Effects of Girdling and Defoliation on Root Activity and Survival of Eucalyptus regnans and E. viminalis Seedlings

1975 ◽  
Vol 2 (2) ◽  
pp. 197 ◽  
Author(s):  
BF Wilson ◽  
EP Bachelard
Keyword(s):  
Amino Acids ◽  
Root Growth ◽  
Root Elongation ◽  
Root Activity ◽  
Eucalyptus Regnans ◽  
Total Sugars ◽  
Fast Growing ◽  
Qualitative Changes

Fast-growing seedlings of E. regnans F.Muell. survive when bark-girdled, but die when defoliated or detopped or when the stem at a bark girdle is steam-killed. These differences are due to photosynthate passing bark birdles in large quantities, probably in internal primary phloem. Following defoliation or detopping, root elongation stops within 4 days, the root sap turns brown within 8-13 days, and the plant dies in 12-30 days. Total sugars and amino acids in the root sap changed only slightly following girdling or up to 8 days after detopping, but both increased tenfold 8-13 days after detopping. This increase is accompanied by qualitative changes in both sugars and amino acids, and by the appearance of inhibitor(s). Gibberellin and cytokinin activities in the sap are not affected by girdling or detopping. In contrast, fast-growing seedlings of E. viminalis Labill. survive detopping and, although root growth stops by 4 days, root sap stays colourless and without inhibitors.

scholarly journals Genome-wide identification and transcriptional analyses of MATE transporter genes in root tips of wild Cicer spp. under aluminium stress

2020 ◽  
Author(s):  
Xia Zhang ◽  
Brayden Weir ◽  
Hongru Wei ◽  
Zhiwei Deng ◽  
Xiaoqi Zhang ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Elongation ◽  
Transcriptional Profiling ◽  
Functional Characterization ◽  
Relative Reduction ◽  
Root Tips ◽  
Al Tolerance ◽  
Genome Wide ◽  
Encoding Genes ◽  
Al Treatment

AbstractChickpea is an economically important legume crop with high nutritional value in human diets. Aluminium-toxicity poses a significant challenge for the yield improvement of this increasingly popular crop in acidic soils. The wild progenitors of chickpea may provide a more diverse gene pool for Al-tolerance in chickpea breeding. However, the genetic basis of Al-tolerance in chickpea and its wild relatives remains largely unknown. Here, we assessed the Al-tolerance of six selected wild Cicer accessions by measuring the root elongation in solution culture under control (0 µM Al3+) and Al-treatment (30 µM Al3+) conditions. Al-treatment significantly reduced the root elongation in all target lines compared to the control condition after 2-day’s growth. However, the relative reduction of root elongation in different lines varied greatly: 3 lines still retained significant root growth under Al-treatment, whilst another 2 lines displayed no root growth at all. We performed genome-wide identification of multidrug and toxic compound extrusion (MATE) encoding genes in the Cicer genome. A total of 56 annotated MATE genes were identified, which divided into 4 major phylogeny groups (G1-4). Four homologues to lupin LaMATE (> 50% aa identity; named CaMATE1-4) were clustered with previously characterised MATEs related to Al-tolerance in various other plants. qRT-PCR showed that CaMATE2 transcription in root tips was significantly up-regulated upon Al-treatment in all target lines, whilst CaMATE1 was up-regulated in all lines except Bari2_074 and Deste_064, which coincided with the lines displaying no root growth under Al-treatment. Transcriptional profiling in five Cicer tissues revealed that CaMATE1 is specifically transcribed in the root tissue, further supporting its role in Al-detoxification in roots. This first identification of MATE-encoding genes associated with Al-tolerance in Cicer paves the ways for future functional characterization of MATE genes in Cicer spp., and to facilitate future design of gene-specific markers for Al-tolerant line selection in chickpea breeding programs.

scholarly journals Root Growth of Avocado is More Sensitive to Salinity than Shoot Growth

2004 ◽  
Vol 129 (2) ◽  
pp. 188-192 ◽  
Author(s):  
N. Bernstein ◽  
A. Meiri ◽  
M. Zilberstaine
Keyword(s):  
Salt Stress ◽  
Root Growth ◽  
Biomass Production ◽  
Root Elongation ◽  
Shoot Growth ◽  
Elongation Rate ◽  
Persea Americana ◽  
Root Growth Inhibition ◽  
Leaf Biomass ◽  
Volumetric Growth

In most crop species, growth of the shoot is more sensitive to salt stress than root growth. Avocado [Persea americana Mill.] is very sensitive to NaCl stress. Even low concentrations of salt (15 mm) inhibit tree growth and decrease productivity. Observations in experimental orchards have suggested that root growth in avocado might be more restricted by salinity than shoot growth. In the present study, we evaluated quantitatively the inhibitory effects of salt stress on growth of the avocado root in comparison to the shoot. Seedling plants of the West-Indian rootstock `Degania 117' were grown in complete nutrient solution containing 1, 5, 15, or 25 mm NaCl. The threshold NaCl concentration causing root and shoot growth reduction occurred between 5 and 15 mm. At all concentrations, root growth was much more sensitive to salinity than shoot growth. A concentration of 15 mm NaCl, which did not affect the rate of leaf emergence on the plant and decreased leaf biomass production only 10%, induced a 43% reduction in the rate of root elongation and decreased root volumetric growth rate by 33%. Under 25 mm NaCl, leaf biomass production, leaf initiation rate and leaf elongation rate were reduced 19.5%, 12%, and 5%, respectively, while root volumetric growth and root elongation rate were reduced 65% and 75%, respectively. This strong root growth inhibition is expected to influence the whole plant and therefore root growth under salinity should be considered as an important criterion for rootstocks' tolerance to NaCl.

The effect of Cylindrocarpon destructans on the growth of Eucalyptus regnans seedlings in air-dried and undried forest soil

2010 ◽  
Vol 58 (2) ◽  
pp. 133 ◽  
Author(s):  
T. M. Iles ◽  
D. H. Ashton ◽  
K. J. Kelliher ◽  
P. J. Keane
Keyword(s):  
Root Growth ◽  
Forest Soil ◽  
Seedling Growth ◽  
Frequency Of Occurrence ◽  
Root Tips ◽  
Eucalyptus Regnans ◽  
Cylindrocarpon Destructans ◽  
Pot Experiments ◽  
Growth Of Seedlings

The growth of Eucalyptus regnans F.Muell. (mountain ash) seedlings is poor in natural forest soil, where purple coloration of the foliage indicates P deficiency and where the fungus Cylindrocarpon destructans (Zinsm.) Scholten is commonly isolated from the roots of the seedlings. When forest soil is air-dried, P acquisiton and growth of seedlings are markedly improved, although the degree of growth stimulation varies considerably at different times, as does the frequency of occurrence of C. destructans on the roots. C. destructans has been implicated as a possible reason for suppressed growth of seedlings in undried natural soil. To find out whether C. destructans contributes to growth inhibition of E. regnans seedlings in undried forest soil, the effect of three isolates of C. destructans on the root growth of E. regnans seedlings was tested in Petri dish experiments in vitro and the effect of C. destructans inoculation on seedling growth both in air-dried and undried forest soil was tested in pot experiments. The frequency of occurrence of C. destructans on the roots varied at different times, and was not consistently higher in undried than in air-dried soil, even though the growth of the seedlings was always poor in undried soil compared with that in air-dried soil. In vitro, C. destructans decreased the root growth significantly and caused blackening of root tips. This effect was removed by adding natural air-dried or undried soil. In pot experiments using undried forest soil, there was no evidence of either direct toxic effect or any other adverse effect on the roots when soil was inoculated with this fungus, even when the growth of the seedlings was reduced to ~1/2 of that in uninoculated undried soil. In air-dried soil, inoculation with the fungus did not significantly reduce seedling growth. Although potentially pathogenic and able to cause blackening of root tips, C. destructans is unlikely to be the main reason for poor seedling growth in undried forest soil. It appears to be antagonistic rather than pathogenic, suppressing seedling growth only under unfavourable conditions, such as in undried soil, possibly by competing for limited nutrients, or by suppressing other beneficial micro-organisms. The results are discussed in the context of field conditions.

Genetic variation in the root growth response of barley genotypes to salinity stress

2013 ◽  
Vol 40 (5) ◽  
pp. 516 ◽  
Author(s):  
Megan C. Shelden ◽  
Ute Roessner ◽  
Robert E. Sharp ◽  
Mark Tester ◽  
Antony Bacic
Keyword(s):  
Genetic Variation ◽  
Salt Stress ◽  
Root Growth ◽  
Salinity Stress ◽  
Early Phase ◽  
Root Elongation ◽  
Wild Barley ◽  
Seminal Root ◽  
Biochemical Characterisation ◽  
Barley Genotypes

We aimed to identify genetic variation in root growth in the cereal crop barley (Hordeum vulgare L.) in response to the early phase of salinity stress. Seminal root elongation was examined at various concentrations of salinity in seedlings of eight barley genotypes consisting of a landrace, wild barley and cultivars. Salinity inhibited seminal root elongation in all genotypes, with considerable variation observed between genotypes. Relative root elongation rates were 60–90% and 30–70% of the control rates at 100 and 150 mM NaCl, respectively. The screen identified the wild barley genotype CPI71284–48 as the most tolerant, maintaining root elongation and biomass in response to salinity. Root elongation was most significantly inhibited in the landrace Sahara. Root and shoot Na+ concentrations increased and K+ concentrations decreased in all genotypes in response to salinity. However, the root and shoot ion concentrations did not correlate with root elongation rates, suggesting that the Na+ and K+ concentrations were not directly influencing root growth, at least during the early phase of salt stress. The identification of genetic diversity in root growth responses to salt stress in barley provides important information for future genetic, physiological and biochemical characterisation of mechanisms of salinity tolerance.

scholarly journals Root Growth, Free Amino Acids, and Carbohydrates of Tall Fescue in Response to Soil Salinity

HortScience ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 609-614 ◽  
Author(s):  
Yong Yang ◽  
Xueyong Liu ◽  
Yuanli Jiang ◽  
Zuoxiang Xiang ◽  
Qingguo Xu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Plant Growth ◽  
Root Growth ◽  
Soil Salinity ◽  
Tall Fescue ◽  
Free Amino ◽  
Saline Soil ◽  
Soluble Sugars ◽  
Organic Fertilizers ◽  
Deep Soil

Salt-affected soils may retard plant growth and cause metabolic alterations. The objective of this study was to investigate the effect of salinity in deep soil on root growth and metabolic changes of tall fescue (Festuca arundinacea). Tall fescue seeds (cv. Houndog V) were planted in polyvinylchloride (PVC) tubes (9 cm diameter × 45 cm long) for 2 months with three treatments of growth substances: (1) control, filled with peat-sand mixtures for full tubes (40 cm height, sand:organic fertilizers = 7:3, w/w); (2) T20, 20 cm saline soil covered with 20 cm organic fertilizers and sand; (3) T30, 30 cm saline soil covered with 10 cm organic fertilizers and sand. Turf quality and vertical shoot growth rate (VSGR) significantly decreased in T30, but not for T20, when compared with the control. Salinity in deep soil obviously inhibited the root growth as indicated by the lower root length, root projected area, root diameter, root fresh, and dry weight, but increased the level of amino acids (Asp, Glu, Ser, Gly, etc.) and soluble sugars (glucose, fructose, sucrose). Root activity in top layer (0–10 cm) of saline soil increased while decreased in deeper layer (20–40 cm) when compared with the control. The increase of root activity and free amino acids in roots from upper layer and the accumulation of soluble sugars in roots from deeper soil layer under salinity conditions were the adaptive responses and regulative mechanisms that for supporting the above-ground plant growth in tall fescue when exposed to deep soil salinity conditions. These results also suggested that a 20 cm of improved mixture of organic fertilizers with sand on the top of saline soil could be sufficient to supply basic space for the normal growth of turfgrass with regular spray irrigation.

Effect of aluminium on root elongation in two Australian perennial grasses

1998 ◽  
Vol 25 (2) ◽  
pp. 165 ◽  
Author(s):  
Simon A. Crawford ◽  
Sabine Wilkens
Keyword(s):  
Root Growth ◽  
Root Elongation ◽  
Root Apex ◽  
Perennial Grasses ◽  
Root Tips ◽  
Al Stress ◽  
Control Growth ◽  
Hematoxylin Staining ◽  
Inhibition Of Root Elongation ◽  
Nutrient Solutions

Inhibition of net root elongation and patterns of hematoxylin staining were used to assess relative tolerance to phytotoxic Al in Danthonia linkii Kunth and Microlaena stipoides (Labill.) R.Br. According to net root elongation, M. stipoides is significantly more tolerant of phytotoxic Al than D. linkii. In nutrient solutions with Al concentrations of 370 µM and higher, root elongation is stopped in D. linkii after 24 h while in M. stipoides root elongation is maintained at 60–70% of control rates over 72 h. After removal of Al-stress, root growth in M. stipoides from all Al-treatments recovered to be at or above control growth after 72 h. In D. linkii, root elongation in plants exposed to Al levels that caused a reduction in growth (<370 µM), but not complete cessation, recovered after removal of Al stress. Greater intensities of hematoxylin staining were seen in Al-stressed root tips of D. linkii compared to M. stipoides, suggesting that inhibition of root elongation is associated with increased accumulation of Al in root tips. Roots of M. stipoides seedlings exposed to all Al-treatments showed a short band of intensely stained tissue, correlating with the position of the root apex at the exact point of initial Al- exposure. New root growth after this band did not stain with hematoxylin, indicating activation of a mechanism of Al-exclusion in roots of M. stipoides.

BORON INCREASES THE GROWTH AND YIELD OF MUNGBEAN

2016 ◽  
Vol 6 (2) ◽  
pp. 922-924
Author(s):  
Muhammad Asghar Ali
Keyword(s):  
Root Growth ◽  
Vigna Radiata ◽  
Growth And Development ◽  
Nutritional Value ◽  
Root Elongation ◽  
Nitrogen Assimilation ◽  
Animal Feed ◽  
Negative Impact ◽  
Growth And Yield ◽  
Positive Effect

Pulses have significant role in the profitability of agriculture because of major proportion of our population depends on it due to its higher nutritional value, rich source of protein and low price. Pulses are also important component of animal feed and their dried straw is used as hay. In pulses, mungbean (Vigna radiata L.) is a vital crop. Boron has positive effect on growth and development, nitrogen assimilation and root growth. Low level of boron causes negative impact on growth, narrow leave expansion, restricted root elongation and morphological features of mungbean plant.

Effects on Plant Growth of Material from Hydrothermal Humification Process of Biomass

2011 ◽  
Vol 322 ◽  
pp. 43-46
Author(s):  
Shu Qing Guo ◽  
Xiang Yuan Dong
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Root Growth ◽  
Root Elongation ◽  
Organic Fertilizer ◽  
Incubation Experiment ◽  
Negative Effects ◽  
Plant Seed ◽  
Positive Effects ◽  
Wet Weight

Hydrothermal humification (HTH) is a novel way to treat biomass in order to produce soil conditioner or organic fertilizer. A plant seed germination technique was used to assess the effect of HTH material derived from garden waste on seed germination, root elongation and germination index (GI) of cucumber at different stages of incubation. The incubation experiment was carried out with the mixture of HTH material and soil at a ratio of 1:3, 1:5 and 1:10 (HTH material:soil, wet weight) in soil. The results showed there are direct positive effects of the HTH material on seed germination and root growth. GI all were over 80%. High addition rates had non significantly negative effects on plant growth.

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