Open AccessTechniques for breaking seed dormancy of rainforest species from genus Acronychia
Author(s) -
Ganesha S. Liyanage,
Catherine A. Offord,
Karen D. Sommerville
Publication year - 2020
Publication title -
seed science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.246
H-Index - 42
eISSN - 1819-5717
pISSN - 0251-0952
DOI - 10.15258/sst.2020.48.2.03
Subject(s) - scarification , biology , radicle , germination , dormancy , seed dormancy , botany , horticulture
We tested for dormancy in three species of Acronychia (Rutaceae) occurring in the rainforest in eastern Australia, A. imperforata , A. laevis and A. oblongifolia , by incubating fresh intact seeds on 0.8% water agar for one month at 25/10°C. Four different techniques were then tested for their effect on dormancy: (i) incubation of intact seeds on agar incorporating gibberellic acid (GA 3 ); (ii) seed coat removal (decoating); (iii) scarification near the radicle emergence point (scarification-emergence point); and (iv) scarification opposite the radicle emergence point (scarification-back). Imbibition tests were performed to determine whether dormancy was due to an impermeable seed coat. Germination differed among treatments, but all three species showed a similar pattern. Intact seeds showed < 6% germination after one month indicating the presence of dormancy. Highest germination (> 65%) was observed following scarification-emergence point treatment. Seed coat removal also resulted in increased germination (40-47%), in comparison with intact seeds, but GA 3 and scarification-back treatments did not (< 12%). Though the seedcoats of all species were permeable, increased germination responses to decoating and scarification-emergence point treatments suggest scarification is required to clear the radicle emergence point. This may be a useful dormancy-breaking technique for Acronychia spp. and may be suitable for related Rutaceae species.