The morphology and anatomy of proteoid roots in the genus Hakea

1972 ◽  
Vol 20 (2) ◽  
pp. 155 ◽  
Author(s):  
B Lamont
Keyword(s):  
Special Reference ◽  
Root System ◽  
Plant Age ◽  
Proteoid Roots ◽  
Relative Contribution ◽  
Endophytic Microorganisms ◽  
As Species ◽  
The Family ◽  
Proteoid Root

This paper extends the introductory work of Purnell(1960) on proteoid roots in the family Proteaceae by a detailed study of the genus Hakea, with special reference to H. prostrata. The presence of proteoid roots is reported in 63 Hakea species. Their relative contribution to the root system is related to such plant factors as species, age, and cotyledon size. The dimensions of proteoid roots are dependent on plant age and species. The morphology and anatomy of these structures are described. Endophytic microorganisms are not normally associated with proteoid roots. Proteoid rootlets survive 2-3 months, though their parent roots last indefinitely. Proteoid roots are produced by the youngest roots in the root system. While proteoid rootlets arise laterally, the parent root may arise either laterally or adventitiously. Both proteoid and non-proteoid roots may be initiated within a proteoid root.

The Effects of Seasonality and Waterlogging on the Root Systems of a Number of Hakea Species

1976 ◽  
Vol 24 (6) ◽  
pp. 691 ◽  
Author(s):  
B Lamont
Keyword(s):  
Redox Potential ◽  
Root System ◽  
Water Availability ◽  
Field Capacity ◽  
Climatic Conditions ◽  
Root Weight ◽  
Proteoid Roots ◽  
Growth Increase ◽  
Steep Decline ◽  
Proteoid Root

Proteoid and non-proteoid roots are produced only during winter-spring under the Mediterranean climatic conditions of south-western Australia. However, dormant roots can be induced to form new root structures in summer, if sufficient water is applied to that part of the root system. The seasonal occurrence of proteoid roots is therefore due to the annual variation in water available for growth of the surface parent roots. Both proteoid and non-proteoid root growth increase as water availability is increased from the permanent wilting point to one to two times field capacity, with a trebling in the proportion of proteoid roots by weight in the root system. This is followed by a steep decline in total root weight and in the proportion of proteoid roots in the root system as water availability is increased from two to three times field capacity. While the size of proteoid roots is greatest under non-waterlogged conditions (redox potential of 450-550 mV), their number per unit total root weight is greatest under moderately waterlogged conditions (redox potential of 120-350 mV).

Factors affecting the distribution of proteoid roots within the root systems of two Hakea species

1973 ◽  
Vol 21 (2) ◽  
pp. 165 ◽  
Author(s):  
B Lamont
Keyword(s):  
Organic Matter ◽  
Root System ◽  
Root Systems ◽  
Physical Factors ◽  
Root Weight ◽  
Local Concentration ◽  
Horizontal Distance ◽  
Proteoid Roots ◽  
Local Soil ◽  
Proteoid Root

The proteoid roots of Hakea prostrata and H. laurina are concentrated in the surface soil horizons, even though the root systems penetrate to much greater depths. The relationships of a number of soil and plant factors to proteoid root occurrence in a given portion of the root system were examined. Pockets of humus-rich soil in any part of the root system greatly increased the proteoid root concentration in that region. The following factors, listed in their apparent order of importance, were analysed: local concentration of parent roots, local level of soil organic matter, local nitrogen availability, shoot growth, nitrogen concentration of the shoots, vertical distance of the region from the soil surface, local availability of calcium, magnesium, and potassium, local bulk density and certain other physical factors, nutrient status of the rest of the root system, horizontal distance of the region from the centre of the plant, relative maturity of parent roots in the region, and local soil pH and certain other chemical factors. The nitrogen component of soil regions high in organic matter largely accounted for their higher non-proteoid root concentration, smaller proteoid root size, greater number of laterals, and longer roots per unit weight, but not their much greater number of proteoid roots per unit total root weight. This suggests that other factors are also involved in proteoid root formation.

The Effect of Soil Nutrients on the Production of Proteoid Roots by Hakea Species

1972 ◽  
Vol 20 (1) ◽  
pp. 27 ◽  
Author(s):  
B Lamont
Keyword(s):  
Root Growth ◽  
Response Curve ◽  
Nitrogen Availability ◽  
Root Production ◽  
Proteoid Roots ◽  
Relative Contribution ◽  
Root Response ◽  
Proteoid Root ◽  
Two Phases ◽  
The Relationship

The mode of the proteoid root response curve occurs at a considerably lower level of nitrogen or phosphorus than that of the response curve for non-proteoid roots. As a consequence, the relationship between proteoid and non-proteoid roots can be regarded as passing through four phases as nutrient availability increases: (a) an increase in proteoid root production as non-proteoid root growth increases; (b) a decrease in proteoid root production as non-proteoid root growth increases; (c) a decrease in proteoid root production as non-proteoid root growth decreases; (d) an absence of proteoid roots as non-proteoid root growth decreases. Only the first two phases are considered relevant to plants growing under field conditions. It is concluded that nutrient concentration in a number of soils, especially nitrogen availability, largely determines the relative contribution of proteoid roots to the root systems of two species of Hakea.

Distribution and density of the root system of macadamia on krasnozem soil and some effects of legume groundcovers on fibrous root density

2003 ◽  
Vol 43 (5) ◽  
pp. 503 ◽  
Author(s):  
D. J. Firth ◽  
R. D. B. Whalley ◽  
G. G. Johns
Keyword(s):  
Root System ◽  
Root Length ◽  
Root Length Density ◽  
Root Systems ◽  
Soil Cores ◽  
Fibrous Root ◽  
Proteoid Roots ◽  
Dry Conditions ◽  
Proteoid Root ◽  
Fibrous Roots

Whole-tree excavations, root-core and minirhizotron studies indicate that the grafted macadamia tree root system is relatively shallow and spreading, with a short taproot and most of the fibrous root system near the soil surface, while ungrafted trees have a longer taproot. The length of fibrous roots diminished with depth and distance from the trunk. This pattern is consistent with other fruit trees, in that the highest density is generally within 1 m of the trunk. Values obtained in core samples in this study were 4.97 (± 0.43) cm/cm3 and 1.67 (± 0.45) cm/cm3 for 0–10 cm and 10–20 cm at 0.5 m from the trunk, and 2.34 and 1.08 cm/cm3, respectively, at 1 m from the trunk at Clunes. These values were similar to those obtained in separate studies in 1991–93, involving assessments at 5�cm depth increments down to 15 cm, where mean root length densities were 2.0–3.5 cm/cm3 and 1.3–1.9 cm/cm3 at 0–5 cm and 5–15 cm depth, respectively, 1.4 m from the trunk. Root length under old trees in bare soil at Dorroughby and Clunes, using minirhizotrons (0.25–0.40 cm/cm2) and soil cores (1.14 and 3.50 cm/cm3, respectively), was similar to that found at other sites in the study area (minirhizotrons 0.28–0.33 cm/cm2; soil cores 1.25–2.80 cm/cm3). There is an apparent lower rate of decrease in root length density with increasing distance from the trunk at 10–20 cm compared with 0–10 cm. New root growth occurred predominantly in autumn, but some new fibrous roots were produced in early winter and spring. Proteoid roots were found in abundance in soil cores and adjacent to minirhizotron tubes and there were more of them in the root systems of younger trees at Clunes than with older trees at Dorroughby. Proteoid roots were found at a greater depth than previously recorded for other Proteaceae species, and appeared to retain their function in relatively dry conditions for more than a year. Non-proteoid fibrous roots at the minirhizotron surface appeared to be functional for about 1.5 years in relatively dry conditions, before decay after the onset of wet soil conditions.The effects of 2 newly established perennial legume groundcovers on the root systems of younger and older macadamia trees were studied over 2.5 years. In general, the presence of groundcover either had no effect on the growth of the macadamia roots or increased the root length density at some sampling dates and some depths. At Clunes, where the proteoid root length density was higher than at Dorroughby, the presence of groundcover was associated with higher proteoid root length density than that with bare ground. Arachis pintoi cv. Amarillo generally had a lower root length density than Lotus pedunculatus.

Studies of the family Proteaceae. I. Anatomy and morphology of the roots of some Victorian species

1960 ◽  
Vol 8 (1) ◽  
pp. 38 ◽  
Author(s):  
HM Purnell
Keyword(s):  
Root System ◽  
Primary Root ◽  
Secondary Growth ◽  
Anatomical Features ◽  
The Family ◽  
Proteoid Root

The term ''proteoid root" is defined. The morphological and anatomical features of such roots are described. A shorn account is given of the anatomy of the primary root and of roots in which secondary growth has occurred. The types of root system found among representative Victorian genera are also described.

Comments on “Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species” by Coimbra, Bergue & Ramos (2020)

Zootaxa ◽  
2021 ◽  
Vol 4950 (2) ◽  
pp. 398-400
Author(s):  
OKAN KÜLKÖYLÜOĞLU
Keyword(s):  
New Species ◽  
Integrated Approach ◽  
Taxonomic Position ◽  
New Family ◽  
As Species ◽  
Diagnostic Characteristics ◽  
The Family ◽  
Two New Species

Most recently, Coimbra et al. (2020) published an article in this journal (Zootaxa, 4729 (2): 177–194) questioning the taxonomic position of the genus Copytus Skogsberg, 1939 (Crustacea, Ostracoda) along with proposing it as the type genus of their new family (Copytidae Coimbra et al., 2020), and erecting two new species that were listed by previous authors as Copytus sp. 1 and Copytus sp. 2. The main diagnostic characteristics of their new proposed family (and the genus Copytus) are the hinge type and muscle scars on the carapace and/or valves (see lines 6–8 from the bottom, p. 179 in Coimbra et al. 2020). They also underlined that (p. 179) “...this study is based exclusively on the morphology of the animals’ hard parts”. While the authors considered another genus (Neocopytus) proposed by Külköylüoğlu, Colin & Kılıç (2007) of the family Neocytherididae as invalid, they interestingly transferred some species of Neocopytus to Copytus as species of their new family (Coimbra et al. 2020). Herein, my point with the comments listed below is to clarify that, when possible, both soft and hard parts should be considered in taxonomy, and such an integrated approach clearly indicates that Neocopytus is a valid and taxonomically useful genus. 

scholarly journals GENOME SIZE DETERMINATION OF CUCUMBER (CUCUMIS SATIVUS), HONEYDEW (CUCUMIS MELO INODORUS) AND ROCK MELON (CUCUMIS MELO CANTALUPENSIS) VIA FLOW CYTOMETRY

2021 ◽  
Vol 5 (1) ◽  
pp. 14-16
Author(s):  
Raden Muhamad Imaduddin Yumni ◽  
Mohd Fauzihan Karim ◽  
Mohd Razik Midin
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Cucumis Melo ◽  
As Species ◽  
External Reference ◽  
The Family ◽  
Cucumis Species ◽  
Fcm Analysis ◽  
Interspecific And Intraspecific Variation

The family of Cucurbitaceae consists of species with economical and nutritional value. Morphologically, there are only few differences between Cucumis species. The interspecific and intraspecific variation in the genome size of the Cucumis species are not discovered yet. Due to this, this study aims to determine the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis using flow cytometry (FCM) method. Nuclei suspension of selected Cucumis species were extracted using LBO1 lysis buffer by manual chopping technique and stained by propidium iodide priot to FCM analysis. Genome size of C. sativus, C. melo inodorus (Honeydew) and C. melo cantalupensis (Rockmelon) were determined by using Glycine max (Soybean) as an external reference standard (2C = 2.5 pg). This study found that the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis estimated to be 2.83 pg, 3.00 pg and 3.47 pg respectively. The genome size data obtained from this study can be used in future genome studies as well as species characterization.

The taxonomy of the order Isochrysidales (Prymnesiophyceae) with special reference to the genera Isochrysis Parke, Dicrateria Parke and Imantonia Reynolds

1977 ◽  
Vol 57 (1) ◽  
pp. 7-17 ◽  
Author(s):  
J. C. Green ◽  
R. N. Pienaar
Keyword(s):  
Special Reference ◽  
New Class ◽  
The Third ◽  
Unique Structure ◽  
The Family ◽  
Unique Status

The order Isochrysidales was erected by Pascher in 1910 to accommodate chrysomonads with two equal flagella. It was based on the family Hymenomonadaceae (Senn, 1900) and included such genera as Synura Ehrenberg (later shown to be heterokont and therefore incorrectly placed here; Hovasse, 1949; Manton, 1955), Wyssotzkia Lemmermann and Hymenomonas Stein. Papenfuss (1955) used the name in a similar sense but encompassing also the coccolithophorids, while those genera with two equal flagella and a ‘short third flagellum’ ((Prymnesium Massart, Platychrysis N. Carter, Chrysochromulina Lackey) were placed in the order Prymnesiales. Subsequently it was demonstrated that members of the Isochrysidales and Prymnesiales differ from other chrysomonads in that the two true flag-ella are smooth with no coarse hairs (‘mastigonemes’) and that the third appendage found in genera of the latter order is a unique structure, termed the ‘haptonema’ by Parke, Manton & Clarke (1955). On the basis of these observations, Christensen (1962) erected a new class, the Haptophyceae (now referred to by the typified name Prymnesiophyceae; Hibberd, 1976 a), to contain the two orders although Bourrelly (1968) preferred to retain them within the Chrysophyceae whilst recognizing their unique status by the erection of a sub-class, the Isochrysophycidae.

Charles Spence Bate: what’s in a name?

Zootaxa ◽  
2018 ◽  
Vol 4497 (3) ◽  
pp. 429 ◽  
Author(s):  
PAUL F. CLARK
Keyword(s):  
Special Reference ◽  
Manual Search ◽  
Overwhelming Evidence ◽  
The Family

The citation of Charles Spence Bate has become a source of uncertainly in the literature. Indeed, for some taxa his authority is given as “Spence Bate”, whilst others “Bate” e.g. Artemesia longinaris Spence Bate, 1888 compared with Ibacus brevipes Bate, 1888. In order to resolve this inconsistency, a lengthy manual search of selected contemporary journals for the period from ca. 1854 to 1889 was undertaken with special reference to the name Charles Spence Bate being listed alphabetically by family/surname either under “Bate”, “Spence Bate” or “Spence-Bate”. Overwhelming evidence indicated that his family/surname is Bate. Furthermore, as there are a number of carcinologists also with the family name Bate, therefore it is recommended that taxa described by Charles Spence Bate should be referred to as C.S. Bate, for example Artemesia longinaris C.S. Bate, 1888 and Ibacus brevipes C.S. Bate, 1888. 

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