EFFECT OF EXTERNAL NITRATE CONCENTRATIONS ON NITRATE EFFLUX FROM ROOTS AND ACCUMULATION IN TWO BRASSICA NAPUS L. CULTIVARS |
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| Authors: | Caibian Huang Zhaohui Wang Shengxiu Li Jeff William Gale |
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| Institution: | 1. College of Resources and Environmental Science , Northwest Agriculture and Forestry University , Yangling, China;2. Xinjiang Institute of Ecology and Geography , Chinese Academy of Sciences , Urumqi, China;3. College of Resources and Environmental Science , Northwest Agriculture and Forestry University , Yangling, China |
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| Abstract: | The nutrient solution was replaced on day 72 after sowing, and then the relationship between nitrate (NO3)-nitrogen(N) concentration in plants and nitrate efflux from roots of two oilseed rape cultivars (Brassica napus L. cv. ‘Zhongyou 821’ (‘ZY821’) and “D89”) was compared on days 73, 74, and 75, respectively. Nitrate-N concentration in petioles of “ZY821” was significantly greater than in “D89”. Nitrate-N concentrations in the nutrient solution and petioles were high on day 73 and nitrate efflux from roots of “D89” was greater than from “ZY821”. On day 75, as nitrate-N concentrations in the nutrient solution declined, both the maximum cumulative efflux and efflux rate of “ZY821” was higher than “D89.” We hypothesized that “ZY821” could remobilize more nitrate-N from the petioles to meet its N needs. This would result in a decline in translocation of nitrate from roots to shoots and an increase in root cytoplasm nitrate concentrations and root efflux. |
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| Keywords: | nitrate-N concentration nitrate efflux petiole oilseed rape (Brassica napus L cv ) |
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