Phosphorus deficiency inhibits growth in parallel with photosynthesis in a C3 (Panicum laxum) but not two C4 (P. coloratum and Cenchrus ciliaris) grasses

2007 ◽  
Vol 34 (1) ◽  
pp. 72 ◽  
Author(s):  
Oula Ghannoum ◽  
Jann P. Conroy

This study compared the growth and photosynthetic responses of one C3 (Panicum laxum L.) and two C4 grasses (Panicum coloratum L. and Cenchrus ciliaris L.) to changes in soil phosphorus (P) nutrition. Plants were grown in potted soil amended with six different concentrations of P. One week before harvest, leaf elongation and photosynthetic rates and the contents of carbohydrate, P and inorganic phosphate (Pi) were measured. Five weeks after germination, plants were harvested to estimate biomass accumulation. At each soil P supply, leaf P contents were lower in the C3 (0.6–2.6 mmol P m–2) than in the two C4 grasses (0.8–4.1 mmol P m–2), and Pi constituted ~40–65% of total leaf P. The P deficiency reduced leaf growth, tillering and plant dry mass to a similar extent in all three grasses. In contrast, P deficiency suppressed photosynthetic rates to a greater extent in the C3 (50%) than the C4 grasses (25%). The foliar contents of non-structural carbohydrates were affected only slightly by soil P supply in all three species. Leaf mass per area decreased at low P in the two C4 grasses only, and biomass partitioning changed little with soil P supply. The percentage changes in assimilation rates and plant dry mass were linearly related in the C3 but not the C4 plants. Thus, P deficiency reduced growth in parallel with reductions of photosynthesis in the C3 grass, and independently of photosynthesis in the two C4 grasses. We propose that this may be related to a greater Pi requirement of C4 relative to C3 photosynthesis. Photosynthetic P use efficiency was greater and increased more with P deficiency in the C4 relative to the C3 species. The opposite was observed for whole-plant P-use efficiency. Hence, the greater P-use efficiency of C4 photosynthesis was not transferred to the whole-plant level, mainly as a result of the larger and constant leaf P fraction in the two C4 grasses.

2011 ◽  
Vol 62 (6) ◽  
pp. 467 ◽  
Author(s):  
Qifu Ma ◽  
Zed Rengel ◽  
Kadambot H. M. Siddique

Heterogeneity of soil nutrients, particularly phosphorus (P), is widespread in modern agriculture due to increased adoption of no-till farming, but P-use efficiency and related physiological processes in plants grown in soils with variable distribution of nutrients are not well documented. In a glasshouse column experiment, wheat (Triticum aestivum L.) and white lupin (Lupinus albus L.) were subjected to 50 mg P/kg at 7–10 cm depth (hotspot P) or 5 mg P/kg in the whole profile (uniform P), with both treatments receiving the same amount of P. Measurements were made of plant growth, gas exchange, P uptake, and root distribution. Plants with hotspot P supply had more biomass and P content than those with uniform P supply. The ratios of hotspot to uniform P supply for shoot parameters, but not for root parameters, were lower in L. albus than wheat, indicating that L. albus was better able than wheat to acquire and utilise P from low-P soil. Cluster roots in L. albus were enhanced by low shoot P concentration but suppressed by high shoot P concentration. Soil P supply decreased root thickness and the root-to-shoot ratio in wheat but had little effect on L. albus. The formation of cluster roots in low-P soil and greater proliferation and surface area of roots in the localised, P-enriched zone in L. albus than in wheat would increase plant P use in heterogeneous soils. L. albus also used proportionally less assimilated carbon than wheat for root growth in response to soil P deficiency. The comparative advantage of each strategy by wheat and L. albus for P-use efficiency under heterogeneous P supply may depend on the levels of P in the enriched v. low-P portions of the root-zone and other soil constraints such as water, nitrogen, or potassium supply.


Author(s):  
N. Boukhalfa-Deraoui ◽  
L. Hanifi-Mekliche ◽  
A. Mekliche

Background: P deficiency is very common in alkaline - calcareous soil. Therefore, application of foliar-absorbed fertilizers may be an effective strategy to overcome the low bioavailability of phosphorus in soil, by improving phosphorus use efficiency and reduced nutrients loses.Methods: A field experiment was carried out in 2006-07 growing season at El-Menia (southeastern Algeria) to evaluated the effect of two foliar P (agriphos and leader-start) and three soil P (TSP P 46, Fosfactyl NP 3:22 and NPKs 8:36:13,5+15) on yield and P use efficiency of durum wheat crop Triticum durum Desf. var. Carioca and on available P and total P in soil.Result: Data showed that significant effect of soil P fertilizer on grain yield components (ears m-², grains ear-1 and the 1000 grains weight), grain P use efficiency and available P in soil. The best values were recorded by NPKs fertilizer, but no differences were observed for these parameters among foliar fertilizer sources.


2010 ◽  
Vol 28 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jonathan D. Sammons ◽  
Daniel K. Struve

Abstract Fertilization and irrigation practices affect water-and nutrient use-efficiencies in container-produced nursery crops. This study was conducted to determine if gravimetric monitoring of a plant-substrate-container unit could manage real-time irrigation volume to achieve a near zero leachate fraction and to study baldcypress (Taxodium distichum (L.) Rich.) growth, nutrient accumulation and water-use efficiency under a factorial combination of two irrigation leachate fractions and two controlled release fertilizer (CFR) rates. Baldcypress plants were grown at either 45 or 90 g of 15N–3.1P-12.5K (15-7-15 Multicote, six-month controlled release fertilizer top dressed on each container), and two irrigation rates, near-zero or 0.2 leachate fraction. Height growth, whole plant dry mass and shoot: root dry mass ratios, and water-use efficiency were not affected by a fertilizer and irrigation interaction. The higher fertilizer rate increased the whole plant N and K concentrations. Relative to a 20% leachate fraction irrigation regime, a near-zero leachate fraction decreased leachate volume and root, shoot and whole plant dry mass, while leachate electrical conductivity (EC), plant tissue mineral nutrient concentrations and water use efficiency increased. Although baldcypress whole plant dry mass was reduced under the near-zero leachate irrigation regime (presumably due to high soluble salt levels) there was no difference in height and stem diameter at the higher fertilizer rate between the two irrigation regimes. The near-zero leachate irrigation regime applied approximately one-half the irrigation volume of the 0.2 LF irrigation regime.


2013 ◽  
Vol 64 (9) ◽  
pp. 881 ◽  
Author(s):  
Chaoyuan Zheng ◽  
Junling Zhang ◽  
Xiaolin Li

Arbuscular mycorrhizal (AM) fungi are known to facilitate effective acquisition of phosphorus (P) by host plants in low P soils. However, the contribution of mycorrhizal traits to high P-use efficiency in modern-bred maize genotypes is still not clear. In the present study one backcross maize inbred line 224 (bred for high P-use efficiency) was used as the host plant associated with AM fungal species (Rhizophagus irregularis or Glomus mosseae) grown at a range of soil P treatments (10, 20, 30, 40, 50, 100 mg P kg–1, Experiment 1) or foliar P applications (0, 0.025%, 0.5% m/v, Experiment 2). The experiments were to test the hypothesis whether the change point of the mycorrhizal growth and P responsiveness of 224, as well as the expression of ZEAma;Pht1;6 was at or near the optimal P supply level. In addition, different AM inoculants might differ in regulating P uptake of the host. Our results indicated that inbred line 224 was highly responsive to mycorrhizal inoculation. In Experiment 1, root colonisation rate, hyphal length density and alkaline phosphatase increased with the increase of soil P supply level. However, the mycorrhizal growth response (MGR) and P accumulation in shoot (MPR) were greatly affected by soil P supply level and varied between the two fungal species. Maize plants exhibited higher MGR and MPR at lower P supply when inoculated with R. irregularis, and at intermediate P supply when inoculated with G. mosseae. In Experiment 2, shoot P uptake was significantly increased by foliar P supply and inoculation, whereas shoot growth was significantly affected by P supply and the interaction. The expression of the AM-inducible Pi transporter gene ZEAma;Pht1;6 was neither significantly affected by soil (except at 100 mg P kg–1, Experiment 1) or foliar P supply level, nor by fungal species. Root P uptake efficiency (RPUE) was generally greatly increased by mycorrhizal colonisation at all P supply levels in both experiments, and significant correlations were observed between mycorrhizal variables and RPUE in Experiment 1. Our results indicate that the formation of mycorrhizal association could increase RPUE and thus may be partly attributed to high P-use efficiency of inbred line 224. The different responsiveness of mycorrhizal fungi to soil-available P implies the importance for the development of precision strategies to optimise the potential function of AM fungi under different P fertilisation management regime in agricultural soils.


2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.


AoB Plants ◽  
2019 ◽  
Author(s):  
M A Míguez-Montero ◽  
A Valentine ◽  
M A Pérez-Fernández

Abstract The impact of phosphorus (P) nutrition on plant growth, symbiotic N2 fixation, and phosphorus and nitrogen use and their assimilation was investigated in four leguminous plants of the genus Cytisus. Plants inoculated with Rhizobium strains isolated from plants of the four species growing in the wild were crop under controlled conditions in soils with either low P (5 µM) or high P (500 µM). The experiment was replicated in the presence and absence of plant irrigation to test for the effects of drought stress of inoculated and non-inoculated plants under the two P levels of fertilization. P-low treatments increased nodule production while plant biomass and shoot and root P and N contents were maximum at sufficient P. The reduction of P in the soil clearly induced biological nitrogen fixation and greater phosphorus and nitrogen uptake efficiencies, as shown by the total N and P accumulated in plants. Similarly, distinct tolerances to drought support this idea. Cytisus balansae had the lowest tolerance to water scarcity. Cytisus multiflorus and Cytisus scoparius were the most resistant species to drought, with this resistance enhanced in the inoculated plants. In the four species, the inoculation treatment clearly enhanced N-use efficiency, whereas P-use efficiency was greater in the non-inoculated plants in the irrigated treatment. With a P-induced demand for N, the plants nodulated prolifically and increased N supply from biological fixation. The physiological basis for N2-fixing C. scoparius and C. striatus maintaining growth at low P supply and responding to greater P supply is through balanced acquisition of P and N for plant demand. Native shrubby legumes are key species in natural ecosystems due to their capability to increase the net N budget in plants and soils and because they modulate the phosphorus availability. Four legumes in the genus Cytisus either native to or commonly represented in the Iberian Peninsula proved to be able shift their N use depending on the soil P availability and on the interactions established with their Bradyrhizobium symbionts. In the four species the inoculation treatment clearly enhanced N-use efficiency and drought tolerance, whereas P-use efficiency was greater in the non-inoculated plants in the irrigated treatment.


Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 191 ◽  
Author(s):  
Patricia Poblete-Grant ◽  
Philippe Biron ◽  
Thierry Bariac ◽  
Paula Cartes ◽  
María de La Luz Mora ◽  
...  

To maintain grassland productivity and limit resource depletion, scarce mineral P (phosphorus) fertilizers must be replaced by alternative P sources. The effect of these amendments on plant growth may depend on physicochemical soil parameters, in particular pH. The objective of this study was to investigate the effect of soil pH on biomass production, P use efficiency, and soil P forms after P amendment application (100 mg kg−1 P) using poultry manure compost (PM), rock phosphate (RP), and their combination (PMRP). We performed a growth chamber experiment with ryegrass plants (Lolium perenne) grown on two soil types with contrasting pH under controlled conditions for 7 weeks. Chemical P fractions, biomass production, and P concentrations were measured to calculate plant uptake and P use efficiency. We found a strong synergistic effect on the available soil P, while antagonistic effects were observed for ryegrass production and P uptake. We conclude that although the combination of PM and RP has positive effects in terms of soil P availability, the combined effects of the mixture must be taken into account and further evaluated for different soil types and grassland plants to maximize synergistic effects and to minimize antagonistic ones.


2020 ◽  
Vol 80 (04) ◽  
Author(s):  
Harsh Kumar Dikshit ◽  
Venkata Ravi Prakash Reddy ◽  
Gyan Prakash Mishra ◽  
Muraleedhar Aski ◽  
Renu Pandey ◽  
...  

Phosphorus (P) deficiency is one of the serious problems affecting plant growth in mungbean in different parts of the world. The root, shoot and biomass related traits were investigated for identifying P-efficient genotypes in 54 mungbean genotypes under low-P (LP) and normal-P (NP) conditions. In this study, the membership function value of P use efficiency of studied traits was used as a compendious index for studying P use efficiency (PUE) in mungbean. Among the studied traits, mean values of total root volume, chlorophyll concentration, root dry weight (RDW) and root to shoot ratio increased >25% under LP condition indicating that these traits are highly responsive to P deficiency. Correlation and stepwise regression analysis revealed that RDW explained most of the variation and could be used as a clear indicator of PUE. The five highly P-efficient genotypes namely, MH 805, M 42, PUSA 9531, EC 398885 and M 209 with high MFVP values may be used for PUE improvement in mungbean.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12156
Author(s):  
Venkata Ravi Prakash Reddy ◽  
Harsh Kumar Dikshit ◽  
Gyan Prakash Mishra ◽  
Muraleedhar Aski ◽  
Akanksha Singh ◽  
...  

Phosphorus (P) is one of the major constraints for crop growth and development, owing to low availability and least mobility in many tropical soil conditions. Categorization of existing germplasm under P deficient conditions is a prerequisite for the selection and development of P efficient genotypes in the mungbean. In the present investigation, 36 diverse genotypes were categorized for phosphorus use efficiency traits using four different techniques for identification of phosphorus use efficient mungbean genotypes. The studied genotypes were categorized for P efficiency based on efficiency, responsiveness, and stress tolerance score of genotypes under normal and low P conditions. The mean values of traits, root dry mass, root to shoot ratio, and P utilization efficiency are significantly higher under low P conditions indicating the high responsiveness of traits to P deficiency. The presence of significant interaction between genotypes and P treatment indicates the evaluated genotypes were significantly affected by P treatment for studied traits. The total P uptake showed significant and positive correlations with root dry mass, shoot dry mass, total dry mass,and P concentration under both P regimes. Out of the four techniques used for the categorization of genotypes for P efficiency, three techniques revealed that the genotype PUSA 1333, followed by Pusa Vishal, PUSA 1031, and Pusa Ratna is efficient. The categorization based on stress tolerance score is the finest way to study variation and for the selection of contrasting genotypes for P efficiency. The identified P efficient genotypes would be valuable resources for genetic enhancement of P use efficiency in mungbean breeding.


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