Growth direction of nodal roots in rice: its variation and contribution to root system formation

1994 ◽  
Vol 165 (2) ◽  
pp. 333-337 ◽  
Author(s):  
Jun Abe ◽  
Shigenori Morita
Keyword(s):  
Root System ◽  
Growth Direction ◽  
System Formation ◽  
Nodal Roots

scholarly journals Studies on Root System Formation in Rice Plants in a Paddy

1963 ◽  
Vol 32 (2) ◽  
pp. 163-180 ◽  
Author(s):  
Shin-ichiro KAWATA ◽  
Koou YAMAZAKI ◽  
Kuni ISHIHARA ◽  
Hidejiro SHIBAYAMA ◽  
Kwan-Long LAI
Keyword(s):  
Root System ◽  
Rice Plants ◽  
System Formation

scholarly journals Influences of irrigating methods on growth and root system formation of summer cropping melon cultivated under root confinement in a vinyl house

Root Research ◽  
2007 ◽  
Vol 16 (2) ◽  
pp. 39-45
Author(s):  
Masataka YAMASHITA ◽  
Masuo NITTA ◽  
Yoichi ARAKI
Keyword(s):  
Root System ◽  
System Formation

scholarly journals Cost-Benefit Analysis of the Upland-Rice Root Architecture in Relation to Phosphate: 3D Simulations Highlight the Importance of S-Type Lateral Roots for Reducing the Pay-Off Time

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel Gonzalez ◽  
Johannes Postma ◽  
Matthias Wissuwa
Keyword(s):  
Root System ◽  
Lateral Roots ◽  
Root Hairs ◽  
P Uptake ◽  
Root Tissue ◽  
Rice Root ◽  
P Deficiency ◽  
Nodal Roots ◽  
Nodal Root ◽  
Off Time

The rice root system develops a large number of nodal roots from which two types of lateral roots branch out, large L-types and fine S-types, the latter being unique to the species. All roots including S-types are covered by root hairs. To what extent these fine structures contribute to phosphate (P) uptake under P deficiency was investigated using a novel 3-D root growth model that treats root hairs as individual structures with their own Michaelis-Menten uptake kinetics. Model simulations indicated that nodal roots contribute most to P uptake followed by L-type lateral roots and S-type laterals and root hairs. This is due to the much larger root surface area of thicker nodal roots. This thickness, however, also meant that the investment in terms of P needed for producing nodal roots was very large. Simulations relating P costs and time needed to recover that cost through P uptake suggest that producing nodal roots represents a considerable burden to a P-starved plant, with more than 20 times longer pay-off time compared to S-type laterals and root hairs. We estimated that the P cost of these fine root structures is low enough to be recovered within a day of their formation. These results expose a dilemma in terms of optimizing root system architecture to overcome P deficiency: P uptake could be maximized by developing more nodal root tissue, but when P is growth-limiting, adding more nodal root tissue represents an inefficient use of the limiting factor P. In order to improve adaption to P deficiency in rice breeding two complementary strategies seem to exist: (1) decreasing the cost or pay-off time of nodal roots and (2) increase the biomass allocation to S-type roots and root hairs. To what extent genotypic variation exists within the rice gene pool for either strategy should be investigated.

scholarly journals Root Confinement Effects on Strawberry (Fragaria*ananassa Duch.) Growth and Root System Formation

Root Research ◽  
2008 ◽  
Vol 17 (3) ◽  
pp. 99-104
Author(s):  
Masataka YAMASHITA ◽  
Makoto OKIMURA
Keyword(s):  
Root System ◽  
Fragaria Ananassa ◽  
Confinement Effects ◽  
System Formation

Réaction géotropique des différents types de racines chez l'hévéa (Hevea brasiliensis)

1996 ◽  
Vol 74 (12) ◽  
pp. 1910-1918 ◽  
Author(s):  
Yannick Le Roux ◽  
Loïc Pagès
Keyword(s):  
Root System ◽  
Hevea Brasiliensis ◽  
Vertical Plane ◽  
Growth Direction ◽  
Vertical Position ◽  
Different Types ◽  
Original Direction ◽  
Growth Development ◽  
Secondary Roots ◽  
Root Observation

To describe the different types of geotropic reactions of hevea (Hevea brasiliensis), young seedlings were cultivated in root observation boxes and submitted to a double gravistimulation (90° rotation of the minirhizotrons in the vertical plane). It was demonstrated that the taproot is a strongly orthogeotropie organ since it resumed rapidly its prestimulation vertical position. Morphological and morphogenetic modifications were associated with the geotropic response: reduced speed of growth coupled with a reduction of the apical diameter as well as an alteration of ramification density in the curving zone and the following one. Early secondary roots showed a somewhat reduced orthogeotropism that was weaker as the growth direction before gravistimulation was more distant from the vertical. Secondary roots of the acropetal sequence were semiplagiotropic, that is only those roots oriented upward after the gravistimulation resumed, more or less, the original direction. Tertiary roots didn't respond to the gravistimulation and therefore were ageotropic. Complementary observations conducted in large laboratory rhizotrons showed that late forming secondary roots were plagiotropic in their younger stages, thereafter loosing most of their sensitivity to gravity. Quaternary roots were ageotropic. On the basis of these data, a geotropic gradient was defined within the hevea root system, where the strongly responding taproot and late secondary roots are opposed to the weakly or nonresponding tertiary and quaternary roots. Functional significations of these differential geotropic reactions in different hevea root types are discussed. Keywords: geotropism, gravistimulation, root system, growth, development, morphogenesis, root observation box, Hevea brasiliensis. [Journal translation]

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.

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