scholarly journals Metabolite mobilization in the stem galls of Parthenium hysterophorus induced by Epiblema strenuana inferred from the signatures of isotopic carbon and nitrogen and concentrations of total non-structural carbohydrates

2006 ◽  
Vol 119 (2) ◽  
pp. 101-107 ◽  
Author(s):  
A. Raman ◽  
S. Madhavan ◽  
S.K. Florentine ◽  
K. Dhileepan
Keyword(s):  
Parthenium Hysterophorus ◽  
Carbon And Nitrogen ◽  
Epiblema Strenuana

Seasonal variation in the effectiveness of the leaf-feeding beetle Zygogramma bicolorata (Coleoptera: Chrysomelidae) and stem-galling moth Epiblema strenuana (Lepidoptera: Tortricidae) as biocontrol agents on the weed Parthenium hysterophorus (Asteraceae)

2003 ◽  
Vol 93 (5) ◽  
pp. 393-401 ◽  
Author(s):  
K. Dhileepan
Keyword(s):  
Seed Bank ◽  
Negative Impact ◽  
Soil Seed Bank ◽  
Summer Rainfall ◽  
Biocontrol Agents ◽  
Parthenium Hysterophorus ◽  
Exclusion Experiment ◽  
Limited Impact ◽  
Zygogramma Bicolorata ◽  
Epiblema Strenuana

AbstractVariation in the effectiveness of biocontrol agents on the weed Parthenium hysterophorus L. was evaluated at two properties (Mount Panorama and Plain Creek) in Queensland, Australia for four years (1996–2000) using a pesticide exclusion experiment. At Mount Panorama, higher levels of defoliation by the leaf-feeding beetle Zygogramma bicolorata Pallister and galling by the moth Epiblema strenuana Walker in 1996–97 coincided with an above average summer rainfall, but in the following three years with below average summer rainfall the defoliation and galling levels were significantly lower. Biocontrol had significant negative impact on the weed only in 1996–97 with no major impact in the following three years. At Plain Creek, galling by E. strenuana was evident in all the four years, but varied significantly between years due to non-synchrony between P. hysterophorus germination and E. strenuana emergence. At Plain Creek biocontrol had limited impact on the weed in 1996–97 and 1997–98, with no significant impact in the following two years. Over the 4-year period, defoliation and galling resulted in 70% reduction in the soil seed bank at Mount Panorama, but the reduction in the soil seed bank at Plain Creek due to galling was not significant. Effectiveness of Z. bicolorata and E. strenuana was dependent on weather conditions and as a result had only limited impact on the weed in three out of four years.

Metabolic signalling and the partitioning of resources in plant storage organs

1999 ◽  
Vol 133 (3) ◽  
pp. 243-249 ◽  
Author(s):  
NIGEL G. HALFORD
Keyword(s):  
Dry Weight ◽  
Wild Relatives ◽  
Crop Plants ◽  
Wild Plants ◽  
Young Plant ◽  
Carbon And Nitrogen ◽  
Cultivated Potato ◽  
Metabolic Signalling ◽  
Storage Organs ◽  
Plant Storage

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

Precipitation in silicon: Microanalysis

1988 ◽  
Vol 46 ◽  
pp. 474-475
Author(s):  
R.W. Carpenter
Keyword(s):  
Transition Metals ◽  
Spatial Resolution ◽  
Thin Foil ◽  
Precipitation Reaction ◽  
High Current ◽  
Reaction Products ◽  
Carbon And Nitrogen ◽  
Dielectric Layers ◽  
Precipitation Processes ◽  
Areas Of Interest

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.

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