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Partitioning of 14 C‐Photosynthate and Biomass in Relation to Senescene Characteristics of Sorghum
Author(s) -
Victor D. M.,
Cralle H. T.,
Miller F. R.
Publication year - 1989
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1989.0011183x002900040046x
Subject(s) - plant stem , hybrid , sorghum , biology , starch , biomass (ecology) , agronomy , main stem , botany , biomass partitioning , horticulture , biochemistry
The stems remaining after harvest of sorghum [ Sorghum bicolor (L.) Moench] grain are a low‐cost source of biomass. Semidwarf hybrids exhibiting nonsenescent characteristics may yield more stem biomass than senescent hybrids. This study compared a nonsenescent to a senescent hybrid of semidwarf sorghum using dry wt. and partitioning of 14 C‐photosynthate and 14 C‐starch at three stages. A leaf was exposed to 14 CO 2 or 14 C‐starch was injected into the middle internode of each hybriduring grain filling and at or after (post) black layer of the grain. Although dry wt. of stem internodes were significantly ( P ≤ 0.05) greater for the nonsenescent compared the senescent hybrid, 14 C‐photosynthate partitioning among parts did not differ between hybrids after chase periods of 5 or 7 d. Patterns of 14 C‐photosynthate partitioning indicated grain, stem internodes, and lateral branches were dominant sinks at grain filling, black layer, and post black layer, respectively. Lateral branch growth comprised all of the biomass increase from black layer to post black layer. At post black layer, 47% of assimilated 14 CO 2 was partitioned to lateral branches. Both 14 C‐photosynthate and 14 C‐starch were remobilized from stem internodes to lateral branches of both hybrids after black layer. Although unmeasured in previous comparisons betweenonsenescent and senescent sorghum hybrids, lateral branch growth limited storage of 14 C‐photosynthate in stem internodes and resulted in similar patterns of 14 C‐photosynthate partitioning for the two hybrids after black layer in this study.