Table 2.
Effect of different exogenous auxins (IAA, IBA and NAA) on hairy roots of C. arabica. Each value represents the average ± s.e. of five replicates
| Auxin type | Concentration (μm) | Branching (number of lateral roots cm–1) | Growth rate (mm d–1) | Vitrification index (0–5)* |
|---|---|---|---|---|
| No auxin (control) | 0 | 2·3 ± 1·0b | 0·05 ± 0·06d | 0·0c |
| IAA | 0·125 | 8·8 ± 4·2ab | 0·48 ± 0·11abc | 3·0 ± 0·5a |
| 0·25 | 5·8 ± 2·0b | 0·50 ± 0·29abc | 3·2 ± 0·6a | |
| 0·5 | 9·2 ± 3·8ab | 0·21 ± 0·11bcd | 3·6 ± 0·8ab | |
| 5 | 14·8 ± 2·1ab | 0·14 ± 0·07cd | 4·2 ± 0·5a | |
| IBA | 0·125 | 5·0 ± 1·8b | 0·44 ± 0·15abcd | 0·2 ± 0·3c |
| 0·25 | 11·3 ± 3·1ab | 0·60 ± 0·1ab | 1·2 ± 0·6bc | |
| 0·5 | 18·5 ± 5·0a | 0·68 ± 0·08a | 3·2 ± 0·6ab | |
| 5 | 0·6 ± 0·1c | 0·0d | 5·0 ± 0·0a | |
| NAA | 0·125 | 4·8 ± 1·2b | 0·28 ± 0·11abcd | 2·4 ± 0·9abc |
| 0·25 | 19·0 ± 6·4a | 0·55 ± 0·19abc | 4·0 ± 0·4a | |
| 0·5 | 11·4 ± 5·8ab | 0·26 ± 0·15abcd | 4·6 ± 0·6a | |
| 5 | 0·0c | 0·0d | 5·0 ± 0·0a |
* Index using a scale where 0 = none, and 5 = totally vitrified.
Values with different letters are significantly different at P < 0·001 according to Duncan's test.