ISSN:
1435-0653
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
indica and japonica cultivars of rice (Oryza sativa L.) subjected to a drying cycle in large pots in the greenhouse. The four methods were: (i) derivation of OA from regressions of leaf relative water content (RWC) on leaf osmotic potential (OP); (ii) estimation of OA from OP of stressed plants calculated to rehydrated state; (iii) estimation of OA from OP of stressed plants that have been rehydrated; and (iv) estimation (from data used in Method 1) of OA capacity by the sustained RWC at a given OP of -3.5 MPa. Method 1 was a priori considered as the best estimate. Under relatively mild atmospheric conditions and a slow development of water deficit (first experiment), mean OA over 12 cultivars was 0.89, 0.51, and 0.72 Mpa by Methods 1, 2, and 3, respectively. Mean RWC at -3.5 Mpa was 69.3%. Significant (P ≤ 0.05) variation in OA among cultivars was observed by all methods, up to a four-fold difference in OA among cultivars (0.35-1.51 Mpa) by Method 1. Simple correlation for OA across 12 cultivars with Method 1 was significantly higher for Method 3 (r = 0.76; P = 0.04) and Method 4 (r = 0.87; P 〈 0.01) than for Method 2 (r = 0.54; P = 0.07). OA by Method 4 was better correlated with Method 3 (r = 0.80; P 〈 0.01) than with Method 2 (r = 0.67; P = 0.02). The coefficient of variation (CV) as a measure of error was greater for Method 1 (47%) and Method 2 (31%) than for Method 3 (21%) or 4 (24%). Both Methods 2 and 3 were less demanding on labor and plant materials than Methods 1 and 4. The results support the use of Method 3 (the "rehydration method") as a faster and an economical replacement for Method 1.
Type of Medium:
Electronic Resource
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