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Genotypic Variation for Stem Reserves and Mobilization in Wheat: I. Postanthesis Changes in Internode Dry Matter
Author(s) -
Ehdaie B.,
Alloush G. A.,
Madore M. A.,
Waines J. G.
Publication year - 2006
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/cropsci2005.04-0033
Subject(s) - plant stem , dry matter , peduncle (anatomy) , biology , cultivar , dry weight , agronomy , horticulture , mobilization , main stem , botany , archaeology , history
Wheat crops grown in dryland areas may depend more on stem reserves for grain filling than on current photosynthesis. We evaluated the hypothesis that internode length, weight, and specific weight of genotypes affect accumulation and mobilization of stem reserves. This knowledge might complement selection in stressful environments. Genotypic variation for internode characteristics and their effects on dry matter accumulation and mobilization were measured at 10‐d intervals in 11 diverse wheat cultivars grown under well‐watered and droughted field conditions across 2 yr. Relationships among internode characteristics and accumulation and mobilization of stem reserves were determined. The main effect of year, irrigation, genotype, and harvest date and genotype × harvest date interaction were significant. Internode length, weight, and specific weight were reduced under drought. Mobilized dry matter from peduncle, penultimate, and the lower internodes ranged from 43 to 171, 81 to 272, and from 198 to 474 mg, respectively. Mobilized dry matter was less in well‐watered than in droughted conditions for peduncle (93 vs. 110 mg) but not for penultimate (173 vs. 143 mg) and the lower internodes (331 vs. 304 mg). Drought increased mobilization efficiency, expressed as percentage of maximum dry mater mobilized, in the peduncle, penultimate, and the lower internodes by 65, 11, and 5%, respectively. Stem maximum specific weight was correlated ( r = 0.64) with stem mobilized dry matter. Balanced partitioning of stem length into upper and lower internodes and internode maximum specific weight are important in genotypic accumulation and mobilization of stem reserves in wheat.