scholarly journals The morphostructure of Oxalis incarnata bulbs

2020 ◽  
Vol 87-88 ◽  
pp. 32-38
Author(s):  
Alla Zhila ◽  
Olga Tymchenko

The morphostructure of the bulbs of Oxalis incarnata in the conditions of dormancy and the plant’s growth and development are described. The plants were grown in two irrigation modes: 1) with regular irrigation during the year, and 2) with limited irrigation in March-October and without irrigation in November-February. The bulbs were analyzed by way of consequent detaching of the scales. Investigated bulbs always had four fleshy scales, while the number of coriaceous and membranous scales varied. Coriaceous scales, together with two fleshy outer scales, make a protective envelope of the bulb.The overground shoot of O. incarnata, just like in other species of the genus, demonstrates monopodial growth and can produce up to five levels of lateral branches. Elongated parts of overground shoots serve for new territories’ useful occupation, while shortened parts produce new particles. Resting buds (bulbils) of three types were observed in O. incarnata: underground axillary buds, overground axillary gemmae, and terminal gemma. Our investigations showed polyvariance both of organogenesis of the resting buds and ontogenesis of plants in general, depending on irrigation regimes. In the case of limited irrigation, the plants of O. incarnata shed the leaves and can produce terminal gemma. While in the case of regular irrigation during the year, they remain evergreen and form gemmae exclusively in the leaves’ axils. We did not observe the formation of terminal gemmae in the case if axillary gemmae were present.The root system of O. incarnata has a complex structure. It consists of two crowns of the filamentary roots, contractile roots, and additional adventitious roots located along the underground part of the shoot during its growth. Such structure of the root system probably ensures better absorption of the water.

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Valters Samariks ◽  
Dace Brizga ◽  
Jeļena Rūba ◽  
Andris Seipulis ◽  
Āris Jansons

Climate change will cause winds to strengthen and storms to become more frequent in Northern Europe. Windstorms reduce the financial value of forests by bending, breaking, or uprooting trees, and wind-thrown trees cause additional economic losses. The resistance of trees to wind damage depends on tree species, tree- and stand-scale parameters, and root-soil plate characteristics such as root-plate size, weight, and rooting depth. The root-soil plate is a complex structure whose mechanical strength is dependent on root-plate width and depth, as the root system provides root attachment with soil and structural support. In Latvia, the common aspen (Populus tremula L.) root system has been studied to develop a belowground biomass model, because information about root system characteristics in relation to tree wind resistance is scarce. The aim of this study was to assess the root-plate dimensions of common aspen stands on fertile mineral soil (luvisol). Study material was collected in the central region of Latvia, where pure mature (41–60 years old) common aspen stands were randomly selected, and dominant trees within the stand were chosen. In total, ten sample trees from ten stands were uprooted. The diameter at breast height (DBH) and tree height (H) were measured for each sample tree, and their roots were excavated, divided into groups, washed, measured, and weighed. The highest naturally moist biomass values were observed for coarse roots, and fine root biomass was significantly lower compared to other root groups. All root group biomass values had a strong correlation with the tree DBH. The obtained results show that there is a close, negative relationship between the relative distance from the stem and the relative root-plate depth distribution.


2006 ◽  
Vol 42 (3) ◽  
pp. 351-366 ◽  
Author(s):  
J. J. COMIN ◽  
J. BARLOY ◽  
V. HALLAIRE ◽  
F. ZANETTE ◽  
P. R. M. MILLER

The aim of this work was to study the effects of soluble aluminium on the morphology and growth of the adventitious root system, aerial biomass and grain yield of maize (Zea mays). The analysis focuses on two hybrid cultivars (Al-sensitive HS7777 and Al-tolerant C525M). Experiments were carried out in the field and in a rhizotron in Curitiba, Paraná, Brazil. In the field, four levels of lime application were used: T0 = 0 t ha−1, T1 = 3.5 t ha−1, T2 = 7.0 t ha−1, and T3 = 10.5 t ha−1. Two levels were used in a rhizotron: T0 and T3. In the surface horizon (0–15 cm), the Al concentrations of the soil solution were: T0 = 15, T1 = 5.1, T2 = 4.4, and T3 = 3.1 μM. In the field, neither Al concentration in the soil solution nor cultivar affected the number of primary adventitious roots per internode or the total number of primary adventitious roots. However, root diameter, plant population and grain yield of the two cultivars confirmed the differences in Al tolerance between them. Al was observed to have an adverse effect on the grain yield from C525M, while low yields from HS7777, at all levels of Al, precluded any response to liming. In the rhizotron studies, Al concentration and cultivar affected the root branching and total root length. Cultivar C525M had more branches and total root length than HS7777, mainly at low concentrations of soil Al solution, leading to greater spatial colonization of the soil down to 0.9 m depth.


2014 ◽  
Vol 51 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Krystyna Kriesel ◽  
Sławomir Ciesielska

The investigations were performed on pine seedlings growing under 12, 16 and 20 hour photoperiods. In 4 succesive stages of seedling development i.e. after 2, 12, 18 and 30 weeks of culture morphological characters of the seedlings were measured and the levels of auxins-, gibberellins-, cytokininsand abscisic acid-like inhibitor were determined. The intensity of growth and development of juvenile leaves, needles and of the shoot was the lowest in plants growing under 12 hour photoperiod conditions. As the length of the photoperiod increased so did the intensity of these processes. Under the 12 hour photoperiod the development of scale leaves, axillary buds and the formation of the terminal bud started earliest. This process reached completion under the 12 hour photoperiod and the bud remained in a state of dormancy. Seedlings growing under the 12 hour photoperiod were characterized by a low level of stimulators, and at the same time by a high level of inhibitors. On the other hand in seedlings grown at 16 and 20 hour photoperiods the content of stimulators was higher and that of inhibitors lower. A high intensity of growth and development processes was correlated with a high level of stimulators while a high level of inhibitors was correlated with a low intensity of these processes.The obtained results suggest the participation of gibberellins and cytokinins in the processes of regulation of the initiation of scale leaves and axillary buds, and the participation of these hormones and of abscisic acid in the regulation of needle elongation.


1981 ◽  
Vol 32 (2) ◽  
pp. 257 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.


1973 ◽  
Vol 51 (7) ◽  
pp. 1373-1377 ◽  
Author(s):  
Coleman R. Robison ◽  
Christopher P. Person

A silicified dicotyledon rhizome is described from the Eocene Allenby Formation of the Princeton Coal Basin, British Columbia. The primary and secondary vascular tissues of the rhizome form a narrow cylinder around a broad, parenchymatous pith. The rhizome's salient feature is a wide cortex in which there are numerous air cavities. In most specimens the cortex is surrounded by a single layer of epidermal cells but in some there is evidence of periderm initiation. Small lateral branches are borne on the main axis, and both the main and lateral axes bear broad, clasping leaf bases and adventitious roots. The affinities of this rhizome are presently unknown, but its anatomical structure is indicative of a semiaquatic plant.


2020 ◽  
pp. 171-178
Author(s):  
Evgeniy Nikolayevich Sechin ◽  
Oleg Anatolyevich Marakaev ◽  
Gavriil Borisovich Gavrilov

For the first time, the phytosterol state of the underground and aboveground organs of the tuberoid species of the orchid Dactylorhiza maculata (L.) Soó (Orchidaceae), which grows in the natural conditions of the Central European part of Russia, was studied using gas chromatography with a mass spectrometric detector. The plant material contains cycloartenol, cycloeukalenol, campesterol, brassicasterin, β-sitosterol, stigmasterol and ergosterol, which was found in underground organs and belong to mycosymbiont. The ergosterol content in the adventitious roots is five times higher compared to the endings of stem root tuberoids. The phytosterols content of the aboveground organs of D. maculata is more diverse than that of the underground organs. The basic sterol of D. maculata is β-sitosterol (60%), which is present in all organs. Also a high amount was noted for cycloartenol (20%), which is absent in the stem. Cycloeukalenol (7%) was found in inflorescences and leaves, campesterol (2%) in inflorescences, brassicasterin (5%) in the adventitious roots, stigmasterol (5%) in the leaves. Differences in the sterol statuses of organs can be explained by the biochemical characteristics of their tissues and the uneven functional significance of the identified compounds for the growth and development of generative individuals of D. maculata in the budding phase. The results obtained indicate the diversity of phytosterol compounds and their uneven content in various organs of the studied plant object.


Author(s):  
Eduard G. Hachaturov ◽  
◽  
Valeria V. Korobko ◽  

The objects of the study were plants of 14 varieties of durum wheat Triticum durum Desf. Cultivation was carried out in a climatic chamber at a temperature of 18 ± 1°C under the conditions of a sixteen-hour photoperiod. To study the growth characteristics of the root system of seedlings, the length of the main root and the length of the adventitious roots of the upper and lower tiers were measured; thus, the growth rate of the root system was determined. The cultivars, the seedlings of which are characterized by the longest root system, have been identified – Luch 25, Saratovskaya 59 and Saratovskaya zolotistaya. The varietal characteristics of the growth of the main embryonic root were revealed, the growth rate of which significantly varies among the objects of study. The length of the adventitious roots of the lower layer in plants of the studied varieties ranged from 208 mm (Elizavetinskaya) to 278 mm (Saratovskaya 57 and Annushka); the upper layer – from 105 mm (Nikolasha) to 216 mm (Luch 25). The root-to-shoot ratio was calculated. In 5-day-old seedlings of the studied varieties, this varies from 0,92 to 1,89 rel. units; the degree of variation of the trait is average. In 12-day-old seedlings, the root supply index decreases, amounting to 0,42–1,29 relative units; the degree of variation of the trait is significant (with the exception of variety Luch 25).


2012 ◽  
Vol 62 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Anna K. Sawilska ◽  
Ewa Jendrzejczak ◽  
Monika Welc ◽  
Barbara Kieliszewska-Rokicka

The significance of root colonization by mycorrhizal fungi for the growth and development of <i>Helichrysum arenarium</i> was investigated in two independent experiments. In the first experiment the association of root colonization level with the pluviothermal conditions within the growing season and the age of a natural plant population was analyzed. In the second one, under controlled conditions, the influence of artificial inoculation with the arbuscular fungus <i>Glomus intraradices</i> on the features of plants raised from achenes was studied. It was shown that hydrothermal conditions during blooming period had a greater influence on reproduction processes of sandy everlasting than both the population age (the secondary succession progress) and the level of root colonization by mycorrhizal fungi. High amount of precipitation at plant generative development phase positively influences the potential and actual fertility of ramets. The presence of arbuscular fungus in the soil favors the growth and development of sandy everlasting specimens at their early growing stages: they have a better-developed root system and a greater photosynthetic area.


2019 ◽  
Vol 168 (1) ◽  
pp. 227-236
Author(s):  
Corinne Agapit ◽  
Agnès Gigon ◽  
Thomas Girin ◽  
Luis Leitao ◽  
Manuel Blouin

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