Regenerative studies on the detached leaves of Echeveria elegans. Anatomy and regeneration of leaves in sterile culture

1970 ◽  
Vol 48 (10) ◽  
pp. 1887-1891 ◽  
Author(s):  
M. V. S. Raju ◽  
Henry E. Mann
Keyword(s):  
Vascular Tissue ◽  
Agar Medium ◽  
Vascular Differentiation ◽  
Leaf Base ◽  
Adaxial Side ◽  
Regenerative Capacity ◽  
Abaxial Side ◽  
Sterile Culture ◽  
Detached Leaves ◽  
Young Leaves

Excised leaves, L1–L30, of Echeveria elegans Bgr. were cultured aseptically on an agar medium to study their regenerative capacity. The younger leaves tended to produce roots earlier than shoots and some had not produced shoots by the time of termination of the experiments. The older leaves produced shoots earlier than roots and in such instances the shoots appeared on the adaxial side. In no case was the appearance of shoots on the abaxial side of the leaf noticed and this suggested the possible manifestation of polarity of regeneration. The leaf regeneration to produce roots or shoots depended on the degree of vascular differentiation, particularly at the leaf base where regeneration normally occurs. In young leaves that had little or no vascular differentiation at the time of their isolation, abundant callus appeared in which the first primordia initiated were of roots. The old detached leaves had short petioles, which contained mature vascular tissue, and produced very little callus in culture.

Regenerative studies on the detached leaves of Echeveria elegans. Patterns of regeneration of leaves in sterile culture

1971 ◽  
Vol 49 (11) ◽  
pp. 2015-2021 ◽  
Author(s):  
M. V. S. Raju ◽  
Henry E. Mann
Keyword(s):  
Agar Medium ◽  
Shoot Formation ◽  
Proximal Region ◽  
Leaf Base ◽  
Regeneration Potential ◽  
Inverted Position ◽  
Sterile Culture ◽  
Regeneration Pattern ◽  
Detached Leaf ◽  
Detached Leaves

Entire detached leaves (L30 and older) and leaf-halves of Echeveria elegans Bgr. were cultured aseptically on an agar medium to study their regenerative capacity. The entire leaves with their bases intact produced shoots and roots regardless of whether they were placed erect, inverted, or flat on the medium. Similar leaves with their bases severed and placed erect produced roots from their cut ends. The proximal leaf-halves showed a regeneration pattern similar to the entire leaves depending on, of course, whether the leaf bases were cut or not. The regeneration in the distal halves was identical to the proximal halves whose bases had been removed. In the inverted position, a few distal halves and proximal halves with their bases removed produced shoots and roots. In all leaf types, inverted, erect, or flat, the regeneration occurred at the proximal end and in some exceptional cases, roots were formed at the distal cut end too. In general, the regeneration potential appeared to be much greater in the proximal parts than in the distal parts of detached leaves and the anatomy in the former was more favorable for regeneration than in the latter. Cutting the leaf base altered the regeneration pattern in the detached leaf but it did not have any effect on the capacity for regeneration to produce differentiated organs. The leaf fragments showed strict polarity in shoot formation which occurred only in the proximal region. The roots, on the other hand, appeared at proximal and distal ends.

Regulation of vascular differentiation in leaf primordia during the rhythmic growth of Gnetum africanum

1986 ◽  
Vol 64 (1) ◽  
pp. 208-213 ◽  
Author(s):  
F. Mialoundama ◽  
P. Paulet
Keyword(s):  
Principal Axis ◽  
Vascular Tissue ◽  
Growth Period ◽  
Leaf Primordia ◽  
Single Pair ◽  
Vascular Bundles ◽  
Vascular Differentiation ◽  
Terminal Bud ◽  
Young Leaves ◽  
Rhythmic Growth

The growth of the principal axis of Gnetum africanum Welw. is achieved by successive growth and rest periods. During the phase of growth arrest, the terminal bud produces a single pair of leaf primordia containing no vascular tissue whereas observation of the terminal bud of the vinelike stem reveals that the oldest of the leaf primordia do contain vascular tissue before emerging. The differentiation of vascular bundles in the leaf primordia of the principal axis begins only with the return of the growth period during which time new young leaves are formed. The rhythm of formation of the leaves and their vascularization can be accelerated by removal of the young leaves. A prolonged exogenous treatment with abscisic acid after removal of the young leaves reestablishes the inhibition and prevents initiation of vascularization. It seems, therefore, that in the principal axis young leaves inhibit vascular differentiation of the leaf primordia, which may partly explain the inhibition of growth.

scholarly journals Oviposition by the vagrant eriophyoid mite Aculops allotrichus on leaves of black locust tree, Robinia pseudoacacia

2019 ◽  
Vol 79 (1) ◽  
pp. 1-19
Author(s):  
Katarzyna Michalska ◽  
Anna Tomczyk ◽  
Barbara Łotocka ◽  
Sławomir Orzechowski ◽  
Marcin Studnicki
Keyword(s):  
Cell Walls ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Leaf Age ◽  
Leaf Tissue ◽  
Adaxial Side ◽  
Abaxial Side ◽  
Production And Distribution ◽  
Young Leaves ◽  
Eriophyoid Mite

Abstract Leaf-dwelling mites often prefer to feed on young leaves and also are more likely to inhabit the abaxial leaf side. The aim of our study was to examine whether leaf age may affect production and distribution of eggs on black locust leaves by females of Aculops allotrichus. The eriophyoids were tested for 2.5 days on ‘trimmed’ compound leaves (with only two opposite leaflets left), which were maintained in vials filled with water. For the experiments we used leaves of three categories: (1) the ‘youngest’, in which both halves of the adaxial side of leaflets still adhered to each other (and usually remained folded for the next few hours), (2) ‘young’ with already unfolded leaflets, and (3) ‘mature’ with fully expanded leaflets. The tested females laid significantly more eggs on developing leaves than on ‘mature’ ones, although they deposited the highest number of eggs on the ‘young’ leaves. The distribution of eggs on adaxial or abaxial leaf sides also depended on leaf age. On the ‘youngest’ leaves, eriophyoids placed similar numbers of eggs on both sides of a blade. However, the older the leaf, the more willingly females deposited eggs on the abaxial side. Our biochemical and morphometrical analyses of black locust leaves indicated significant changes in the contents of nutrients and phenols within leaf tissue, and in the density of trichomes and thickness of the outer epidermal cell walls, correlated with leaf age. Their possible effects on the production and distribution of eggs on leaves by A. allotrichus are discussed.

scholarly journals Photosynthetic Characteristics of Individual Strawberry (Fragaria ×ananassa Duch.) Leaves under Short-distance Lightning with Blue, Green, and Red LED Lights

HortScience ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 452-458 ◽  
Author(s):  
Yuya Mochizuki ◽  
Saori Sekiguchi ◽  
Naomi Horiuchi ◽  
Thanda Aung ◽  
Isao Ogiwara
Keyword(s):  
Short Distance ◽  
Red Light ◽  
Response Curves ◽  
Adaxial Side ◽  
Abaxial Side ◽  
Mature Leaves ◽  
Red Led ◽  
Young Leaves ◽  
Red Leds ◽  
Green Leds

To clarify the response of net photosynthetic rate (Pn), stomatal conductance (gS), transpiration rate (Tr), and leaf intercellular CO2 concentration (Ci) to irradiance on the adaxial and abaxial sides of mature and young strawberry leaves using blue, green, and red light-emitting diodes (LEDs), irradiation from a short distance was investigated using ‘Tochiotome’. Light–photosynthetic response curves of the adaxial side of mature leaves were not different among LED treatments. However, those of the adaxial side of young leaves irradiated with red LEDs were less than those of other LED treatments. Pn of the abaxial side of mature leaves was 42% to 71% of the abaxial side. In young leaves, Pn of the abaxial side was 17% to 68% of the adaxial side. Moreover, light–transpiration response curves were different with LED treatments. Ci and Tr under blue and green LEDs were greater than those under red LEDs. This indicates that blue and green lights affected the stomatal opening. In contrast, red LEDs decreased Ci more than other LED treatments. In addition, reactions of the adaxial side of young leaves under blue and red LEDs were seen not only in ‘Tochiotome’, but also in ‘Sachinoka’ and ‘Eran’, which indicates that the photosynthetic reactions of blue light and red light are common characteristics of the strawberry. Therefore, red LEDs promoted the photochemical reaction and activated the CO2 fixation system. Based on the results of this study of short-distance lighting with LEDs in strawberry production, irradiance of the abaxial side of leaves by blue or green LEDs might improve more assimilates in young leaves compared with red LEDs to increase strawberry yield.

Surface and Internalized Escherichia coli O157:H7 on Field-Grown Spinach and Lettuce Treated with Spray-Contaminated Irrigation Water

2010 ◽  
Vol 73 (6) ◽  
pp. 1023-1029 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
CATHY C. WEBB ◽  
JUAN CARLOS DIAZ-PEREZ ◽  
SHARAD C. PHATAK ◽  
JOHN J. SILVOY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Irrigation Water ◽  
Enrichment Culture ◽  
Field Studies ◽  
Plate Count ◽  
Escherichia Coli O157 ◽  
Adaxial Side ◽  
Abaxial Side ◽  
E Coli ◽  
Contaminated Irrigation Water

Numerous field studies have revealed that irrigation water can contaminate the surface of plants; however, the occurrence of pathogen internalization is unclear. This study was conducted to determine the sites of Escherichia coli O157:H7 contamination and its survival when the bacteria were applied through spray irrigation water to either field-grown spinach or lettuce. To differentiate internalized and surface populations, leaves were treated with a surface disinfectant wash before the tissue was ground for analysis of E. coli O157:H7 by direct plate count or enrichment culture. Irrigation water containing E. coli O157:H7 at 102, 104, or 106 CFU/ml was applied to spinach 48 and 69 days after transplantation of seedlings into fields. E. coli O157:H7 was initially detected after application on the surface of plants dosed at 104 CFU/ml (4 of 20 samples) and both on the surface (17 of 20 samples) and internally (5 of 20 samples) of plants dosed at 106 CFU/ml. Seven days postspraying, all spinach leaves tested negative for surface or internal contamination. In a subsequent study, irrigation water containing E. coli O157:H7 at 108 CFU/ml was sprayed onto either the abaxial (lower) or adaxial (upper) side of leaves of field-grown lettuce under sunny or shaded conditions. E. coli O157:H7 was detectable on the leaf surface 27 days postspraying, but survival was higher on leaves sprayed on the abaxial side than on leaves sprayed on the adaxial side. Internalization of E. coli O157:H7 into lettuce leaves also occurred with greater persistence in leaves sprayed on the abaxial side (up to 14 days) than in leaves sprayed on the adaxial side (2 days).

Lack of Internalization of Escherichia coli O157:H7 in Lettuce (Lactuca sativa L.) after Leaf Surface and Soil Inoculation

2009 ◽  
Vol 72 (10) ◽  
pp. 2028-2037 ◽  
Author(s):  
GUODONG ZHANG ◽  
LI MA ◽  
LARRY R. BEUCHAT ◽  
MARILYN C. ERICKSON ◽  
VANESSA H. PHELAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Leaf Surface ◽  
Escherichia Coli O157 ◽  
Adaxial Side ◽  
Abaxial Side ◽  
E Coli ◽  
Lactuca Sativa L ◽  
Leaf Surfaces ◽  
Leaves And Roots ◽  
Leaf Lettuce

Survival and internalization characteristics of Escherichia coli O157:H7 in iceberg, romaine, and leaf lettuce after inoculation of leaf surfaces and soil were determined. A five-strain mixture of E. coli O157:H7 in water and cow manure extract was used as an inoculum for abaxial and adaxial sides of leaves at populations of 6 to 7 log and 4 log CFU per plant. The five strains were individually inoculated into soil at populations of 3 and 6 log CFU/g. Soil, leaves, and roots were analyzed for the presence and population of E. coli O157:H7. Ten (4.7%) of 212 samples of leaves inoculated on the adaxial side were positive for E. coli O157:H7, whereas 38 (17.9%) of 212 samples inoculated on the abaxial side were positive. E. coli O157:H7 survived for at least 25 days on leaf surfaces, with survival greater on the abaxial side of the leaves than on the adaxial side. All 212 rhizosphere samples and 424 surface-sanitized leaf and root samples from plants with inoculated leaves were negative for E. coli O157:H7, regardless of plant age at the time of inoculation or the location on the leaf receiving the inoculum. The pathogen survived in soil for at least 60 days. Five hundred ninety-eight (99.7%) of 600 surface-sanitized leaf and root samples from plants grown in inoculated soil were negative for E. coli O157:H7. Internalization of E. coli O157:H7 in lettuce leaves and roots did not occur, regardless of the type of lettuce, age of plants, or strain of E. coli O157:H7.

scholarly journals ISOLATION OF ANTIFUNGI BACTERIA FROM BANANA RHIZOSPHERE TO INHIBIT Fusarium Oxysproum f.sp cubense (FOC) GROWTH

2019 ◽  
Vol 5 (3) ◽  
pp. 105
Author(s):  
Albert Sembiring ◽  
Natalia Lusianingsih Sumanto
Keyword(s):  
Fungal Pathogen ◽  
Room Temperature ◽  
Biocontrol Agent ◽  
Vascular Tissue ◽  
Agar Medium ◽  
Wilt Disease ◽  
In Vitro Test ◽  
Panama Disease ◽  
Vitro Test

Fusarium wilt disease on banana has been known as panama disease one of the main diseases that cause huge losses for banana farmers. It is caused by the soil-borne fungal pathogen, Fusarium oxysporum f.sp cubense (Foc), which is very hard control because it is saprophytic in the soil. The mold infiltrates the root to vascular tissue that induces yellowing on the leaf, so this pathogen can attack the root, stem dan leaf. The research aimed to search bacteria from the banana rhizosphere that have an antifungal activity to inhibit Foc growth. Bacteria was isolated by serial dilution then was spread on King’s B agar medium incubation 28oC (room temperature). Four quadrants in vitro test on PDA medium used twenty bacterial from isolation, from the test was obtained six isolates have the potential to inhibit the growth of Foc. Based on percentage inhibition radial growth four isolates that have inhibition 50% over which TR2 was the highest at 79.07%. The in vitro test confirmed that bacteria from the banana rhizosphere have potential as biocontrol agent because it was able to inhibit the Foc growth.

Two New Species of Lauraceae from Ecuador

Phytotaxa ◽  
2018 ◽  
Vol 346 (2) ◽  
pp. 180 ◽  
Author(s):  
WALTER A. PALACIOS
Keyword(s):  
New Species ◽  
Leaf Base ◽  
Two New Species ◽  
Young Leaves

Two species of Lauraceae of Ecuador are described: Aniba magnifica and Ocotea granulosa. Aniba magnifica is characterized by its large vegetative parts and its dense strigulose indumentum on the underside of its young leaves, inflorescences and bracts. Ocotea granulosa is distinguishable by the dense strigulose indumentum, mixed with amorphous blackish granules on the underside of the young leaves, peduncles, pedicels and receptacles, and by a flat or slightly recurved leaf base.

SUPERMAN attenuates positive INNER NO OUTER autoregulation to maintain polar development of Arabidopsis ovule outer integuments

Development ◽  
2002 ◽  
Vol 129 (18) ◽  
pp. 4281-4289
Author(s):  
Robert J. Meister ◽  
Louren M. Kotow ◽  
Charles S. Gasser
Keyword(s):  
De Novo ◽  
Outer Integument ◽  
Negative Regulator ◽  
Sufficient Information ◽  
Coding Region ◽  
Adaxial Side ◽  
Abaxial Side ◽  
Protein Coding ◽  
Plant Parts ◽  
Reporter Gene Analysis

The outer integument of Arabidopsis ovules exhibits marked polarity in its development, growing extensively from the abaxial side, but only to a very limited extent from the adaxial side of the ovule. Mutations in two genes affect this asymmetric growth. In strong inner no outer (ino) mutants outer integument growth is eliminated, whereas in superman (sup) mutants integument growth on the adaxial side is nearly equal to wild-type growth on the abaxial side. Through complementation and reporter gene analysis, a region of INO 5′-flanking sequences was identified that contains sufficient information for appropriate expression of INO. Using this INO promoter (P-INO) we show that INO acts as a positive regulator of transcription from P-INO, but is not sufficient for de novo initiation of transcription in other plant parts. Protein fusions demonstrate nuclear localization of INO, consistent with a proposed role as a transcription factor for this member of the YABBY protein family. Through its ability to inhibit expression of the endogenous INO gene and transgenes driven by P-INO, SUP is shown to be a negative regulator of INO transcription. Substitution of another YABBY protein coding region (CRABS CLAW) for INO overcomes this negative regulation, indicating that SUP suppresses INO transcription through attenuation of the INO positive autoregulatory loop.

Leaf micromorphology of the Persicaria sect. Cephalophilon (Polygonaceae) and its systematic re-evaluation

Phytotaxa ◽  
2019 ◽  
Vol 391 (3) ◽  
pp. 167 ◽  
Author(s):  
MIN-JUNG KONG ◽  
SUK-PYO HONG
Keyword(s):  
Comparative Study ◽  
Cell Walls ◽  
Smooth Surface ◽  
Glandular Trichomes ◽  
Adaxial Side ◽  
Abaxial Side ◽  
Stomatal Size ◽  
Systematic Significance ◽  
Leaf Micromorphology ◽  
Anomocytic Stomata

A comparative study of the leaf microstructures of 19 taxa belonging to the Persicaria sect. Cephalophilon and related four Koenigia taxa was performed by LM and SEM to evaluate their systematic significance. Both amphistomatic and hypostomatic leaves were observed in the taxa studied. The stomatal size ranged from 17.04–41.96 × 13.41–37.30 μm, and stomata on the adaxial side were larger than those on the abaxial side in general. Anomocytic stomata occurred most commonly, but more than one type of stomata was observed on the same surface. Paracytic stomata was found in both Persicaria palmata and P. criopolitana. The epidermal cells usually have straight to sinuate anticlinal cell walls (ACW), and the ACW on the abaxial side of most taxa is much more undulated than that on the adaxial side. Cuticular striation was observed in most of the studied taxa, which was restricted to only the adaxial side. Two types of crystals were observed: druse and prismatic, and seven types of trichome were recognized: five types of non-glandular trichomes (stellate with smooth surface, multiseriate with either smooth or striated surface, and uniseriate with either smooth or papillose surface), and two types of glandular trichomes (peltate and long-stalked pilate). The leaf micromorphology in this study was categorized into five types based on the stomata, epidermis, crystal and trichome, as further systematic significance of the leaf epidermal characters within the P. sect. Cephalophilon are discussed. In addition, we propose a new taxonomic combination in the P. sect. Cephalophilon.

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