Root and Shoot Growth Responses to Salinity in Maize and Soybean

1995 ◽  
Vol 87 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Joseph Shalhevet ◽  
Morris G. Huck ◽  
Bryan P. Schroeder
1990 ◽  
Vol 115 (2) ◽  
pp. 196-202 ◽  
Author(s):  
Michael A. Arnold ◽  
Eric Young

Malus dometica Borkh., M. anis, M. prunifolia Borkh., M. × robusta Rehd., M. antonovka, M. borwinkw, and M. ranetka bare-root seedlings were chilled at 5C for 0, 400, 800, 1200, or 1600 hours. After chilling treatments, one-half of the seedlings were root-pruned and all seedlings were placed in a greenhouse for 15 days. Quantitative differences between species in the timing and magnitude of new root and shoot growth responses to chilling were observed. Root pruning decreased and delayed the production of roots <0.6 mm in diameter in response to chilling, while the production of larger roots was less affected. Regeneration of both root types differed among species. For new large (≥ 0.6 mm in diameter) root growth criteria, interactions between chilling hours and species were apparent. Chilling requirements and growing degree hour requirements for vegetative budbreak of each species were estimated.


HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1583-1588 ◽  
Author(s):  
Michael A. Arnold ◽  
Eric Young

Bare-root Malus × domestica Borkh. seedlings were chilled for 0, 600, 1200, or 1800 hours at 5C (CH). Seedlings were then placed with roots and/or shoots in all combinations of 5 and 20C forcing conditions (FC) for up to 21 days. Virtually no growth occurred at 5C FC. When the whole plant was forced at 20C, all measures of root and shoot growth increased in magnitude, occurred earlier and at a faster rate with increasing CH. Thus, roots and shoots responded similarly to chilling. When shoots or roots were subjected to 20C FC, while the other portion of the plant was at 5C, the responses were reduced in magnitude and delayed. However, the overall growth enhancement by chilling was not negated. Root and shoot growth enhancement by chilling appeared to be increased if the other portion of the plant was actively growing also, but not dependent on it. Growth of adventitious shoots on roots (root suckers) was greatly enhanced with increasing CH on plants subjected to 5C shoot and 20C root FC. While total root and shoot bark protein levels on a per-seedling basis were similar, protein concentrations were lower in root bark than in shoot bark. During chilling, total protein per seedling generally increased until just before the time that chilling requirements for vegetative budbreak were satisfied. Protein degradation then began, resulting in lower protein levels through 2300 CH. Rapid protein breakdown (1200 to 1800 CH, roots; 1000 to 1800 CH, shoots) occurred at about the same time that root (1000 to 1800 CH) and shoot (800 to 1800 CH) growth responses to chilling were increasing. Warm FC resulted in increased protein breakdown with increased CH and forcing time.


2000 ◽  
Vol 10 (4) ◽  
pp. 765-767 ◽  
Author(s):  
Timothy K. Broschat ◽  
Kimberly A. Klock-Moore

Areca palms [Dypsis lutescens (H. Wendl.) Beentje & J. Dransf.], spathiphyllums (Spathiphyllum Schott. `Figaro'), ixoras (Ixora L. `Nora Grant'), tomatoes (Lycopersicon esculentum Mill. `Floramerica'), marigolds (Tagetes erecta L. `Inca Gold'), bell peppers (Capsicum annuum L. `Better Bell'), and pentas [Pentas lanceolata (Forssk.) Deflers. `Cranberry'] were grown in a pine bark-based potting substrate and were fertilized weekly with 0, 8, 16, 32, or 64 mg (1.0 oz = 28,350 mg) of P per pot. Shoot, and to a much lesser extent, root dry weight, increased for all species as weekly P fertilization rate was increased from 0 to 8 mg/pot. As P fertilization was increased from 8 to 64 mg/pot, neither roots nor shoots of most species showed any additional growth in response to increased P. Root to shoot ratio decreased sharply as P fertilization rate was increased from 0 to 8 mg/pot, but remained relatively constant in response to further increases in P fertilization rate.


2016 ◽  
Vol 5 (12) ◽  
pp. 5179
Author(s):  
Ilahi Shaik* ◽  
P. Janakiram ◽  
Sujatha L. ◽  
Sushma Chandra

Indole acetic acid is a natural phytohormone which influence the root and shoot growth of the plants. Six (GM1-GM6) endosymbiotic bacteria are isolated from Gracilaria corticata and screened for the production of IAA out of six, three bacterial strains GM3, GM5 and GM6 produced significant amount of IAA 102.4 µg/ml 89.40 µg/ml 109.43 µg/ml respectively. Presence of IAA in culture filtrate of the above strains is further analyzed and confirmed by TLC. As these bacterial strains, able to tolerate the high salinity these can be effectively used as PGR to increase the crop yield in saline soils.


2007 ◽  
Vol 34 (12) ◽  
pp. 1137 ◽  
Author(s):  
Brian J. Atwell ◽  
Martin L. Henery ◽  
Gordon S. Rogers ◽  
Saman P. Seneweera ◽  
Marie Treadwell ◽  
...  

We report on the relationship between growth, partitioning of shoot biomass and hydraulic development of Eucalyptus tereticornis Sm. grown in glasshouses for six months. Close coordination of stem vascular capacity and shoot architecture is vital for survival of eucalypts, especially as developing trees are increasingly subjected to spasmodic droughts and rising atmospheric CO2 levels. Trees were exposed to constant soil moisture deficits in 45 L pots (30–50% below field capacity), while atmospheric CO2 was raised to 700 μL CO2 L–1 in matched glasshouses using a hierarchical, multi-factorial design. Enrichment with CO2 stimulated shoot growth rates for 12–15 weeks in well-watered trees but after six months of CO2 enrichment, shoot biomasses were not significantly heavier (30% stimulation) in ambient conditions. By contrast, constant drought arrested shoot growth after 20 weeks under ambient conditions, whereas elevated CO2 sustained growth in drought and ultimately doubled the shoot biomass relative to ambient conditions. These growth responses were achieved through an enhancement of lateral branching up to 8-fold due to CO2 enrichment. In spite of larger transpiring canopies, CO2 enrichment also improved the daytime water status of leaves of droughted trees. Stem xylem development was highly regulated, with vessels per unit area and cross sectional area of xylem vessels in stems correlated inversely across all treatments. Furthermore, vessel numbers related to the numbers of leaves on lateral branches, broadly supporting predictions arising from Pipe Model Theory that the area of conducting tissue should correlate with leaf area. Diminished water use of trees in drought coincided with a population of narrower xylem vessels, constraining hydraulic capacity of stems. Commensurate with the positive effects of elevated CO2 on growth, development and leaf water relations of droughted trees, the capacity for long-distance water transport also increased.


Geoderma ◽  
2016 ◽  
Vol 265 ◽  
pp. 1-5 ◽  
Author(s):  
J. Lipiec ◽  
A. Siczek ◽  
A. Sochan ◽  
A. Bieganowski

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