scholarly journals In Vitro and ex Vitro Adventitious Root Formation in Asian Jasmine (Trachelospermum asiaticum) I. Comparative Morphology

1993 ◽  
Vol 118 (6) ◽  
pp. 902-905 ◽  
Author(s):  
R.C. Apter ◽  
E.L. McWilliams ◽  
F.T. Davies

One-node explants and one-node stem cuttings of Asian jasmine [Trachelospermum asiaticum (Siebold & Zucc.) Nakai] were rooted, respectively, in vitro [tissue culture (TC)] or by conventional macropropagation (MACRO). The TC and MACRO stem bases were then analyzed for differences in the time-course sequence of 1) root primordia initiation and development and 2) adventitious root xylem development and root-to-shoot xylem connections. Early root primordia were observed at Day 3, and, by Day 7, root-to-shoot xylem connections were equally developed in TC and MACRO systems. Continued development and emergence of adventitious roots were observed at Days 8 to 10. At Days 13 and 18, when viewed using scanning electron microscopy, TC root hairs were morphologically thicker and one-third to one-half the length of MACRO root hairs. There was no apparent difference in root-hair density. Inferior TC root-hair length may be a factor in the acclimation of TC-generated plantlets.

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 634b-634
Author(s):  
Rolston St. Hilaire ◽  
Carlos A. Fierro Berwart

Mussaendas (Mussaenda spp.) are ornamental shrubs, and some cultivars are difficult to root. This study was conducted to explore how adventitious roots initiate and develop in the cultivar Rosea, and to determine if anatomical events are associated with difficulty in rooting stem cuttings. Stem cuttings were treated with 5, 10, 15 mm 1H-indole-3-butyric acid (IBA), or distilled water, and sampled every 2 days over 26 days to observe adventitious root formation and development. For analysis by light microscopy, the basal 1 cm of cuttings was embedded in wax and stained with safranin-fast green. Adventitious roots initiated from phloem parenchyma cells and from basal callus in nontreated cuttings. Cuttings treated with 15 mm IBA had a mean of 18 root primordia per basal 1 cm of cutting after 10 days. Root primordia were not observed in non-treated cuttings at 10 days. Root primordia that developed in non-treated cuttings lacked clear vascular connections. These results suggest that non-treated cuttings are difficult to root because few primordia are produced.


HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 1023-1025 ◽  
Author(s):  
Rolston St. Hilaire ◽  
Carlos A. Fierro Berwart ◽  
Carlos A. Pérez-Muñoz

Mussaendas (Mussaenda spp.) are ornamental shrubs, and some cultivars are difficult to root. This study was conducted to explore how adventitious roots initiate and develop in the cultivar Rosea and to determine if anatomical events are associated with difficulty in rooting stem cuttings. Stem cuttings were treated with 5, 10, 15 mmol IBA, or distilled water, and sampled every 2 days over 26 days to observe adventitious root formation and development. Adventitious roots initiated from phloem parenchyma cells. Cuttings treated with 15 mmol IBA had a mean of 18 root primordia per basal 1 cm of cutting after 10 days. Primordia were absent in nontreated cuttings at 10 days. These results suggest that nontreated cuttings are difficult to root because few primordia are produced. Chemical name used: 1H-indole-3-butyric acid (IBA).


1991 ◽  
Vol 39 (4) ◽  
pp. 435-440 ◽  
Author(s):  
M J Bodson ◽  
W H Outlaw ◽  
S H Silvers

Malate, which plays many essential roles in plant metabolism, is a potent in vitro inhibitor of the cytosolic enzyme phosphoenolpyruvate carboxylase (PEPC). Because PEPC activity leads to malate biosynthesis, malate is assumed to attenuate its own synthesis in situ. To test this hypothesis, we measured directly the malate content of picoliter samples of Raphanus root-hair cytoplasm using quantitative histochemical techniques. We also obtained an estimate for malate accumulation in these cells. These values were compared with the PEPC activity of individual root hairs (less than 2 ng). The results indicate that high cytoplasmic malate concentration does not severely inhibit PEPC in situ. We suggest that the focus for studies on the regulation of organic anion accumulation be on the interactive effects of malate and other PEPC effectors.


2019 ◽  
Author(s):  
Changzheng Xu ◽  
Yuanxun Tao ◽  
Xiaokang Fu ◽  
Li Guo ◽  
Haitao Xing ◽  
...  

AbstractAdventitious root (AR) formation at the base of stem cuttings determines the efficiency of clonal propagation for woody plants. Many endogenous and environmental factors influence AR formation. However, our knowledge about the regulation of AR development by mitochondrial metabolism in plants is very limited. Here we identified Populus-specific miR476a as a novel regulator of wound-induced adventitious rooting via orchestrating mitochondrial homeostasis in poplar. MiR476a exhibited inducible expression during AR formation and directly targets several Restorer of Fertility like (RFL) genes encoding mitochondrion-localized pentatricopeptide repeat proteins. Genetic modification of miR476-RFL expression revealed the miR476/RFL-mediated dynamic regulation of mitochondrial homeostasis on AR formation in transgenic poplar. Furthermore, mitochondrial perturbation via exogenous chemical inhibitor validated that the miR476a/RFL-directed AR formation depended on mitochondrial regulation though modulating the auxin pathway. Our results established a miRNA-directed mitochondrion-auxin signaling cascade required for AR development, providing novel insights into the understanding of mitochondrial regulation on plant developmental plasticity.


2008 ◽  
Vol 133 (4) ◽  
pp. 479-486 ◽  
Author(s):  
J. Naalamle Amissah ◽  
Dominick J. Paolillo ◽  
Nina Bassuk

This study investigated the relationship of stem anatomy to differences in rooting ability between Quercus bicolor Wild. and Quercus macrocarpa Michx. cuttings. Quercus bicolor cuttings were found to have a significantly greater proportion of parenchymatous gaps in the sclerenchyma sheath over a 9-week period compared with Q. macrocarpa cuttings. In Q. macrocarpa, the percentage gap was generally low, coinciding with the low percentage rooting observed in this species. Percentage rooting correlated well (r2 = 0.75) with the percentage parenchymatous gap in the perivascular region of Q. bicolor cuttings. The problems with accepting this relationship as causal are stated in the discussion. Untreated cuttings showed normal stem organization: a dermal tissue system that included the initial stages of phellem formation, a cortex, and a ring of closely arranged vascular bundles in early stages of secondary growth. The locations of the five distinct lobes of the pith were coordinated with the locations of root primordia. Callus growth was first detected in the cortex (i.e., external to the fiber bundles), followed by proliferation within the phloem, opposite the lobes of the pith, 8 to 12 days after cuttings were treated with indole butyric acid (6000 mg·L−1 dissolved in 50% v/v ethanol in water). By 14 to 16 days, root primordia had developed within the proliferative tissue in the secondary phloem. In both species, root primordia penetrated parenchymatous gaps in the fiber sheath directly, the fiber bundles being displaced laterally as the roots increased in size.


BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Carlos Villacorta-Martín ◽  
Ana Belén Sánchez-García ◽  
Joan Villanova ◽  
Antonio Cano ◽  
Miranda van de Rhee ◽  
...  

HortScience ◽  
2020 ◽  
Vol 55 (9) ◽  
pp. 1463-1467 ◽  
Author(s):  
Benjamin E. Deloso ◽  
Anders J. Lindström ◽  
Frank A. Camacho ◽  
Thomas E. Marler

The influences of indole-3-butyric acid (IBA) concentrations of 0–30 mg·g−1 on the success and speed of adventitious root development of Zamia furfuracea L.f. and Zamia integrifolia L.f. stem cuttings were determined. Root formation success for both species was greater than 95%. The IBA concentrations did not influence the speed of root development for Z. furfuracea, but the Z. integrifolia cuttings that received IBA concentration of 3 mg·g−1 generated adventitious roots more slowly than the cuttings in the control group. The ending dry weights of the stems, leaves, and roots were not influenced by IBA concentration for either species. Our results indicated that adventitious root formation on stem cuttings of these two Zamia species is successful without horticultural application of IBA. Additional IBA studies are needed on the other 300+ cycad species, especially those that are in a threatened category.


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