Development of a micropropagation protocol for Malus orientalis using axillary buds

2019 ◽  
Vol 55 (5) ◽  
pp. 625-634
Author(s):  
Narjes Amirchakhmaghi ◽  
Batool Hosseinpour ◽  
Hamed Yousefzadeh
Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 77
Author(s):  
Elena O. Vidyagina ◽  
Nikolay N. Kharchenko ◽  
Konstantin A. Shestibratov

Axillary buds of in vitro microshoots were successfully frozen at –196 °C by the one-step freezing method using the protective vitrification solution 2 (PVS2). Microshoots were taken from 11 transgenic lines and three wild type lines. Influence of different explant pretreatments were analyzed from the point of their influence towards recovery after cryopreservation. It was found out that the use of axillary buds as explants after removal of the apical one increases recovery on average by 8%. The cultivation on growth medium of higher density insignificantly raises the regenerants survival rate. Pretreatment of the osmotic fluid (OF) shows the greatest influence on the survival rate. It leads to the increase in survival rate by 20%. The cryopreservation technology providing regenerants average survival rate of 83% was developed. It was based on the experimental results obtained with explant pretreatment. Incubation time in liquid nitrogen did not affect the explants survival rate after thawing. After six months cryostorage of samples their genetic variability was analyzed. Six variable simple sequence repeat (SSR) loci were used to analyze genotype variability after the freezing-thawing procedure. The microsatellite analysis showed the genetic status identity of plants after cryopreservation and of the original genotypes. The presence of the recombinant gene in the transgenic lines after cryostorage were confirmed so as the interclonal variation in the growth rate under greenhouse conditions. The developed technique is recommended for long-term storage of various breeding and genetically modified lines of aspen plants, as it provides a high percentage of explants survival with no changes in genotype.


Experiments were recently reported showing that, in young seedlings of Pisum sativum , the complete inhibiting effect which the shoot exerts upon its axillary buds comes entirely or almost entirely from three or four of its developing leave acting together (6). A single developing leaf was found usually to inhibit only partially—that is to say, sufficiently to delay the growth of an axillary bud below it, but not to check it completely. The strength of this partial inhibiting effect was measured by the retardation of the outgrowth of the axillary buds of the first or lowest leaf, as compared with their growth in completely defoliated controls. Comparisons were further made of the inhibiting effects of single young leaves of equal sizes near the apex in seedlings of different ages and heights, and it was found that in very young short seedlings the inhibiting effect was very slight or inappreciable, although in seedlings of a height of about 30 mm. or more (but still possessing well filled cotyledons) the effect was strong.


Phytotaxa ◽  
2015 ◽  
Vol 219 (2) ◽  
pp. 174
Author(s):  
Fabiana Firetti Leggieri ◽  
DIEGO DEMARCO ◽  
LÚCIA G. LOHMANN

The Atlantic Forest of Brazil includes one of the highest species diversity and endemism in the planet, representing a priority for biodiversity conservation. A new species of Anemopaegma from the Atlantic Forest of Brazil is here described, illustrated and compared to its closest relatives. Anemopaegma nebulosum Firetti-Leggieri & L.G. Lohmann has been traditionally treated as a morph of Anemopaegma prostratum; however, additional morphological and anatomical studies indicated that A. nebulosum differs significantly from A. prostratum and is best treated as a separate species. More specifically, A. nebulosum is characterized by elliptic and coriaceous leaflets (vs. ovate to orbicular and membranaceous in A. prostratum), smaller leaflet blades (3.6–5.5 x 2.0–3.0 cm vs. 6.7–13.0 x 4.2–8.4 cm in A. prostratum), orbicular prophylls of the axillary buds (vs. no prophylls in A. prostratum), solitary flowers (vs. multi-flowered axillary racemes in A. prostratum) and a gibbous corolla (vs. infundibuliform corollas in A. prostratum). In addition, A. nebulosum differs from A. prostratum anatomically in having thicker leaflet blades composed of two to four layers of palisade parenchyma (vs. one to three layers in A. prostratum), and seven to eight layers in the spongy parenchyma (vs. six to eight layers in A. prostratum). A key for the identification of all species of Anemopaegma from the Atlantic Forest of Brazil is presented.


1991 ◽  
Vol 117 (2) ◽  
pp. 207-212 ◽  
Author(s):  
S. J. Wilcockson ◽  
A. E. Abuzeid

SUMMARYIn 1984 and 1985, the growth of axillary buds of Brussels sprouts plants was studied at Cockle Park, Northumberland, UK. Bud growth commenced in late September or early October and continued at all nodes until the final harvest in December. Total bud yield increased at a broadly constant rate until late November but at a decreasing rate thereafter. Plants produced c. 100 nodes with buds ≥ 5 mm diameter. The largest buds were c. 40 mm diameter and 25 g fresh weight. Bud size increased from the base of the stem upwards to between the 20th and 40th nodes and then decreased towards the apex. Nodes 20–40 (20% of the total) produced c. 40–45% of total bud yield. The size profile of leaves along the stem followed a similar pattern to the buds and the largest buds were in the axils of the largest leaves. There were close relationships between bud fresh weight and size, bud fresh weight and size, bud fresh weight and volume and log10 bud fresh weight and log10 bud size (r2 ≥ 0·995). The density of buds was c. 0·8 and bud fresh weight doubled for each 5 mm increase in bud diameter.Current photosynthesis of the leaf canopy was apparently the major source of assimilates for bud growth. A C14 tracing experiment suggested that growth of individual buds was mainly supported by their subtending leaves. There was no evidence of re-translocation of dry matter from dying leaves or the stems to buds or of substantial production of dry matter by the buds themselves. Rates of bud photosynthesis were only about 10% of the rate of leaves. The continued increase in bud fresh weight and size at the lowest nodes when leaves were senescing rapidly and after they had abscissed was probably mainly the result of water uptake rather than dry matter accumulation.


Development ◽  
1992 ◽  
Vol 115 (3) ◽  
pp. 745-753 ◽  
Author(s):  
V. F. Irish ◽  
I. M. Sussex

We have mapped the fate of cells in the Arabidopsis embryonic shoot apical meristem by irradiating seed and scoring the resulting clonally derived sectors. 176 white, yellow, pale green or variegated sectors were identified and scored for their position and extent in the resulting plants. Most sectors were confined to a fraction of a leaf, and only occasionally extended into the inflorescence. Sectors that extended into the inflorescence were larger, and usually encompassed about a third to a half of the inflorescence circumference. We also find that axillary buds in Arabidopsis are clonally related to the subtending leaf. Sections through the dry seed embryo indicate that the embryonic shoot apical meristem contains approximately 110 cells in the three meristematic layers prior to the formation of the first two leaf primordia. The histological analysis of cell number in the shoot apical meristem, in combination with the sector analysis have been used to construct a map of the probable fate of cells in the embryonic shoot apical meristem.


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