Table 1.
Criteria used for categorizing the cork oak acorn into different developmental stages. Representation of each stage in the normalized (N) and non-normalized (nN) cDNA libraries. Embryo tissues isolated from acorns belonging to stages S3-S5 and S8 were classified as EM3-EM5 and EM8
| Developmental stage | Max Ø with cupule (mm) | Max Ø without cupule (mm) | Isolation of embryos | Other observations; library type |
|---|---|---|---|---|
| S1 | 2 - 3 | nd | no | no endosperm visible; N and nN |
| S2 | 3 - 5 | nd | no | multiple fertilized ovules, some aborted; N and nN |
| S3 | 5 - 8 | nd | yes (EM3) | dominant embryo; N and nN |
| S4 | 8 - 12 | nd | yes (EM4) | acorn completely covered by the cupule; N and nN |
| S5 | 12 - 17 | 7 - 11 | yes (EM5) | acorn already visible out of the cupule; N and nN |
| S6 | 17 - 20 | 11 - 16 | no | ~1/2 of the acorn out of the cupule |
| S7 | >20 | >16 | no | Green acorn mostly out of the cupule; N |
| S8 | >20 | >16 | yes (EM8) | Brown acorn; N and nN |
nd: not determined