scholarly journals Biomass Allocation Patterns Are Linked to Genotypic Differences in Whole-Plant Transpiration Efficiency in Sunflower

2017 ◽  
Vol 8 ◽  
Author(s):  
Luciano Velázquez ◽  
Ignacio Alberdi ◽  
Cosme Paz ◽  
Luis Aguirrezábal ◽  
Gustavo Pereyra Irujo
Keyword(s):  
Biomass Allocation ◽  
Genotypic Differences ◽  
Transpiration Efficiency ◽  
Plant Transpiration ◽  
Whole Plant ◽  
Allocation Patterns

Genotypic variation in whole-plant transpiration efficiency in sorghum only partly aligns with variation in stomatal conductance

2019 ◽  
Vol 46 (12) ◽  
pp. 1072 ◽  
Author(s):  
Geetika Geetika ◽  
Erik J. van Oosterom ◽  
Barbara George-Jaeggli ◽  
Miranda Y. Mortlock ◽  
Kurt S. Deifel ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Photosynthetic Capacity ◽  
Genotypic Variation ◽  
Vapour Pressure Deficit ◽  
Genotypic Differences ◽  
Transpiration Efficiency ◽  
Plant Transpiration ◽  
Leaf Chlorophyll ◽  
Residual Variation ◽  
Whole Plant

Water scarcity can limit sorghum (Sorghum bicolor (L.) Moench) production in dryland agriculture, but increased whole-plant transpiration efficiency (TEwp, biomass production per unit of water transpired) can enhance grain yield in such conditions. The objectives of this study were to quantify variation in TEwp for 27 sorghum genotypes and explore the linkages of this variation to responses of the underpinning leaf-level processes to environmental conditions. Individual plants were grown in large lysimeters in two well-watered experiments. Whole-plant transpiration per unit of green leaf area (TGLA) was monitored continuously and stomatal conductance and maximum photosynthetic capacity were measured during sunny conditions on recently expanded leaves. Leaf chlorophyll measurements of the upper five leaves of the main shoot were conducted during early grain filling. TEwp was determined at harvest. The results showed that diurnal patterns in TGLA were determined by vapour pressure deficit (VPD) and by the response of whole-plant conductance to radiation and VPD. Significant genotypic variation in the response of TGLA to VPD occurred and was related to genotypic differences in stomatal conductance. However, variation in TGLA explained only part of the variation in TEwp, with some of the residual variation explained by leaf chlorophyll readings, which were a reflection of photosynthetic capacity. Genotypes with different genetic background often differed in TEwp, TGLA and leaf chlorophyll, indicating potential differences in photosynthetic capacity among these groups. Observed differences in TEwp and its component traits can affect adaptation to drought stress.

scholarly journals Nitrogen addition affects plant biomass allocation but not allometric relationships among different organs across the globe

2020 ◽  
Author(s):  
Kai Yue ◽  
Dario A Fornara ◽  
Wang Li ◽  
Xiangyin Ni ◽  
Yan Peng ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Mass Fraction ◽  
Plant Biomass ◽  
Terrestrial Ecosystems ◽  
Interactive Effects ◽  
N Addition ◽  
Allometric Relationships ◽  
Optimal Partitioning ◽  
Whole Plant ◽  
Allocation Patterns

Abstract Aims Biomass allocation to different organs is a fundamental plant ecophysiological process to better respond to changing environments; yet, it remains poorly understood how patterns of biomass allocation respond to nitrogen (N) additions across terrestrial ecosystems worldwide. Methods We conducted a meta-analysis using 5474 pairwise observations from 333 articles to assess how N addition affected plant biomass and biomass allocation among different organs. We also tested the “ratio-based optimal partitioning” vs. the “isometric allocation” hypotheses to explain potential N addition effects on biomass allocation. Important findings We found that (1) N addition significantly increased whole plant biomass and the biomass of different organs, but decreased root:shoot ratio (RS) and root mass fraction (RMF) while no effects of N addition on leaf mass fraction (LMF) and stem mass fraction (SMF) at the global scale; (2) the effects of N addition on ratio-based biomass allocation were mediated by individual or interactive effects of moderator variables such as experimental conditions, plant functional types, latitudes, and rates of N addition; and (3) N addition did not affect allometric relationships among different organs, suggesting that decreases in RS and RMF may result from isometric allocation patterns following increases in whole plant biomass. Despite alteration of ratio-based biomass allocation between root and shoot by N addition, the unaffected allometric scaling relationships among different organs (including root vs. shoot) suggest that plant biomass allocation patterns are more appropriately explained by the isometric allocation hypothesis rather than the optimal partitioning hypothesis. Our findings contribute to better understand N-induced effects on allometric relationships of terrestrial plants, and suggest that these ecophysiological responses should be incorporated into models that aim to predict how terrestrial ecosystems may respond to enhanced N deposition under future global change scenarios.

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