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31.
Growth and nutrient concentrations of alfalfa and common bean as influenced by soil acidity 总被引:2,自引:0,他引:2
Growth and nutrient utilization of alfalfa (Medicago sativa L. cv. Arc) and common bean (Phaseolus vulgaris L. cv. Carioca) were studied in an acid soil adjusted to eight levels of soil acidity by lime addition. Application of lime
significantly (P<0.05) increased shoot and root growth for both species. However, common bean was far less sensitive to soil acidity than
alfalfa. Maximum alfalfa growth was obtained at a soil pH of 5.8 and maximum bean growth was achieved at pH 5.0. Root and
shoot growth of both legumes was positively correlated (P<0.01) with soil pH, exchangeable Ca and exchangeable Mg and negatively correlated (P<0.01) with soil exchangeable Al. Common bean had a lower internal P requirement for maximum growth and was more efficient
than alfalfa in taking up Ca and Mg. These characteristics would contribute to the favorable growth of common bean in acid-infertile
soils. 相似文献
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Abstract An extensive literature survey of the host-range of Agrobacterium -induced neoplasms has revealed that highly susceptible plant families are accumulators of polyphenolics, whereas families assumed to be non-sensitive to the pathogen seem to lack this property. These and other results might indicate that polyphenolics play a role in the host-pathogen relationship of Agrobacterium -induced neoplasms. This hypothesis will be discussed in the light of the present knowledge of crown gall/hairy root induction and progress in plants. 相似文献
34.
The influence of phosphate nutrition on H ion efflux from the roots of young rape plants 总被引:3,自引:0,他引:3
Changes in pH around the roots of young rape plants were studied using a nutrient film technique which allowed either part
or all of the root system to be subjected to specific nutrient treatments. The rapidity and direction of change of pH was
assessed by embedding absorbing roots in a thin layer of agar containing bromocresol purple. Measurements were also made with
a pH microelectrode placed next to the roots.
Phosphate-fed plants were deprived of phosphate when 14 days old. Patterns of pH changes round the deprived roots were the
same as with phosphate-fed plants until the plants had been deprived of P for three days, when H ion efflux started in the
terminal portions of the roots. The lengths of root producing acid and amounts of H ion both increased as the plants became
more P deficient. Both P fed and P deprived roots produced HCO3 ions but the net amount of HCO3 ion produced by the P deficient roots fell as did nitrate uptake rates. Cation-anion balances measured at the end of the
experiment showed that uptake of all anions and K decreased in the P deprived plants but uptake of Ca and Mg were little altered.
This resulted in a smaller ratio of anions to cations absorbed which was reflected in the reduced HCO3 ion efflux. 相似文献
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Horizontal primary roots of Zea mays L. were photographed during the course of their gravireaction and during a preceding growth period in the vertical orientation. The displacement, by root elongation, of marker particles on the root surface was recorded. The particle-displacement rates were used to estimate the distribution of elemental elongation rates along opposite sides of the growing root apex. In the temperature range 21–25°C there was a stimulation of local elongation rates along the upper side of a gravireacting root and a reduction (and sometimes a cessation) of elongation along the lower side. Elemental elongation rates have been related to the development of root curvature, and the magnitude of the differential growth between upper and lower sides required for a particular rate of bending has also been estimated. The results complement, and are compatible with, findings relating to the distribution of certain endogenous growth regulators believed to participate in the gravireaction.Abbreviation RELEL
relative elemental rate of elongation 相似文献
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39.
《Journal of Plant Interactions》2013,8(3):263-270
Abstract Cd(II) adsorption of root exudates from sunflower (Helianthus annuus L.) seedling was investigated by Cd ion-selective electrode, Fourier Transform Infrared spectroscopy, and fluorescence spectroscopy. Root exudates from Helianthus annuus L. had strong adsorption ability toward Cd(II). The adsorption process was pH-dependent and the maximum adsorption capacity, 150.8 mg g?1, was observed at pH 7.0. Root exudates had pK a1 at 4.7 for carboxyl and pK a2 at 9.2 for phenolic, and amino groups. The aliphatic and aromatic (C?H) groups, amide III group, and the C (=O)?O and sulfonate groups were responsible for Cd(II) adsorption. The excitation emission matrix fluorescence spectroscopy showed protein-like substances participated in Cd adsorption and formed strong complexes, with conditional stability constants of 4.70 and 4.32, which is a little lower than that determined by potentiometric methods, 5.13. The strong Cd complexing ability of root exudates implies that root exudates may significantly affect mobility, toxicity, and phytoavailability of Cd. Cd binding of root exudates may be attributed to its interaction with the proteins, polysaccharides, and phenolic compounds in root exudates. 相似文献
40.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2762-2765
Comparative two-dimensional electrophoresis showed six proteins, which were significantly produced in the root of salt-tolerant barley. These proteins were identified as stress/defense-related proteins that do not scavenge reactive oxygen species directly, suggesting that salt-tolerant barley develops not only an antioxidative system, but also physical and biochemical changes to cope with salt stress. 相似文献