scholarly journals MINIMIZING CORKY ROOT DESTRUCTION OF LETTUCE ROOT SYSTEMS BY THE USE OF TRANSPLANTS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 664a-664
Author(s):  
Frank J. Coale ◽  
Russell T. Naqata ◽  
Lawrence E. Datnoff
Keyword(s):  
Root Length ◽  
Lateral Root ◽  
Management Strategies ◽  
Root Systems ◽  
Lateral Root Development ◽  
Corky Root ◽  
Infested Field ◽  
Direct Seeded ◽  
The Impact ◽  
Lateral Root Length

Corky root (CR) of lettuce (Lactuca sativa L.) is caused by the bacterium Rhizomonas suberifaciens. Current management strategies involve the use of resistant cultivars and crop rotation. The use of transplants as a method to grow CR-susceptible cultivars in CR-infested fields was recently demonstrated. The objective of this study was to evaluate corky root destruction of root systems of direct-seeded and transplanted lettuce. Direct seeded, and three and five week old transplants of CR susceptible `Shawnee' and CR resistant `South Bay' crisphead lettuce were grown in a naturally CR-infested field. Root systems were evaluated at head harvest maturity. When direct seeded, South Bay developed 104% more total lateral root length than did Shawnee. When transplanted at three and five weeks, South Bay developed 50% and 61% more total lateral root length than Shawnee, respectively. Total lateral root length for Shawnee transplanted at five weeks was 100% greater than direct seeded Shawnee. Comparatively, total lateral root length for South Bay transplanted at five weeks was 58% greater than direct seeded South Bay. Tap root lengths and dry weights were not different among planting systems. Transplanting is a possible method for reducing the impact of CR on lettuce lateral root development.

NaCl salinity affects lateral root development in Plantago maritima

2004 ◽  
Vol 31 (8) ◽  
pp. 775 ◽  
Author(s):  
Michael Rubinigg ◽  
Julia Wenisch ◽  
J. Theo M. Elzenga ◽  
Ineke Stulen
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Root Length ◽  
Lateral Root ◽  
Lateral Roots ◽  
Third Order ◽  
Lateral Root Primordia ◽  
Relative Growth ◽  
Length Growth ◽  
Lateral Root Length

Root growth and morphology were assessed weekly in hydroponically-grown seedlings of the halophyte Plantago maritima L. during exposure to 0, 50, 100 and 200 mm NaCl for 21 d. Relative growth rate was reduced by 25% at 200 mm NaCl. The lower NaCl treatments did not affect relative growth rates. Primary and lateral roots responded differently to NaCl. While primary-root length increased at all NaCl concentrations, total lateral-root length increased at 50 and was not affected at 100 mm but was considerably reduced at 200 mm NaCl. NaCl concentrations of 50 and 100 mm, which had no effect on relative growth rate or total lateral-root length, severely affected root branching pattern in that the number of first, second and third order laterals was reduced. At 200 mm NaCl third order laterals were not formed at all. However, mean lateral-root length was increased at all NaCl concentrations and was highest at 200 mm NaCl. We conclude that the increase in total lateral-root length in plants at 50 and 100 mm NaCl was mainly caused by increased length growth, while the decrease in total lateral-root length at 200 mm was the consequence of inhibition of lateral root primordia and / or the activation of apical meristems rather than reduced length growth.

Response of Selected Soybean (Glycine max) Cultivars to Dimethenamid and Metolachlor in Hydroponic Conditions

1995 ◽  
Vol 9 (1) ◽  
pp. 178-181 ◽  
Author(s):  
Bradley T. Osborne ◽  
David R. Shaw ◽  
Randall L. Ratliff
Keyword(s):  
Glycine Max ◽  
Root Length ◽  
Lateral Root ◽  
Lateral Roots ◽  
Hydroponic Culture ◽  
Soybean Cultivars ◽  
Length Reduction ◽  
Hydroponic Conditions ◽  
Lateral Root Length

Soybean cultivars were grown in a hydroponic culture to evaluate tolerance to dimethenamid and metolachlor. Root length was reduced in 7 of the 32 cultivars with 50 ppb dimethenamid. ‘Asgrow 5403’ and ‘Bryan’ root lengths were reduced more than 20%. ‘Asgrow 6297’ was the only cultivar with greater than 12% root length reductions with 83 ppb metolachlor. The longest lateral root of all cultivars was shortened with dimethenamid. ‘NK-1460’ and Bryan expressed the most lateral root length reduction, at 73 and 62%, respectively. Asgrow 6297 was tolerant to dimethenamid, but lateral roots were reduced 16%. Metolachlor reduced the lateral root lengths of 12 cultivars, with Asgrow 5403, ‘Coker 6955,’ and Bryan reduced more than 20%. Bryan was the most sensitive cultivar to both herbicides, while ‘Brim’ was the most tolerant of cultivars evaluated.

Pisolithus tinctorius forms long ectomycorrhizae and alters root development in seedlings of Pinus resinosa

1981 ◽  
Vol 59 (11) ◽  
pp. 2129-2134 ◽  
Author(s):  
Richard F. Sohn
Keyword(s):  
Growth Rate ◽  
Root Development ◽  
Lateral Root ◽  
Pinus Resinosa ◽  
Root Systems ◽  
Pisolithus Tinctorius ◽  
Third Order ◽  
Lateral Root Development ◽  
Mycorrhiza Formation

Ectomycorrhizae were synthesized on Pinus resinosa seedlings with Pisolithus tinctorius under aseptic, controlled environmental conditions. Root systems were harvested at 4, 6, and 15 weeks after seed germination. All roots were classified as either long or short and were examined for ectomycorrhiza development. Mycorrhizae were classified as "long mycorrhizae" or "short mycorrhizae," depending upon the type of root where infection occurred.Long mycorrhizae predominated at the early harvests and remained prominent at 15 weeks. A Hartig net of long mycorrhizae formed a morphological continuum from thin to thick. Negative correlations were observed between long mycorrhiza growth rate and the extent of infection. This suggests that a threshold growth rate exists below which mycorrhiza formation occurs readily, but above which mycorrhiza formation is progressively diminished. Relative to the controls, P. tinctorius inoculation increased the ratio of second- and third-order short roots to long roots. The role of host and fungus in controlling lateral root development is discussed.

scholarly journals Interactions between magnesium, calcium, and aluminum on soybean root elongation

2005 ◽  
Vol 29 (5) ◽  
pp. 747-754 ◽  
Author(s):  
Ivo Ribeiro da Silva ◽  
Armando Ferrufino ◽  
Cláudio Sanzonowicz ◽  
Thomas Jot Smyth ◽  
Daniel W. Israel ◽  
...  
Keyword(s):  
Root Length ◽  
Lateral Root ◽  
Root Elongation ◽  
Root Surface ◽  
Al Tolerance ◽  
Split Root System ◽  
Tap Root ◽  
Glycine Max L ◽  
Al Additions ◽  
Lateral Root Length

Alleviation of Al rhizotoxicity by Ca and Mg can differ among species and genotypes. Root elongation of soybean [Glycine max (L.) Merr.] line N93-S-179 and cvs. Young and Ransom exposed to varying concentrations of Al, Ca and Mg were compared in two experiments using a vertically split root system. Roots extending from a surface compartment with limed soil grew for 12 days into a subsurface compartment with nutrient solution treatments maintained at pH 4.6 with either 0 or 15 µmol L-1 Al. Calcium and Mg concentrations in treatments ranging from 0 to 20 mmol L-1. Although an adequate supply of Mg was provided in the surface soil compartment for soybean top growth, an inclusion of Mg was necessary in the subsurface solutions to promote root elongation in both the presence and absence of Al. In the absence of Al in the subsurface solution, tap root length increased by 74 % and lateral root length tripled when Mg in the solutions was increased from 0 to either 2 or 10 mmol L-1. In the presence of 15 µmol L-1 Al, additions of 2 or 10 mmol L-1 Mg increased tap root length fourfold and lateral root length by a factor of 65. This high efficacy of Mg may have masked differences in Al tolerance between genotypes N93 and Young. Magnesium was more effective than Ca in alleviating Al rhizotoxicity, and its ameliorative properties could not be accounted for by estimated electrostatic changes in root membrane potential and Al3+ activity at the root surface. The physiological mechanisms of Mg alleviation of Al injury in roots, however, are not known.

scholarly journals Comparisons of Root Morphology in Susceptible and Tolerant Melon Cultivars before and after Infection by Monosporascus cannonballus

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 681-683 ◽  
Author(s):  
Kevin Crosby ◽  
David Wolff ◽  
Marvin Miller
Keyword(s):  
Root Length ◽  
Root Rot ◽  
Growth Period ◽  
Root Systems ◽  
Root Tip ◽  
Total Root Length ◽  
Root Tips ◽  
Monosporascus Cannonballus ◽  
Vine Decline ◽  
The Impact

The fungus Monosporascus cannonballus Pollock and Uecker infects melon (Cucumis melo L.) roots and causes root rot/vine decline disease, which has reduced productivity of commercial muskmelon and honeydew cultivars in South Texas. To assess the impact of the fungus on several root traits, two greenhouse experiments were carried out over two seasons. A comparison of inoculated vs. control root systems was carried out with four melon cultivars representing both susceptible (`Magnum 45' and `Caravelle') and tolerant types (`Deltex' and `Doublon'). The sand medium was inoculated with 50–60 colony forming units (CFUs) per gram of the severe Monosporascus strain, TX90-25. After a 30-day growth period, the control and inoculated root systems were carefully cleaned and evaluated. Roots were scanned by a computer and the data were analyzed by the Rhizo Pro 3.8 program. The traits of interest included total root length, average root diameter, number of root tips, number of fine roots (0–0.5 mm), and number of small roots (0.5–1 mm). Significant differences existed between the two tolerant cultivars and the two susceptible ones for four of the traits. Total root length, fine and small root length, and root tip number were greater for `Deltex' than for both susceptible cultivars and greater for `Doublon' than for `Caravelle'. The results suggest that tolerance to this pathogen is closely linked to the integrity of the root structure. The potential for improving root vigor to combat root rot/vine decline merits further investigation.

scholarly journals Response of Hybrid Tomato (Solanum lycopersiucm L) for Calcium Nutrition: Growth, Root Traits and SPAD Index

2021 ◽  
pp. 117-123
Author(s):  
S. Salma Santhosh ◽  
T. Chitdeshwari ◽  
D. Jegadeeswari ◽  
C. Kavitha
Keyword(s):  
Root Length ◽  
Lateral Root ◽  
Block Design ◽  
Poultry Manure ◽  
Root Traits ◽  
Growth Stages ◽  
Randomized Block Design ◽  
Calcium Sources ◽  
Different Growth Stages ◽  
Lateral Root Length

Aims: To evaluate the effect of various sources and levels of calcium fertilisation in improving the growth and SPAD index of hybrid tomato at different growth stages. Study Design: Factorial randomized block design (FRBD) with three replications. Place and Duration of Study: A field experiment was conducted in the farmer’s field at Devarayapuram village, Thondamuthur block, Coimbatore from January to April, 2021. Methodology: A field experiment was conducted with hybrid tomato (Solanum lycopersiucm L) Shivam by using various organic and inorganic calcium sources viz., calcium sulphate, calcium nitrate, calcium silicate, poultry manure and pressmud applied at different levels (0, 20, 40, 60, 80 kg Ca ha-1) in a factorial randomized block design with three replications. The growth parameters such as plant height, root length, lateral root length, root volume and SPAD index were recorded as per standard protocols at different plant growth stages. Results: A linear increase in the plant growth, root traits and SPAD index of hybrid tomato was noted by the addition of organic and inorganic sources of calcium and the highest values were observed with the application of 80 kg Ca ha-1. Higher plant height (93.8 cm), root length (16.8 cm), lateral root length (13.3 g cc-1) and SPAD index (62.0) was registered with poultry manure applied at 80 kg Ca ha-1 which was followed by pressmud applied at the same level. Skipping of calcium in the fertiliser schedule registered the lowest growth response of hybrid tomato at all the growth stages. Conclusion: Inorganic Ca fertiliser sources though improved the growth, root traits and SPAD index of hybrid tomato at different growth stages, and it was comparatively lesser than the organic sources such as poultry manure and pressmud as calcium sources. The order of better growth performance was: Poultry manure > Pressmud > Ca silicate > Ca Nitrate > Ca sulphate. The lowest values of all the growth attributes were noted with NPK control. It was concluded that application of poultry manure at 80 kg Ca ha-1 would be effective in improving the growth, root traits and SPAD index of hybrid tomato.

scholarly journals Variation in Root System Architecture among the Founder Parents of Two 8-way MAGIC Wheat Populations for Selection in Breeding

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2452
Author(s):  
Shree R. Pariyar ◽  
Kerstin A. Nagel ◽  
Jonas Lentz ◽  
Anna Galinski ◽  
Jens Wilhelm ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Root Length ◽  
Lateral Root ◽  
Crop Productivity ◽  
Root System Architecture ◽  
Leaf Length ◽  
Time Resolved ◽  
Root Angle ◽  
Lateral Root Length

Root system architecture (RSA) is a target for breeding crops with effective nutrient and water use. Breeding can use populations designed to map quantitative trait loci (QTL). Here we non-invasively phenotype roots and leaves of the 16 foundation parents of two multi-parent advanced generation inter-cross (MAGIC) populations, covering diversity in spring (CSIRO MAGIC) and winter (NIAB MAGIC) wheats. RSA components varied after 16 days in the upgraded, paper-based imaging platform, GrowScreen-PaGe: lateral root length 2.2 fold; total root length, 1.9 fold; and seminal root angle 1.2 fold. RSA components total and lateral root length had the highest root heritabilities (H2) (H2 = 0.4 for CSIRO and NIAB parents) and good repeatability (r = 0.7) in the GrowScreen-PaGe. These can be combined with leaf length (H2 = 0.8 CSIRO; 0.7 NIAB) and number (H2 = 0.6 CSIRO; 0.7 NIAB) to identify root and shoot QTL to breed for wheats with vigorous RSA and shoot growth at establishment, a critical phase for crop productivity. Time resolved phenotyping of MAGIC wheats also revealed parents to cross in future for growth rate traits (fastest: Robigus–NIAB and AC Barrie–CSIRO; slowest Rialto–NIAB and G204 Xiaoyan54–CSIRO) and root: shoot allocation traits (fast growers grew roots, notably laterals, quicker than leaves, compared to slow growers).

scholarly journals High throughput phenotyping of root growth dynamics, lateral root formation, root architecture and root hair development enabled by PlaRoM

2009 ◽  
Vol 36 (11) ◽  
pp. 938 ◽  
Author(s):  
Nima Yazdanbakhsh ◽  
Joachim Fisahn
Keyword(s):  
Root Growth ◽  
Growth Kinetics ◽  
Lateral Root ◽  
Root Architecture ◽  
Imaging Techniques ◽  
Plant Root ◽  
Primary Root ◽  
Growth Media ◽  
Root Extension ◽  
Lateral Root Development

Plant organ phenotyping by non-invasive video imaging techniques provides a powerful tool to assess physiological traits and biomass production. We describe here a range of applications of a recently developed plant root monitoring platform (PlaRoM). PlaRoM consists of an imaging platform and a root extension profiling software application. This platform has been developed for multi parallel recordings of root growth phenotypes of up to 50 individual seedlings over several days, with high spatial and temporal resolution. PlaRoM can investigate root extension profiles of different genotypes in various growth conditions (e.g. light protocol, temperature, growth media). In particular, we present primary root growth kinetics that was collected over several days. Furthermore, addition of 0.01% sucrose to the growth medium provided sufficient carbohydrates to maintain reduced growth rates in extended nights. Further analysis of records obtained from the imaging platform revealed that lateral root development exhibits similar growth kinetics to the primary root, but that root hairs develop in a faster rate. The compatibility of PlaRoM with currently accessible software packages for studying root architecture will be discussed. We are aiming for a global application of our collected root images to analytical tools provided in remote locations.

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