Belowground herbivore tolerance involves delayed overcompensatory root regrowth in maize

An optimized cryopreservation protocol for embryonic axes (EAs) of chestnut (Castanea sativa Mill.) has been developed based on the encapsulation–vitrification procedure. EAs of mature seeds were aseptically dissected and encapsulated in alginate beads with or without 0.3% (w/v) activated charcoal (AC). Embedded EAs were dehydrated with Plant Vitrification Solution 2 for different treatment times up to 120 min, followed by direct immersion in liquid nitrogen. Cryopreserved embryonic axes encapsulated with AC showed higher survival (70%) compared to those encapsulated without AC (50%). Sixty-four percent of embryonic axes, from synthetic seeds with AC, subsequently developed as whole plants. Plantlet regrowth was faster in AC-encapsulated EAs and showed enhanced postcryopreservation shoot and root regrowth over 2 cm after five weeks from rewarming. Results indicate that encapsulation–vitrification with activated charcoal added to the beads is an effective method for the long-term preservation of Castaneasativa embryonic axes.

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Genetic variability and inheritance of aluminium tolerance as indicated by long root regrowth in lucerne (Medicago sativa L.)

Euphytica ◽

10.1007/s10681-007-9409-3 ◽

2007 ◽

Vol 157 (1-2) ◽

pp. 177-184 ◽

Cited By ~ 12

Author(s):

Xianguang Zhang ◽

Alan Humphries ◽

Geoff Auricht

Keyword(s):

Genetic Variability ◽

Medicago Sativa ◽

Aluminium Tolerance ◽

Root Regrowth ◽

Medicago Sativa L

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Interlaboratory Validation of Toxicity Testing Using the Duckweed Lemna minor Root-Regrowth Test

Biology ◽

10.3390/biology11010037 ◽

2021 ◽

Vol 11 (1) ◽

pp. 37

Author(s):

Jihae Park ◽

Eun-Jin Yoo ◽

Kisik Shin ◽

Stephen Depuydt ◽

Wei Li ◽

...

Keyword(s):

Natural Waters ◽

Lemna Minor ◽

Toxicity Testing ◽

Test Method ◽

Rapid Screening ◽

The Novel ◽

Root Regrowth ◽

Interlaboratory Validation ◽

Validity Criteria ◽

Slow Moving

The common duckweed (Lemna minor), a freshwater monocot that floats on the surfaces of slow-moving streams and ponds, is commonly used in toxicity testing. The novel Lemna root- regrowth test is a toxicity test performed in replicate test vessels (24-well plates), each containing 3 mL test solution and a 2–3 frond colony. Prior to exposure, roots are excised from the plant, and newly developed roots are measured after 3 days of regrowth. Compared to the three internationally standardized methods, this bioassay is faster (72 h), simpler, more convenient (requiring only a 3-mL) and cheaper. The sensitivity of root regrowth to 3,5-dichlorophenol was statistically the same as using the conventional ISO test method. The results of interlaboratory comparison tests conducted by 10 international institutes showed 21.3% repeatability and 27.2% reproducibility for CuSO4 and 21.28% repeatability and 18.6% reproducibility for wastewater. These validity criteria are well within the generally accepted levels of <30% to 40%, confirming that this test method is acceptable as a standardized biological test and can be used as a regulatory tool. The Lemna root regrowth test complements the lengthier conventional protocols and is suitable for rapid screening of wastewater and priority substances spikes in natural waters.

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The Response of Kentucky Bluegrass to Soil Residues of Preemergence Herbicides

Weed Science ◽

10.1017/s0043174500030782 ◽

1969 ◽

Vol 17 (1) ◽

pp. 13-15 ◽

Cited By ~ 8

Author(s):

G. S. Smith ◽

L. M. Callahan

Keyword(s):

Poa Pratensis ◽

Kentucky Bluegrass ◽

Soil Layers ◽

Root Regrowth ◽

Herbicide Residue ◽

Herbicide Treatments ◽

Chemical Inhibition ◽

Preemergence Herbicides ◽

Field Plots ◽

Soil Level

Common Kentucky bluegrass (Poa pratensis L.) sod-plugs were grown in the greenhouse in soil freshly treated with 11 herbicides and in soil collected from the 0 to 2 and 2 to 4-inch depths of field plots treated 10 months earlier with the same herbicides. Fresh herbicide treatments reduced significantly the root regrowth of the bluegrass plants. The 12-lb/A rate of the fresh application of 1-(2-methylcyclohexyl)-3-phenylurea (siduron) caused the least chemical inhibition of root regrowth. The most phytotoxic fresh applications were 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) and 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), both killing the bluegrass plants at the 4 lb /A rate. Root regrowth of bluegrass grown in the herbicide residue samples was significantly reduced for all treatments. Herbicides which tended to persist in the 0 to 2-inch soil level and were most phytotoxic to root regrowth were simazine, polychlorodicyclopentadiene isomers (hereinafter referred to as bandane), N-(2-mercaptoethyl)-benzenesulfonamide S-(O,O-diisopropyl phosphorodithioate) (bensulide), and 2,6-di-tert-butyl-p-tolyl-methylcarbamate (terbutol). Those herbicides which tended to leach into the 2 to 4-inch soil level and cause the greatest reduction of root regrowth were N-butyl-N-ethyl-alpha, alpha, alpha-trifluoro-2,6-dinitro-p-toluidine (benefin), α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), atrazine, and O-(2,4-dichlorophenyl) O-methyl isopropylphosphoramidothioate (DMPA). Herbicides which tended to leach uniformly throughout the 0 to 2 and 2 to 4-inch soil layers were siduron, an equal mixture of 1,1-dimethyl-4,6-diisopropyl-5-indanyl ethyl ketone and 1,1-dimethyl-4,6-diisopropyl-7-indanyl ethyl ketone (hereinafter referred to as sin-done), and dimethyl 2,3,5,6-tetra-chloroterephthalate (DCPA).

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Impacts of Wire Basket Retention and Removal on Fraxinus americana ‘Autumn Purple’ Growth Nine Years After Transplanting

Arboriculture & Urban Forestry ◽

10.48044/jauf.2019.007 ◽

2019 ◽

Vol 45 (3) ◽

Author(s):

Ryan Klein ◽

Richard Hauer ◽

Andrew Koeser ◽

Bob Bleicher

Keyword(s):

Tree Height ◽

System Stability ◽

P Value ◽

Growth Responses ◽

Fraxinus Americana ◽

Trunk Diameter ◽

Root Regrowth ◽

Planting Material ◽

Surrounding Soil ◽

Wire Basket

The topic of wire basket removal during planting remains an area of contention among nursery growers, landscapers, and arborists who work with balled-and-burlapped planting material. Those in favor of removal fear that the burlap and wire surrounding a tree’s root ball will impede root regrowth and eventually lead to the girdling of any roots that do penetrate into the surrounding soil. Those opposed to removal believe the advantages to tree and root system stability during transplanting and establishment outweigh any negatives to leaving the root ball intact. In 2008, 45 Fraxinus Americana ‘Autumn Purple’ were randomly assigned one of three transplanting treatments: 1) transplanted by tree spade without burlap/wire; 2) transplanted as balled-and-burlapped with only burlap and string removed; or 3) transplanted as balled-and-burlapped with all packaging materials (i.e., string, burlap, wire basket) removed. All trees survived regardless of treatment. In addition to survival, trunk diameter and tree height were measured annually for nine years. Marginal differences were noted for the two growth responses over the course of the trial (min P-value = 0.0599).

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Freezing media affect cooling rate and regrowth of KSC 28 apple rootstock

Canadian Journal of Plant Science ◽

10.4141/p96-171 ◽

1997 ◽

Vol 77 (3) ◽

pp. 469-471 ◽

Cited By ~ 1

Author(s):

Jean-Pierre Privé ◽

Charlie Embree

Keyword(s):

Cooling Rate ◽

Cold Hardiness ◽

Temperature Gradients ◽

Controlled Environment ◽

Uniform Temperature ◽

Apple Rootstock ◽

Cooling Rates ◽

Root Regrowth ◽

Plastic Bag ◽

Environment Chamber

To examine the effect that media have on cooling rates and subsequent plant regrowth, bare-rooted Kentville Select Clone 28 (KSC28) apple (Malus domestica Borkh.) roots were placed in various media (water, sawdust, soilless mixture and plastic bag) and set in a controlled environment chamber preset to −12 °C. Cooling rates differed between media with water and the plastic bag requiring the most and the least time to reach −12 °C, respectively. Shoot and root regrowth were similar for all treatments except water, which was significantly reduced. The plastic bag treatment provided the most uniform temperature gradients throughout the root system and the fastest cooling rate, was the easiest to handle, and allowed good regrowth. Key words: KSC28 apple rootstock, sawdust, soilless mix, cold hardiness testing

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Effect of Cold Storage on Bud Break, Root Regeneration and Shoot Extension of Douglas Fir, Paper Birch and Green Ash

Journal of Environmental Horticulture ◽

10.24266/0738-2898-11.3.119 ◽

1993 ◽

Vol 11 (3) ◽

pp. 119-123

Author(s):

J. Roger Harris ◽

Nina L. Bassuk ◽

Thomas H. Whitlow

Keyword(s):

Cold Storage ◽

Douglas Fir ◽

Extension Rate ◽

Bud Break ◽

Dormancy Release ◽

Green Ash ◽

Storage Duration ◽

Root Regrowth ◽

Root Regeneration ◽

Paper Birch

Abstract Dormancy level, days to bud break, root regrowth and rate of shoot extension were determined for 18-in seedlings of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), paper birch (Betula papyrifera Marsh.) and green ash (Fraxinus pennsylvanica Marsh.) subjected to varying durations of cold storage. Douglas fir seedlings did not break bud unless exposed to at least 4 weeks of cold storage, but bud break was unaffected by further time in cold storage. The number of regenerated roots increased with time in cold storage until 12 weeks of chilling and decreased sharply thereafter. Days to bud break of paper birch and green ash decreased as chilling time accumulated. Full dormancy release and maximum root regeneration of paper birch coincided at 10 weeks of chilling. Green ash achieved full dormancy release after 14 weeks of cold storage. The number of roots regenerated increased with cold storage duration for green ash. Shoot extension rate of all species was little affected by chilling duration. Implications for transplanting are discussed.

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Humic Acid Application Affects Photosynthesis, Root Development, and Nutrient Content of Creeping Bentgrass

HortScience ◽

10.21273/hortsci.33.6.1023 ◽

1998 ◽

Vol 33 (6) ◽

pp. 1023-1025 ◽

Cited By ~ 29

Author(s):

Chunhua Liu ◽

R.J. Cooper ◽

D.C. Bowman

Keyword(s):

Humic Acid ◽

Chlorophyll Concentration ◽

Net Photosynthesis ◽

Creeping Bentgrass ◽

Nutrient Content ◽

Agrostis Stolonifera ◽

Root Mass ◽

Tissue Concentrations ◽

Commercial Preparation ◽

Root Regrowth

Humic acids (HA) reportedly enhance the growth of numerous crops; however, little information is available as to their effects on turfgrasses. Experiments were conducted to evaluate the effect of a commercial preparation of HA on the photosynthesis, chlorophyll concentration, rooting, and nutrient content of `Crenshaw' creeping bentgrass (Agrostis stolonifera L.). Bentgrass plugs were grown hydroponically in one-quarter-strength Hoagland's nutrient solution containing HA at 0, 100, 200, or 400 mg·L-1 with measurements made weekly for 1 month. The photosynthetic rates of plants growing in 100 or 200 mg·L-1 rarely differed from that of the control, but 400 mg·L-1 significantly enhanced net photosynthesis on all four observation dates. Chlorophyll content was unaffected by HA rate on all observation dates. Root dehydrogenase (DH) activity and root mass regrowth were significantly increased by HA at 400 mg·L-1 on all dates. The 100 and 200 mg·L-1 rates increased root DH activity on two of four observation dates, but root regrowth was unaffected. At one or more of the rates used, HA increased tissue concentrations of Mg, Mn, and S and decreased those of Ca, Cu, and N, but had no influence on the concentrations of P, K, Fe, Mo, and Zn.

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Tolerance of aluminium toxicity in annual Medicago species and lucerne

Australian Journal of Experimental Agriculture ◽

10.1071/ea07137 ◽

2008 ◽

Vol 48 (4) ◽

pp. 499 ◽

Cited By ~ 23

Author(s):

B. J. Scott ◽

M. A. Ewing ◽

R. Williams ◽

A. W. Humphries ◽

N. E. Coombes

Keyword(s):

Average Length ◽

Aluminium Toxicity ◽

Solution Culture ◽

Al Tolerance ◽

Physiological Basis ◽

Root Regrowth ◽

Selection Intensities ◽

Annual Medicago ◽

Medicago Species ◽

Relative Root

A rapid (7 day) solution-based screening test was developed using 15 annual Medicago cultivars and one M. sativa. Based on a relative root regrowth after exposures to aluminium (Al), Zodiac (M. murex), Orion (M. sphaerocarpos) and the M. polymorha cultivars Santiago, Cavalier and Serena had the greatest Al tolerance. Herald (M. littoralis) and Rivoli (M. tornata) were most sensitive. Ranking for Al tolerance from the solution culture correlated well (r = 0.80) with ranking for tolerance of the 16 genotypes grown in an acidic soil (unlimed pHCa 4.1). We screened 17 Australian populations of lucerne (M. sativa) using a 24 h ‘pulse’ of 75 µmol/L Al, and a three day ‘recovery’ of 10 µmol/L Al. We identified and recovered plants with a root regrowth of ≥5 mm in all 17 populations with selection intensities of 2 to 4%. Four of these selected populations (Aurora, UQL-1, A513 and TO2-011) were polycrossed within each population to produce four populations of seed from the cycle 1 selections. The length of root regrowth under Al stress was improved for all four populations of cycle 1 selection (P ≤ 0.001; from 2.6 mm for the original populations to 6.3 mm for the cycle 1 selections). In a subsequent experiment the cycle 2 selections from Aurora, UQL-1 and TO2-011 had significantly greater root regrowth than both the cycle 1 selections (P ≤ 0.001; 8.3 cf. 6.6 mm) and the unselected populations (3.0 mm). The selections from TO2-011 appeared to have greater improvement in the average length of root regrowth after 2 cycles of selection. Selected germplasm was more tolerant than GAAT in our evaluation. Based on estimation of realised heritability, it seemed likely that higher selection intensities would give more rapid improvements in tolerance. Our studies have not investigated the physiological basis of any tolerance of Al which we observed.

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