Phosphate responses of some Trifolium repens×T. uniflorum interspecific hybrids grown in soil

2014 ◽  
Vol 65 (4) ◽  
pp. 382 ◽  
Author(s):  
S. N. Nichols ◽  
J. R. Crush ◽  
L. Ouyang
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Interspecific Hybrids ◽  
Root Surface ◽  
P Uptake ◽  
Sand Culture ◽  
Interspecific Hybridisation ◽  
Growth Responses ◽  
Root Tips ◽  
Soil P

Previous studies in sand culture suggested that some white clover (Trifolium repens) × T. uniflorum interspecific hybrids were more tolerant than white clover of low external phosphate (P) supply. Here, P acquisition and growth responses were determined in soil for two T. repens × T. uniflorum backcross hybrids and their parental white clover cultivar, grown in a glasshouse pot experiment at Olsen P of 6, 7, 9, 14, or 20 mg P kg–1 soil. Growth of all of the clover entries responded strongly to increasing soil P levels, and one hybrid clover grew, on average, 17% better than the white clover control cultivar at Olsen soil P 9–20 mg kg–1. Internal P concentrations and shoot growth per unit P absorbed did not differ among the clovers. Instead, improved growth of the hybrid resulted from a greater ability to acquire soil P. This hybrid had the longest, most frequently branched roots. Frequent branching and growth of root tips into fresh soil would reduce the limitations to P uptake imposed by slow diffusion of P to the root surface. The results confirm previous observations that interspecific hybridisation is a useful strategy for increasing the range of P responsiveness in breeding populations for white clover.

Nutrient responses and macronutrient composition of some Trifolium repens×Trifolium uniflorum interspecific hybrids

2014 ◽  
Vol 65 (4) ◽  
pp. 370 ◽  
Author(s):  
S. N. Nichols ◽  
R. W. Hofmann ◽  
W. M. Williams ◽  
J. R. Crush
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Dry Weight ◽  
Transgressive Segregation ◽  
Sand Culture ◽  
Interspecific Hybridisation ◽  
Root Characteristics ◽  
Macronutrient Composition ◽  
Soil P ◽  
Matter Production

Interspecific hybridisation is being utilised in white clover (Trifolium repens L.) breeding programs to overcome factors currently restricting productivity and persistence. Valuable new traits that may be introduced from the wild relative T. uniflorum include root characteristics and other adaptations to its natural, Mediterranean habitat. This study examined the effect of hybridisation on growth and macronutrient composition of white clover compared with T. uniflorum and T. repens × T. uniflorum backcross 1 (BC1) hybrids in two glasshouse sand culture experiments. Shoot and root dry weights of BC1 hybrids were greater than of white clover in low-concentration nutrient treatments but not in a more concentrated treatment. Decreases in dry weight with decreasing nutrient treatment strength were also smaller for some BC1 hybrids compared with white clover and other hybrid families. Most foliar macronutrient levels were adequate for white clover growth, but mean shoot or leaf phosphorus (P) concentrations were below published critical levels. Higher dry matter production under these low internal P concentrations suggests that some T. repens × T. uniflorum BC1 hybrids may be more tolerant of lower soil P levels than white clover. Such adaptations are likely to have been inherited from T. uniflorum. However, transgressive segregation may also be occurring, as T. uniflorum was larger than white clover in some, but not all, cases of low nutrient supply.

Phosphate response of Trifolium uniflorum compared with T. repens and some T. repens×T. uniflorum hybrids

2015 ◽  
Vol 66 (8) ◽  
pp. 857 ◽  
Author(s):  
S. N. Nichols ◽  
J. R. Crush
Keyword(s):  
Growth Rate ◽  
White Clover ◽  
Leaf Tissue ◽  
High Growth ◽  
High Growth Rate ◽  
Interspecific Hybridisation ◽  
Growth Responses ◽  
Slow Growth Rate ◽  
Soil P ◽  
Hill Country

Introgression of genes from Trifolium uniflorum L. into T. repens L. (white clover) is being investigated as a method to improve phosphorus (P) use efficiency in white clover; however, little is known about the edaphic adaptations or P physiology of T. uniflorum. Growth responses to added P of T. uniflorum, T. repens and some T. repens × T. uniflorum hybrids were determined in a glasshouse experiment in pots of soil. Trifolium uniflorum showed traits consistent with adaptation to low-P soils: slow growth rate, small leaves, relatively high leaf-tissue P concentrations, and sequestration of P in its roots when soil P levels were increased. The response of Kopu II, one of the hybrid backcross parents, was quite different; it showed high growth rate, large leaves, much lower leaf P concentrations, and a large decrease in root : shoot P allocation as soil P increased. Tahora, the other backcross parent, exhibited several characteristics that were intermediate between Kopu II and T. uniflorum, probably reflecting its breeding origins from New Zealand hill-country ecotypes. This study confirms the potential for interspecific hybridisation with T. uniflorum to increase the tolerance of white clover to low soil P levels, through incorporation of traits related to edaphic adaptations. Variation among the hybrid families in their response to changing soil P confirmed previously published conclusions about the need to screen widely in hybrid material.

Uptake of phosphorus from different sources by Lotus Pedunculatus and three genotypes of Trifolium Repens .1. Plant yield and phosphate efficiency

Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 1015 ◽  
Author(s):  
SN Trolove ◽  
MJ Hedley ◽  
JR Caradus ◽  
AD Mackay
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Unit Length ◽  
P Uptake ◽  
Selection Line ◽  
P Efficiency ◽  
Soil P ◽  
Lotus Pedunculatus ◽  
Unit Plant ◽  
Different Sources

The breeding of phosphate (P) efficient pastoral legumes could reduce the amount of fertiliser required on pastoral farms. In this study, Lotus pedunculatus and 3 genotypes of white clover (Trifolium repens L.) known to differ in their ability to respond to added P were grown on unfertilised soil and soil to which either monocalcium phosphate (MCP) or North Carolina phosphate rock (NCPR) were added. White clover genotype 8D (a selection line from Crau) had a greater (P < 0.05) internal P efficiency (shoot DM production per unit plant P) than 1A (a selection line from Gwenda) or lotus on unfertilised soil, whereas on fertilised soil, lotus had a significantly higher (P < 0.05) internal P efficiency than 2 of the white clover genotypes on MCP-fertilised soil (P < 0.01) and all 3 white clover genotypes on NCPR-fertlised soil (P < 0.01). Lotus also had a higher (P < 0.01) external P efficiency (total P uptake) than all 3 white clover genotypes on the 2 fertilised treatments. This was due to a greater root length, not a greater P uptake per unit length.

Impact of insect root herbivory on the growth and nitrogen and carbon contents of white clover (Trifolium repens) seedlings

1996 ◽  
Vol 74 (10) ◽  
pp. 1591-1595 ◽  
Author(s):  
P. J. Murray ◽  
D. J. Hatch ◽  
J. B. Cliquet
Keyword(s):  
Root Exudates ◽  
White Clover ◽  
Trifolium Repens ◽  
Sequential Sampling ◽  
Sand Culture ◽  
N Fixation ◽  
Total N ◽  
Nitrogenous Compounds ◽  
Root Herbivory ◽  
The Impact

The impact of root herbivory by larvae of the weevil Sitona flavescens (Marsh.) on the growth and carbon and nitrogen economies of seedlings of white clover (Trifolium repens L.) and the nature and extent of nitrogenous compounds found in the root exudates taken from the rhizosphere were investigated. The seedlings were grown in sand culture in a system of microlysimeters that enabled sequential sampling of root exudates. Weevil infestation significantly reduced foliar biomass and total N and C contents and impaired N-fixation. The C:N ratios of the infested plants were significantly increased compared with those of uninfested seedlings. The most abundant amino acids in the exudates were aspartic acid and serine. Keywords: nitrogen fixation, Sitona spp., root exudates, white clover.

Growth and chemical composition of white clover as affected by sulphur supply

1959 ◽  
Vol 10 (4) ◽  
pp. 500 ◽  
Author(s):  
K Spencer
Keyword(s):  
Chemical Composition ◽  
Total Nitrogen ◽  
White Clover ◽  
Trifolium Repens ◽  
Sand Culture ◽  
Protein Nitrogen ◽  
Whole Plant ◽  
Sulphate Sulphur ◽  
Trifolium Repens L ◽  
Four Levels

Plants of white clover (Trifolium repens L. var. Ladino) were grown in sand culture with four levels of sulphur supply. Growth increased with increasing sulphur supply, all plants except those at the highest sulphur level showing deficiency symptoms. As the severity of the deficiency increased, the root system formed a proportionately larger part of the plant, and the stems and petioles smaller proportions; the proportion of the whole plant formed by the laminae was reduced to only a slight extent. Nitrogen and sulphur fractions were examined in the laminae, nitrogen at each of three harvests and sulphur at the second harvest. The percentages of protein nitrogen and of total nitrogen increased as sulphur supply increased, protein nitrogen forming a greater proportion of the total nitrogen at the higher sulphur levels. In contrast, protein sulphur formed the bulk of the total sulphur in deficient plants, but as sulphur supply approached an adequate level for growth, there was a marked increase in non-protein organic sulphur and a smaller increase in sulphate sulphur. In this respect, white clover appears to differ from legumes other than Trifolium spp. and from non-legumes, all of which accumulate sulphur mainly as sulphate.

Seed production trait associations and inheritance in interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum

2017 ◽  
Vol 68 (9) ◽  
pp. 885
Author(s):  
Muhammad Naeem ◽  
I. M. Verry ◽  
P. D. Kemp ◽  
J. P. Millner ◽  
W. M. Williams
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Root Traits ◽  
Interspecific Hybridisation ◽  
Production Traits ◽  
Root Characteristics ◽  
Vegetative Traits ◽  
Almost All ◽  
Trait Associations

Trifolium repens L. (white clover) is an important component of temperate pastures, but its root morphology makes it vulnerable to drought and pest attack. T. uniflorum is a wild species, adapted to dry environments, with deep woody roots but poor vegetative growth and only 1–3 florets per inflorescence (head). Interspecific hybridisation to incorporate the drought tolerance and root characteristics of T. uniflorum into white clover led to primary hybrids (F1 and BC1) with poor seed production. Advanced-generation hybrids expressed high variation for almost all seed-production traits, and seed production responded to selection. To inform future breeding programs, trait associations and heritabilities were analysed. Numbers of heads per plant, florets per head and seeds per floret were important factors with moderate–high heritabilities. The derived traits, numbers of seeds per head, florets per plant and seeds per plant, expressed low–moderate heritabilities. No negative associations between seed production and root traits were found in the hybrids, nor were there any negative associations among head production, persistence and foliage production. Selection for improved seed-production traits should be effective without adversely affecting vegetative traits.

Growth Responses of White Clover, Trifolium repens L., Progenies from Five Diverse Geographic Locations 1

Crop Science ◽  
1964 ◽  
Vol 4 (3) ◽  
pp. 295-297 ◽  
Author(s):  
R. J. Bula ◽  
R. G. May ◽  
C. S. Garrison ◽  
C. M. Rincker ◽  
D. R. McAllister
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Growth Responses ◽  
Geographic Locations ◽  
Trifolium Repens L

Drought resistance of Trifolium repens×Trifolium uniflorum interspecific hybrids

2014 ◽  
Vol 65 (9) ◽  
pp. 911 ◽  
Author(s):  
S. N. Nichols ◽  
R. W. Hofmann ◽  
W. M. Williams
Keyword(s):  
Water Stress ◽  
Drought Resistance ◽  
White Clover ◽  
Trifolium Repens ◽  
Dry Weight ◽  
Root Diameter ◽  
Internode Length ◽  
Lateral Spread ◽  
Interspecific Hybridisation ◽  
Leaf Lamina

White clover (Trifolium repens L.) is a widely used and highly valued temperate legume; however, its productivity and survival are restricted under dryland and drought conditions. This study investigated whether drought resistance of white clover could be improved by interspecific hybridisation with Trifolium uniflorum L. After almost 4 months without irrigation in a rain-shelter facility, shoot dry weight (DW) decreased significantly less in first-generation backcross (BC1) hybrids (–47%) than second-generation backcross (BC2) hybrids (–68%) and white clover (–69%). Stolon morphological parameters such as internode length and leaf lamina area also decreased less under water stress in the BC1 hybrids than in BC2 and white clover. There was also lower senescence in BC1 under water stress than in the other clover types. Genotypes with smaller changes in leaf lamina area, internode length, senescence and lateral spread had smaller changes in shoot DW, and there were significant correlations between constitutive levels of some characteristics and the effect of water stress on shoot DW. Under water stress, the growth form of the BC1 hybrids was compact, dense and prostrate, whereas white clover was more spreading and open. Increased allocation of dry matter to roots under drought, and greater root diameter, may also have influenced the ability of BC1 hybrids to maintain water uptake and key physiological processes. Overall, the data confirm that the drought resistance of white clover can be improved through hybridisation with T. uniflorum.

scholarly journals Enhanced Adaptation to Low-P stress by Altering Rhizosphere Exudation and P-Uptake Rate other than Root Morphological Traits in Two Maize Genotypes

2019 ◽  
Author(s):  
Hongliang Tang ◽  
Yazhou Wang ◽  
Le Niu ◽  
Wei Jing ◽  
Yinglong Chen
Keyword(s):  
Uptake Rate ◽  
Root Hair ◽  
Root Length ◽  
Root Surface ◽  
P Uptake ◽  
Physiological Traits ◽  
Root Surface Area ◽  
Rhizosphere Ph ◽  
Soil P ◽  
Maize Cultivars

Alterations in root morphology and physiology are important strategies in plants to adapt to low-phosphorus (P) environments. Maize genotypes differed in nitrogen (N) efficiency may also respond differently to low P stress. This study aimed to investigate the responses of root morphological and physiological traits of these two maize cultivars to P deficit and how these traits were linked with the acquisition of soil P. Two maize cultivars, XY335 (N efficient) and ZD958 (N inefficient), were cultivated for 40 days in a calcareous loamy soil amended with (high P) or without (low P) P. Functional root traits were used to evaluate the morphological and physiological responses to low P supply. Two separate short-term experiments determined the correlation between P uptake rate and P supply intensity (hydroponic) or root hair length under two P treatments (rhizobox). Low P status significantly simulated biomass allocation to roots, specific root length and exudations of carboxylates, while decreased root diameter and rhizosphere pH in both maize cultivars. Two cultivars had different total root length and root surface area under low P stress: increased in ZD958 and decreased in XY335. Both genotypes developed longer root hair under P deficit. ZD958 (greater biomass and shoot P content) has a greater capability at accessing soil P than XY335. Rhizosphere exudation of citric acid was significantly higher in ZD958 than in XY335, while there was not significant genotypic difference in rhizosphere pH and exudation of malic acid and acid phosphatase activity. ZD958 had higher P uptake rate than XY335 when solution P was between 12.5 and 250 &micro;M. This study identified ZD958 as a P-efficient genotype, which better adapted to low P stress by altering root physiological traits (exudation of citric acid and P uptake rate), rather than root morphological traits (total root length, root surface area, root hair length). Our results highlight the importance of analyzing root morphological and physiological traits to enhance our understanding of the physiological mechanisms of P acquisition.

scholarly journals Reducing Phenanthrene Contamination in Trifolium repens L. With Root-Associated Phenanthrene-Degrading Bacterium Diaphorobacter sp. Phe15

2021 ◽  
Vol 12 ◽  
Author(s):  
Hui Zhao ◽  
Yujun Gu ◽  
Xiangyu Liu ◽  
Juan Liu ◽  
Michael Gatheru Waigi
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Root Surface ◽  
Seed Soaking ◽  
Degrading Bacterium ◽  
Free Treatment ◽  
Polycyclic Aromatic ◽  
Clover Root ◽  
And Performance ◽  
Root Surfaces

Some root-associated bacteria could degrade polycyclic aromatic hydrocarbons (PAHs) in contaminated soil; however, their dynamic distribution and performance on root surface and in inner plant tissues are still unclear. In this study, greenhouse container experiments were conducted by inoculating the phenanthrene-degrading bacterium Diaphorobacter sp. Phe15, which was isolated from root surfaces of healthy plants contaminated with PAHs, with the white clover (Trifolium repens L.) via root irrigation or seed soaking. The dynamic colonization, distribution, and performance of Phe15 in white clover were investigated. Strain Phe15 could efficiently degrade phenanthrene in shaking flasks and produce IAA and siderophore. After cultivation for 30, 40, and 50 days, it could colonize the root surface of white clover by forming aggregates and enter its inner tissues via root irrigation or seed soaking. The number of strain Phe15 colonized on the white clover root surfaces was the highest, reaching 6.03 Log CFU⋅g–1 FW, followed by that in the roots and the least in the shoots. Colonization of Phe15 significantly reduced the contents of phenanthrene in white clover; the contents of phenanthrene in Phe15-inoculated plants roots and shoots were reduced by 29.92–43.16 and 41.36–51.29%, respectively, compared with the Phe15-free treatment. The Phe15 colonization also significantly enhanced the phenanthrene removal from rhizosphere soil. The colonization and performance of strain Phe15 in white clove inoculated via root inoculation were better than seed soaking. This study provides the technical support and the resource of strains for reducing the plant PAH pollution in PAH-contaminated areas.

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