 1994 Feb;14(2):153-64. doi: 10.1093/treephys/14.2.153.
To assess competition for photoassimilates among developing inflorescences, fruitlets and vegetative shoots in avocado (Persea americana Mill.), the distribution of recent photoassimilates was examined before and during flowering, fruit set, and the transition from sink to source of developing vegetative shoots. Mature leaves, located proximal to developing reproductive organs, and developing leaves, located distal to those organs, were exposed to a one-hour pulse of (14)CO(2). Translocation of radiolabeled assimilates was monitored over time and among organs. Overall distribution of assimilates was dependent on dry mass of tissues regardless of organ type. Flowers and fruitlets did not demonstrate greater sink strength than non-autotrophic leaves. Organs receiving assimilates were in phyllotactic alignment with source leaves. Photoassimilates were never limiting, although flower and fruitlet abscission occurred during and long after this competitive period. Carbohydrate availability was sufficient to support the growth of both developing fruitlets and leaves during early stages of reproductive development, and it did not limit fruitlet growth or stimulate fruitlet abscission.
为评估鳄梨（Persea americana Mill.）发育中的花序、小果和营养枝之间对光合产物的竞争情况，在开花期、坐果期以及发育中的营养枝从库向源转变之前和期间，研究了近期光合产物的分布。位于发育中的生殖器官近端的成熟叶以及位于这些器官远端的发育中叶，均接受了1小时的¹⁴CO₂脉冲处理。随着时间推移并在各器官之间监测放射性标记同化物的转运。同化物的总体分布取决于组织的干质量，而与器官类型无关。花和小果并未表现出比非自养叶更强的库强度。接受同化物的器官与源叶呈叶序排列。尽管在这个竞争期内及之后很长时间发生了花和小果脱落，但光合产物从未成为限制因素。在生殖发育早期，碳水化合物的可利用性足以支持发育中的小果和叶片生长，且并未限制小果生长或刺激小果脱落。
