Dormancy imposed by a tough seed coat in Malvella sherardiana (Malvaceae), a highly threatened species of Spain. Issue 3 (2nd July 2016)

• Record Type: Journal Article
• Authors: Veiga-Barbosa, L.; Ruiz, C.; Correa, E. C.; Pérez-García, F.
• Is Part Of: Botany letters. Volume 163:Issue 3(2016)
• Page Start: 321
• Page End: 327
• Publication Date: 2016-07-02
• Subjects: Gibberellic acid -- Malvaceae -- seed dormancy -- seed germination -- seed scarification -- threatened species; Botany -- Periodicals; Botany; Botany; Electronic journals; Periodicals; Periodical; 580
• DOI: 10.1080/23818107.2016.1181004
• Languages: English
• ISSNs: 2381-8107

Abstract

Abstract: Malvella sherardiana (L.) Jaub & Spach (Malvaceae) is a perennial herbaceous plant listed as Vulnerable in the Red List of threatened plant species for Spain. The germination characteristics under controlled conditions of light and temperature of M. sherardiana seeds were studied. Mechanical scarification, cold stratification, liquid nitrogen, freezing, hot water, dry heat, sulphuric acid, soaking in distilled water and soaking in gibberellic acid were used as pre-sowing treatments applied for enhancing germination. The untreated seeds showed a high dormancy at all temperature regimens tested and sulphuric acid scarification drastically improved final germination percentage and germination rate. Germination of seeds soaked in concentrated sulphuric acid arithmetically increased as soaking time increased (from 5 min to 3 h), but seeds soaked in acid for more than 4 h failed to germinate. The application of a gibberellic acid solution (1000 mg l −1 ) increased the germination percentages for all tested soaking times in sulphuric acid. However, it was only significantly effective for the soaking time of 3 h. The other pre-sowing treatments resulted in some germination, but none resulted in greater germination than sulphuric acid. As embryos are fully developed and the seed coat is water permeable, we conclude that M. sherardiana seeds present physiological dormancy. The main conclusion of the study is that dormancy of M. sherardiana seeds is attributed to mechanical restriction of the embryo caused by the tough seed coat. This is the first report on germination requirements of the Malvella genus.