Root development in seedlings of ryegrass (Lolium perenne L.) and phalaris (Phalaris aquatica L.) sown onto the soil surface

1982 ◽  
Vol 33 (4) ◽  
pp. 665 ◽  
Author(s):  
PS Cornish
Keyword(s):  
Root Development ◽  
Soil Surface ◽  
Undisturbed Soil ◽  
Growth And Survival ◽  
Small Vessels ◽  
Nodal Roots ◽  
Nodal Root ◽  
Seminal Roots ◽  
Surface Drying ◽  
Axial Resistance

The effects of surface-sowing on root type, number and xylem radius were studied in relation to the seedling growth and survival of ryegrass and phalaris. Under optimal conditions in a growth cabinet, both species produced primary and lateral seminal roots, nodal roots and, in the absence of light, a subcoleoptile internode (s.c.i.). Phalaris had fewer lateral seminal roots and, in this species, internodal roots occurred along the s.c.i. Surface placement per se had no effect on any of the measured parameters of root development, but surface drying prevented nodal root primordia from extending, even when plants were otherwise supplied with water. This effect of surface drying on nodal root development was confirmed in a glasshouse study using undisturbed soil cores (30 by 60 cm) to simulate field conditions. Phalaris was less likely than ryegrass to produce nodal roots after surface sowing. The effective xylem radius (re) of the primary seminal root was 7.9 �m in ryegrass and 11.6 �m in phalaris. Calculations using the Poiseuille equation indicated that the axial resistance to water flow through these roots would greatly restrict seedling water uptake and growth in the absence of other roots. Lateral seminal roots and internodal roots had small vessels which could not significantly reduce the axial resistance to flow. Good seedling water relations in both species therefore depend on early development of the nodal roots which contain large xylem vessels (re > 16 �m). It was concluded that the effect of soil-surface drying on nodal root development was likely to account for some cases of poor vigour and survival of surface-sown grasses.

Water Stressed Nodal Roots of Wheat: Effects on Leaf Growth

1997 ◽  
Vol 24 (1) ◽  
pp. 49 ◽  
Author(s):  
K. M. Volkmar
Keyword(s):  
Growth Rate ◽  
Water Content ◽  
Relative Water Content ◽  
Leaf Growth ◽  
Seminal Root ◽  
Nodal Roots ◽  
Nodal Root ◽  
Relative Water ◽  
Seminal Roots ◽  
Leaf Relative Water Content

This experiment as undertaken to determine the efects of soil drying around the nodal and/or seminal root systems on the shoot growth of wheat (Triticum aestivum L.). Two split-root experiments were conducted, the first on newly emerged nodal roots of 18-day-old wheat plants, the second on 25-day-old plants. In both experiments, nodal and seminal roots were isolated from one another and water was withheld from either the nodal root chamber, the seminal root chamber, or both, over 6 days. In the first experiment, leaf growth was unaffected by withholding water from very short nodal roots, even though leaf relative water content of the droughted plants decreased. By comparison, both leaf elongation rate and relative water content decreased by withholding water from the seminal roots. On plants that were 1 week older, leaf growth rate and leaf relative water content decreased when nodal roots were drought-stressed. Leaf growth rate of seminal root droughted plants was more impaired than their nodal root counterparts, even though leaf relative water contents of the two treatments were the same. In both experiments, drought stress applied to the nodal root system enhanced nodal root growth more than seminal roots. These results suggest that seminal and nodal roots perceive and respond to drought stress differently with respect to the nature of the message conveyed to the shoots.

scholarly journals Use of Transcriptomic Analyses to Elucidate the Mechanism Governing Nodal Root Development in Eremochloa ophiuroides (Munro) Hack.

2021 ◽  
Vol 12 ◽  
Author(s):  
Rui Wang ◽  
Haoyan Zhao ◽  
Hailin Guo ◽  
Junqin Zong ◽  
Jianjian Li ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Transcription Factors ◽  
Root Development ◽  
Molecular Mechanisms ◽  
Homologous Gene ◽  
Root Tips ◽  
Rooting Ability ◽  
Nodal Roots ◽  
Nodal Root ◽  
Eremochloa Ophiuroides

Centipedegrass [Eremochloa ophiuroides (Munro) Hack.] is a perennial warm-season grass that originated in China, and its speed of nodal rooting is important for lawn establishment. In our study, centipedegrass nodal rooting ability was limited by node aging. Transcriptome sequencing of nodal roots after 0, 2, 4, and 8 days of water culture was performed to investigate the molecular mechanisms of root development. GO enrichment and KEGG pathway analyses of DEGs indicated that plant hormone signal transduction and transcription factors might play important roles in centipedegrass nodal root growth. Among them, E3 ubiquitin-protein ligases participated in multiple hormone signal transduction pathways and interacted with transcription factors. Furthermore, an E3 ubiquitin protein ligase EoSINAT5 overexpressed in rice resulted in longer roots and more numerous root tips, while knockout of LOC_Os07g46560 (the homologous gene of EoSINAT5 in rice) resulted in shorter roots and fewer root tips. These results indicated that EoSINAT5 and its homologous gene are able to promote nodal root development. This research presents the transcriptomic analyses of centipedegrass nodal roots, and may contribute to elucidating the mechanism governing the development of nodal roots and facilitates the use of molecular breeding in improving rooting ability.

Effect of nitrogen and phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1989 ◽  
Vol 40 (3) ◽  
pp. 489 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Root System ◽  
Phosphorus Deficiency ◽  
Gaeumannomyces Graminis ◽  
Nitrogen And Phosphorus ◽  
Nodal Roots ◽  
Proximal Lesion ◽  
Nodal Root ◽  
Seminal Roots ◽  
Four Levels ◽  
Take All

Wheat was grown in a slightly acid grey sand at six levels of phosphorus and four levels of nitrogen, in the presence and absence of inoculum of Gaeurnannomyces graminis tritici (Ggt) in a glasshouse experiment. Adequate nutrition of N (400 mg/pot) and P (100 mg/pot) for wheat plants was required to overcome take-all of wheat grown for 46 days. Severely N and P deficient plants had 60% of their seminal and nodal roots infected by take-all. As the plants responded to increasing levels of N and P, the percentage of infected nodal and seminal roots steadily declined to 0% and 10% for each root system respectively at luxury levels of P and adequate N. In both the seminal and nodal root system, increasing the N and P supply decreased the length of proximal lesions (closest to seed) and increased the length of the root between the crown and the proximal lesion. The seminal root system was more severely infected with take-all than the nodal root system.

Effect of phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1988 ◽  
Vol 39 (4) ◽  
pp. 541 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Phosphorus Deficiency ◽  
Root Systems ◽  
Gaeumannomyces Graminis ◽  
Nodal Roots ◽  
Nodal Root ◽  
Seminal Roots ◽  
Phosphorus Status ◽  
Gaeumannomyces Graminis Var Tritici ◽  
P Supply ◽  
Take All

Wheat was grown in a slightly acidic grey sand at six levels of phosphorus, in the presence or absence of take-all inoculum in a glasshouse experiment. The incidence and severity of take-all was related to the phosphorus supply and the phosphorus status of wheat.Plants grown without P were more severely infected by take-all than those grown at adequate levels of phosphorus. The percentage of both nodal and seminal roots infected by take-all declined as the level of P was increased. The percentage of seminal roots infected was reduced from 35% to 13.7% by increasing the supply of phosphorus from levels severely deficient to those adequate for plant growth. Infection in nodal roots was reduced from 24% to 2.3% as the P supply increased. In both the seminal and nodal root systems, increasing the P supply decreased the length of proximal lesions (closest to seed) and increased the length of root between the crown and the proximal lesions.

scholarly journals The developmental pattern of roots and shoots of oats under favourable conditions.

1970 ◽  
Vol 18 (3) ◽  
pp. 168-181
Author(s):  
J.J. Schuurman ◽  
J.J.H. De Boer
Keyword(s):  
Shoot Growth ◽  
Soil Surface ◽  
Experimental Period ◽  
Maximum Weight ◽  
Nodal Roots ◽  
Natural Rainfall ◽  
Developmental Growth ◽  
Root And Shoot Growth ◽  
Seminal Roots ◽  
Generative Stage

Oats were sown on 24 Mar. in asbestos tubes 75 cm long and 15 cm in diameter filled with humus sand and placed in the open. The water level in the soil profile was maintained at about 70 cm below the soil surface by natural rainfall and by a controlled water supply from shallow dishes in which the tubes stood. Plants were sampled in duplicate at weekly intervals between 13 May and 15 July and the developmental growth pattern of shoots and seminal and nodal roots was examined. The total weight of nodal roots increased until the plant had attained its maximum shoot length, and until about 5 weeks after the last leaf appeared on 26 May. Weights and DM content of the shoots increased over the whole of the experimental period. The greatest number of nodal roots was initiated during 3-10 June, between the end of tillering and the beginning of panicle emergence; after that the numbers initiated per week decreased gradually. The number of seminal roots varied between 4 and 5 per plant and reached their maximum weight just after the end of tillering and before the panicles became visible. After 10 June the weight and growth rate of seminal roots decreased rapidly. Seminal roots and the early initiated nodal roots were the most important part of the root system. In the week before the panicles became visible, root and shoot growth was interrupted; this was thought to be related to the transition from the vegetative to the generative stage. CMC. (Abstract retrieved from CAB Abstracts by CABI’s permission)

CORN RESPONSE TO RESTRICTED NODAL ROOT GROWTH WITH RELEVANCE TO ZERO TILLAGE

1986 ◽  
Vol 66 (4) ◽  
pp. 689-699 ◽  
Author(s):  
D. A. J. BARRY ◽  
M. H. MILLER
Keyword(s):  
Zea Mays ◽  
Root Growth ◽  
Root Development ◽  
Shoot Growth ◽  
Zea Mays L ◽  
Zero Tillage ◽  
Leaf Stage ◽  
Nodal Root ◽  
Seminal Roots ◽  
Dry Soil

In Ontario, corn (Zea mays L.) yields with zero tillage are 10–15% lower than those with conventional tillage. Slower growth with zero tillage usually begins at the four-or five-leaf stage and continues until the 10- to 12-leaf stage. We hypothesized that restriction of nodal root development occurs with zero tillage and causes the reductions in shoot growth and final yield. Two greenhouse experiments were conducted in which nodal root development of corn plants was restricted by soil compaction or dry soil while the seminal roots grew in flowing nutrient culture. Compaction reduced nodal root length by 54%, and dry soil reduced it by 90% at the 10-leaf stage. Shoot dry weight at the 12-leaf stage was significantly reduced by dry soil but not by compaction. Leaf water potential and stomatal conductance at the 12-leaf stage were reduced by dry soil despite a negligible drop in pressure potential across the mesocotyl. Dry soil reduced shoot growth in terms of plant height after the eight-leaf stage. It was concluded that restriction of nodal root growth in zero tillage systems probably would not account for the reduced yields. Key words: Corn, Zea mays L., growth regulator, seminal roots, mesocotyl, xylem resistance

Interactions of surface drying and subsurface nutrients affecting plant growth on acidic soil profiles from an old pasture

1986 ◽  
Vol 26 (6) ◽  
pp. 681 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson
Keyword(s):  
Subsurface Layer ◽  
Acid Soils ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Soil Profiles ◽  
Poor Growth ◽  
South Wales ◽  
Reconstituted Soil ◽  
Subsurface Layers ◽  
Surface Drying

Previous studies on soils from old pastures in southern New South Wales have demonstrated that nutrients have accumulated at the soil surface, but that the 40-100-mm depth layer in many profiles has become strongly acidic (e.g. pH 4.7), and high in extractable aluminium. Poor growth of subterranean clover has occurred on such soils during dry periods and may be associated with poor root growth in the acidic, nutrient-poor subsurface layers. Possible nutritional causes of these observations were investigated using reconstituted soil profiles. The root and shoot growth of subterranean clover, wheat, oats and lucerne were compared in unamended profiles and in profiles amended by applying nutrients or calcium carbonate (lime) to correct the more obvious deficiencies of the subsurface layers. Subterranean clover grew well as long as the surface soil remained moist, so that plants could utilise the nutrients potentially available within it. When the surface (0-40 mm) was allowed to dry but the subsurface layers remained moist, growth was poor unless phosphate was applied to the moist layer. Subsurface application of lime alone was ineffective. Nitrogen application increased clover growth in the presence of added phosphate or surface moisture, but nitrogen alone did little to alleviate the effects of surface drought. Wheat, and to a lesser extent oats, responded to subsurface lime when the surface was moist, and both responded to subsurface phosphate when the surface was dry. Lucerne responded to subsurface phosphate similarly to subterranean clover but the response was more than doubled in the presence of additional borate and lime. Lime without borate was not effective. When the surface was maintained moist, liming both the surface (0-40 mm) and subsurface layers improved the response over liming the subsurface layer only. The results suggest that declining fertility and productivity in old pastures developed on acid soils may not be rectified by liming alone, but that cultivation, ripping or drilling of phosphate, and in some cases addition of borate, may be required to improve the penetration of nutrients, particularly phosphorus, to greater depth.

Response of winter wheat to prolonged waterlogging under outdoor conditions

1981 ◽  
Vol 97 (3) ◽  
pp. 557-568 ◽  
Author(s):  
R. K. Belford
Keyword(s):  
Winter Wheat ◽  
Water Table ◽  
Stem Elongation ◽  
Soil Surface ◽  
Root Production ◽  
Or Efficiency ◽  
Plant Nitrogen ◽  
Stages Of Growth ◽  
Nodal Root ◽  
Waterlogging Treatment

SUMMARYThe response of winter wheat cv. Maris Huntsman to waterlogging was studied in two experiments in soil columns outdoors. Winter waterlogging treatments increased nodal root production and the proportion of aerenchyma within roots, but caused chlorosis and premature senescence of leaves, and decreased tillering. For all treatments, grain losses were much less than expected from the extent of tiller loss in winter; losses after single waterlogging events ranged from 2% (after 47 days with the water-table at 5 cm) to 16% (after 80 days with the water-table at the soil surface). Yield losses after three waterloggings at the seedling, tillering and stem elongation stages of growth were additive, and totalled 19%. In many treatments, grain loss was associated with lighter individual grain weights, suggesting that the size of the root system or efficiency of water and nutrient uptake by roots at the later stages of growth may have been less after earlier waterlogging. The importance of nitrogen fertilizer in maintaining a satisfactory plant nitrogen status was shown when nitrogen was with held before a 3-week waterlogging treatment during stem elongation; tiller and floret survival was subsequently greatly restricted and grain yields decreased 22% below those of plants waterlogged at the same stage of growth but supplied with nitrogen.

scholarly journals DEGRADASI LAHAN PADA KEBUN CAMPURAN DAN TEGALAN DI KABUPATEN DHARMASRAYA

Jurnal Solum ◽  
2007 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Syafrimen Yasin ◽  
Gusnidar Gusnidar ◽  
Dedy Iskandar
Keyword(s):  
Land Use ◽  
Soil Depth ◽  
Soil Surface ◽  
Soil Samples ◽  
Imperata Cylindrica ◽  
Undisturbed Soil ◽  
Fertility Status ◽  
Land Use Types ◽  
Bulk Volume ◽  
Soil Fertility Status

A research conducted in Sungai Rumbai, Dharmasraya Regency and in Soil Laboratory Andalas university was aimed to evaluate soil fertility status on the depth below 0-20 cm from several land use types , especially under Mixed Garden and annual cultivated dryland soil.  Soil samples were taken on Ultisol at 0-8% slope (late-waving soil surface).  Land use types evaluated were forest, annual cultivated dryland, bush land, rangeland covered by Imperata cylindrica and mixed garden.  Composite soil samples for soil chemical analysis were taken on the 0-20 cm soil depth with four replications, and 5 drillings for each replication.  Undisturbed soil samples by using sample ring were used to analyze sol bulk volume.  The data resulted were compared to the criteria and were statistically tested using Analysis of Variance and then were continued by LSD at 5% level.  From the results of analyses could be concluded that land use  for mixed garden had the higher Organic Carbon (OC) content and the lower bulk volume (BV) than those for annual cultivated dryland soil.Key Words: Degradasi Lahan, Kebun Campuran, Tegalan

scholarly journals TRANSFORMATION OF OPEN SOIL SURFACE UNDER THE IMPACT OF RAINFALL IN MODEL EXPERIMENT

2018 ◽  
pp. 23-40 ◽  
Author(s):  
G. V. Vindeker ◽  
E. Yu. Prudnikova ◽  
I. Yu. Savin
Keyword(s):  
Forest Soil ◽  
Model Experiment ◽  
Soil Surface ◽  
Significant Rise ◽  
Leached Chernozem ◽  
Surface Image ◽  
Average Reflectance ◽  
Grey Forest Soil ◽  
Surface Drying ◽  
The Impact

During the model experiment we exposed samples from surface layer of leached chernozem, grey forest and soddy-podzolic soils to study the impact of raindrop action on their surface. According to our results, surface of leached chernozem and grey forest soil transformed similarly forming the crust separated by the cracks. The crust consisted of light (washed silt fraction) and dark (compacted fine material) areas. As for the soddy-podzilic soil, we observed surface accumulation of sand and washed mineral grains. Surface image classification showed that cracks generally tended to increase in area during the surface drying. However, leached chernozem cracked quicker and heavier compared to grey forest soil. In addition, the proportion between light and dark areas of the crust for these two types of soil changed differently as well. In conditions of different transformation cycles divided by heavy rainfalls, the changes of cracks position and the increase of light crust area was observed, while dark area moved to the cracks. Such spatial rearrangement resulted in the increase of average reflectance in RGB channels. The inequality between reflectance in different channels increased as well. During the experiment significant surface lightening occurred. It mainly affected the light area of crust and led to significant rise in reflectance in red channel.

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