Showing papers on "Plant physiology published in 1987"
01 Jan 1987
72 citations
59 citations
TL;DR: In butterhead genotypes nitrate content was negatively correlated with dry matter content and positively with plant fresh weight, and within cultivated lettuce five plant types were distinguished and within each of them genotypes were found with low nitrates content.
Abstract: Nitrate content was measured in 135 genotypes of cultivated lettuce (Lactuca sativa L.) and 21 genotypes of wildLactuca spp. grown in two experiments. In Experiment 1 plants were grown on nutrient film. In Experiment 2 plants were grown in large pots of potting soil. Within cultivated lettuce five plant types were distinguished and within each of them genotypes were found with low nitrate content. The coefficient of variation in the experiment with plants growing in large pots was not larger than in the experiment with plants growing on nutrient film. In butterhead genotypes nitrate content was negatively correlated with dry matter content and positively with plant fresh weight.
54 citations
TL;DR: The basic hypothesis was WY that make, fern and plants capable of male and female sex expression (sexually IabUe) were equally vigorous as was manifeshd in chlorophyll and metabolite levels and that fourwing saltbusb has tbe capability of rebuilding its kvek of metabolitea in tbe spring at tbe pbydologically co&y time of flowering.
Abstract: An experiment WM conducted to determine if concentrations of chlorophyll and basic metabolite~ (total organic nitrogm (TN), total pbospborus (TP), and total nonstructural carbohydratea (TNC)) were an indication of tbe pbysiologkal vigor of tbe 3sexual pbenotypee of fourwing saltbusb (A&&&x canescens (Pursb) NM.). Our basic hypothesis WY that make, fern&s, and plants capable of male and female sex expression (sexually IabUe) were equally vigorous as was manifeshd in chlorophyll and metabolite levels. In June, concentntionr of cbloropbyU a, b, and total cbloropbyll in tbe m8le phenotype were grater than in either tbe female or tbe labile pbenotypeo. There were no differentamong phenotypes for tbe other dates. Male plants had tbe bigbest levelr of metabolites (TN, TP, and TNC) when any difference among sexual phenotypes were significant. There were baskally no differencea in metabolite concentration between the female and labile sexual phenotypes. Rewlts indiate thd pmt of the bypotbesir should be rejected-that male, female, and sexually labile plants are equ8lly vigorous based on concentr8tionr of chlorophyll 8nd metabolites. Part of tbe bypotbesis, however, can be acceptedtba1 femaks and kbUe planti are comparable in physiological vigor. Levek of all 3 metabolitea sbowed striking trends among sampk dates, which indiated that fourwing saltbusb has tbe capability of rebuilding its kvek of metabolitea in tbe spring at tbe pbydologically co&y time of flowering. Tbir may be related to the pbotosyntbetic efficiency associated with its C-4 pbotosyntbetic patbW8Y.
22 citations
TL;DR: The results suggest NADP-MDH and phospho-enolpyruvate carboxylase have important function(s) in the young leaf, which are not directly linked to C3 photosynthesis, and which, in part, may be linked to nitrate assimilation and provision of malate to mitochondria.
Abstract: The activity of NADP-malate dehydrogenase (NADP-MDH) was determined in the developing first leaf of the C3 plants wheat, barley and pea. Light dependent activation of the enzyme was observed in all three species following rapid extraction and immediate assay. Maximum activity was obtained following extraction from preilluminated leaves and incubation on ice for 45 min in the presence of dithiothreitol. In all three species, maximum activity was obtained in the young leaf 4 days after emergence of the seedling (about 2.5 to 3 μmoles per milligram chlorophyll per min in wheat and barley, and 6 μmoles per milligram chlorophyll per min in pea). On a chlorophyll basis there was an approximate five-fold decrease in NADP-MDH activity as the leaf matured. A similar pattern was found for phospho-enolpyruvate carboxylase and NADP-malic enzyme which had maximum activity in younger leaf tissue. Similarly, the activity of nitrate reductase in wheat and barley was high in the young leaf and it rapidly declined as the leaf matured. In contrast, the capacity for photosynthesis was relatively low in the young leaf, reaching a maximum 6 to 8 days after seedling emergence. The pattern of change in activity of phosphoribulokinase, an enzyme of the reductive pentose phosphate pathway, was similar to that of photosynthesis. The results suggest NADP-MDH and phospho-enolpyruvate carboxylase have important function(s) in the young leaf, which are not directly linked to C3 photosynthesis, and which, in part, may be linked to nitrate assimilation and provision of malate to mitochondria.
7 citations
TL;DR: A natural morphological variant of the species was isolated with a higher rate of photosynthesis than the normal plant, however, it has poor water use efficiency and low light saturation.
Abstract: SUMMARY Ougeinia delbergioides Benth. has potential as a multi-purpose tree for production of fodder and fuel wood. Seeds remained viable for more than a year and showed 60–80% germination favoured by temperatures of around 30°C. Active growth is from May to September with average 0.4583 mg CO2 m-s1 net photosynthesis and about 0.005 mg CO2/mg H20 water use efficiency. Photosynthesis does not get saturated even at full sunlight of around 1900 μE m-2s. A natural morphological variant of the species was isolated with a higher rate of photosynthesis than the normal plant. However, it has poor water use efficiency and low light saturation.
2 citations
TL;DR: Vitamin D3 was found to promote adventitious root formation in cuttings of Populus tremula and to promote the germination of lettuce seeds in the absence of light.
Abstract: The plant growth activity of vitamin D3 has been examined using well-established bioassays. Vitamin D3 was found to promote adventitious root formation in cuttings ofPopulus tremula and to promote the germination of lettuce (Lactuca sativa cv. Grand Rapids) seeds in the absence of light. No other effects were observed typical of plant growth substances.
2 citations