ORGANIC ACID EXUDATION UNDER PHOSPHORUS STRESS AND ITS RELATIONSHIP WITH PHOSPHORUS UPTAKE EFFICIENCY IN MUNGBEAN (Vigna radiata (L.) Wilczek)
KrishiKosh
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Title |
ORGANIC ACID EXUDATION UNDER PHOSPHORUS STRESS AND ITS RELATIONSHIP WITH PHOSPHORUS UPTAKE EFFICIENCY IN MUNGBEAN (Vigna radiata (L.) Wilczek)
M Sc |
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Creator |
NAVAL KISHORA
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Contributor |
Renu Pandey
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Subject |
sowing, soaking, acidity, inorganic acids, sulphur, germinability, irrigation, application methods, seed treatment, solutes
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Description |
T-8323
An attempt was made to study the organic acid exudation and its relationship with phosphorus (P) uptake efficiency in mungbean genotypes grown under low (2 µM) and sufficient (100 µM) P conditions. Initially 60 genotypes were screened on the basis of total plant dry weight and 44 were selected to screen them for total root exudation. All the 44 genotypes grown at low and sufficient P were labeled with 14C and total exudation was assessed by counting 14C. The genotypes were categorized into four groups based on relative total root exudation and biomass at low and sufficient P as, a) efficient and responsive (PDM-139) (b) efficient and nonresponsive (SM-149, SM-9-206) (c) non-efficient and responsive (SM-9-117, SM- 262) and, (d) non-efficient and non-responsive (SM-9-202, SM-9-157). These 7 genotypes were used to measure root exudation and internal concentration of organic acids (OA). The OA released in the rhizosphere under low P were mainly oxalic and citric acids while those in root tissues were oxalic, succinic, lactic and maleic acids. Synthesis of oxalic, succinic and lactic acids were higher under low P in root tissues but they were not released into the rhizosphere. Among the morpho-physiological parameters, the chl a, total chlorophyll and starch concentration were higher in low P compared to sufficient P. Total leaf area per plant was significantly higher at sufficient P in all the genotypes while specific leaf weight did not show any specific trend between the different categories. Among the root morphological parameters, no specific pattern was observed for root length, number of lateral roots and lateral root density between the categories of genotypes while root surface area increased at low P and the percentage of increase was higher in ENR genotypes. The P utilization efficiency was higher in low P plants and the increase was maximum in genotypes belonging to NER, ENR and ER category. Thus, this study shows that exudation of organic acid in the rhizosphere is an important phenomena which in involved in solubilizing the fixed P. The genotypes belonging to NER, ENR and ER released higher amount of OA resulting in maximum PUE. |
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Date |
2016-10-22T09:42:09Z
2016-10-22T09:42:09Z 2010 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/81336
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Format |
application/pdf
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Publisher |
IARI, DIVISION OF PLANT PHYSIOLOGY
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