Effects of Root Pruning on Cucumber Seedling Growth

Phenolic compounds enter soil as a result of root exudation and plant residue decomposition, but their impacts on soil microbial communities are poorly understood. In this experiment, effects of syringic acid on cucumber rhizosphere microbial communities were evaluated. Rhizosphere bacterial and fungal community structures and abundances were analyzed with PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative PCR, respectively. Results showed that syringic acid inhibited cucumber seedling growth at concentrations of 0.05 to 0.2 μmol/g soil, and increased rhizosphere soil dehydrogenase activity, microbial biomass carbon content, bacterial 16S rRNA gene and fungal ITS rRNA gene densities, and decreased the bacteria-to-fungi ratio at concentrations of 0.02 to 0.2 μmol/g soil. Syringic acid also changed rhizosphere bacterial and fungal community structures: it decreased the richness, evenness, and diversity indices of rhizosphere bacterial community but had no significant influences on that of fungal community, indicating that syringic acid had different influence on bacterial and fungal communities. Taken together, these results showed that syringic acid inhibited cucumber growth and altered rhizosphere microbial communities, suggesting that syringic acid plays some role in the communication between plants and soil microorganisms.

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Morphological and physiological attributes of root systems and seedling growth in three different Picea glauca reforestation stock

Canadian Journal of Forest Research ◽

10.1139/x00-093 ◽

2000 ◽

Vol 30 (11) ◽

pp. 1669-1681 ◽

Cited By ~ 7

Author(s):

M J Krasowski ◽

J N Owens

Keyword(s):

Root System ◽

Seedling Growth ◽

Picea Glauca ◽

Root Systems ◽

Growing Season ◽

System Size ◽

The Other ◽

Root Pruning ◽

Growing Seasons ◽

Forest Sites

The relationship between certain morphological characteristics of white spruce (Picea glauca (Moench) Voss) planting stock (STK) and post-planting seedling performance was evaluated. Root system size at planting, its expansion, and its capacity to conduct water during the first post-planting weeks were determined. These characteristics were related to the performance of STK planted on two forest sites and measured for three growing seasons and to the performance of seedlings grown in large wooden boxes buried in the soil outdoors for one growing season (grown without competition from other vegetation). The compared STK were (i) polystyroblock grown, (ii) polystyroblock grown with chemical root pruning, and (iii) peat-board grown with mechanical root pruning. After three growing seasons on forest sites, seedlings with mechanically pruned roots grew more above ground than did seedlings from polystyroblock containers. This difference in seedling growth performance was even more significant for seedlings grown in wooden boxes. Of these, the mechanically pruned seedlings grew more not only above the ground but they also produced larger root systems by the end of the first growing season. This was despite the initially significantly smaller root systems of mechanically pruned seedlings, compared with the other two STK. Early (5-7 weeks after planting) post-planting root expansion patterns in the three STK were significantly different, with the roots of mechanically pruned seedlings growing less than the roots in the other two STK. In spite of this, pressure-probe measured hydraulic conductivity and water flux through root systems increased during the first post-planting weeks in mechanically pruned seedlings while declining or changing little in the other two STK. It was concluded that root system size at planting and its early post-planting expansion did not relate well to the root system hydraulic properties or to the post-planting seedling growth performance.

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Pruning Northern Red Oak Nursery Seedlings: Effects on Root Regeneration and Early Growth

Canadian Journal of Forest Research ◽

10.1139/x75-052 ◽

1975 ◽

Vol 5 (3) ◽

pp. 381-386 ◽

Cited By ~ 10

Author(s):

M. M. Larson

Keyword(s):

Seedling Growth ◽

Shoot Growth ◽

Late Summer ◽

Early Growth ◽

Red Oak ◽

Root Pruning ◽

Root Weight ◽

Northern Red Oak ◽

Root Regeneration ◽

Early Fall

Northern red oak seedlings were top-pruned in the seedbed each month from August until the next March. In late March, all trees were lifted, planted in the greenhouse, and harvested 30 days later. Any top-pruning treatment that directly or indirectly removed the leaves in late summer or early fall markedly reduced root regeneration and initial shoot growth after planting in March. Removal of all the visible buds at any date resulted in increased numbers of new shoots after planting, while pruning stems at the groundline reduced new shoot growth.In additional studies, shoots and roots of trees lifted in March were pruned to various levels before planting. Results indicated that root pruning influenced seedling growth much more than shoot pruning. The amount of new shoot growth was significantly correlated with root weight of seedlings when planted, whether differences in root weight were natural or obtained by pruning. The effects of shoot pruning and root pruning on seedling growth were largely independent of each other.

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Soil phenolics in a continuously mono-cropped cucumber (Cucumis sativus L.) system and their effects on cucumber seedling growth and soil microbial communities

European Journal of Soil Science ◽

10.1111/j.1365-2389.2012.01442.x ◽

2012 ◽

Vol 63 (3) ◽

pp. 332-340 ◽

Cited By ~ 35

Author(s):

X. Zhou ◽

G. Yu ◽

F. Wu

Keyword(s):

Microbial Communities ◽

Cucumis Sativus ◽

Seedling Growth ◽

Soil Microbial Communities ◽

Cucumber Seedling ◽

Cucumis Sativus L ◽

Soil Microbial ◽

L System ◽

Soil Phenolics

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24-Epibrassinolide Ameliorates Endogenous Hormone Levels to Enhance Low-Temperature Stress Tolerance in Cucumber Seedlings

International Journal of Molecular Sciences ◽

10.3390/ijms19092497 ◽

2018 ◽

Vol 19 (9) ◽

pp. 2497 ◽

Cited By ~ 16

Author(s):

Ali Anwar ◽

Longqiang Bai ◽

Li Miao ◽

Yumei Liu ◽

Shuzhen Li ◽

...

Keyword(s):

Gene Expression ◽

Low Temperature ◽

Antioxidant Enzyme ◽

Temperature Stress ◽

Seedling Growth ◽

Photosynthetic Capacity ◽

Low Temperature Stress ◽

Endogenous Hormones ◽

Cucumber Seedling ◽

Biosynthesis Gene

Phytohormone biosynthesis and accumulation are essential for plant growth and development and stress responses. Here, we investigated the effects of 24-epibrassinolide (EBR) on physiological and biochemical mechanisms in cucumber leaves under low-temperature stress. The cucumber seedlings were exposed to treatments as follows: NT (normal temperature, 26 °C/18 °C day/night), and three low-temperature (12 °C/8 °C day/night) treatments: CK (low-temperature stress); EBR (low-temperature and 0.1 μM EBR); and BZR (low-temperature and 4 μM BZR, a specific EBR biosynthesis inhibitor). The results indicated that low-temperature stress proportionately decreased cucumber seedling growth and the strong seedling index, chlorophyll (Chl) content, photosynthetic capacity, and antioxidant enzyme activities, while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) contents, hormone levels, and EBR biosynthesis gene expression level. However, EBR treatments significantly enhanced cucumber seedling growth and the strong seedling index, chlorophyll content, photosynthetic capacity, activities of antioxidant enzymes, the cell membrane stability, and endogenous hormones, and upregulated EBR biosynthesis gene expression level, while decreasing ROS and the MDA content. Based on these results, it can be concluded that exogenous EBR regulates endogenous hormones by activating at the transcript level EBR biosynthetic genes, which increases antioxidant enzyme capacity levels and reduces the overproduction of ROS and MDA, protecting chlorophyll and photosynthetic machinery, thus improving cucumber seedling growth.

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