Intake of labelled nutrient by Heterodera elachista at different developmental stages

概要

論文の詳細を見る
Relationships between developmental stages and amount of nutrient taken in by the rice cyst nematode, Heterodera elachista, were studied using substances labelled by the radioactivity. Rice seedlings were grown at constant 25°C in sterile sand on a screen sieve so that the roots can grow through the screen into a cup of nutrient solution. Water suspension of 77, 000 larvae per cup was added to the sterile sand 1 month after sowing. The inoculation was accomplished by replacing the infected sand by sterile one after 48 hr. The culture solution was replaced by the radioactive one 1) every 3 days until the last stage of nematode, or 2) for a limited period, that is, 32 P-orthophosphate for 3 days and 14C-urea for 5 days. The radioactivity of about 10 dried nematode specimens separated from the root tissues was measured by a windowless gas-flow counter. The amount of intake of radioactive substances during every 3 days increased gradually from the second larval stage to the fourth one with a peak shown by matured females which actively deposited eggs into the gelatinous matrix (23-26 days after inoculation). None of the intake was indicated 40 days after inoculation. Ratio of radiophosphorus content in the second stage larvae to that in the adults was 1 to 140, and ratio of radiocarbon was 1 to 4. Those ratios of radiophosphorus and radiocarbon contents in egg masses to adult females were about 15% and 55%, respectively.
日本線虫学会の論文