Abstract
Cassia is a diverse legume genus widespread in the (sub-)tropical zone of the world. Several studies have been done on this genus; however, significant changes have occurred at the taxonomic level over the years. This has led to inaccurate information about seed dormancy in Cassia since many species are no longer included in the genus. Thus, our work aims to investigate and update the information about the kind of dormancy that occurs in seeds of Cassia species and also look into two notorious species in this group (C. fistula and C. javanica) to compare myxospermous vs. non-myxospermous seeds regarding dormancy and germination traits. Seed dormancy reports were found for 53 Cassia species, and the only kind of seed dormancy found for these species was physical dormancy (PY). Non-dormancy was not found, and all seeds had a blockage to water uptake during the dormant state, that is, all have PY. Of these 53 species, only 18 are currently included in the genus Cassia. C. fistula and C. javanica have fully developed embryos, and dormancy is only conferred by the (water-impermeable) seed coat. The lens in the seed coat is the only structure that creates a water pathway to break PY in C. fistula. Myxospermous seeds came out of dormancy faster than non-myxospermous ones. PY seems to be the only kind of seed dormancy that has evolved in Cassia. The extent of this kind of dormancy in all subtribe Cassiinae is also discussed.
Highlights
Cassia is a diverse legume genus widespread in thetropical zone of the world
We addressed the following questions: (1) What is known about seed dormancy in Cassia? (2) How many of the six classes of seed dormancy [including non-dormancy] have been reported in Cassia species? (3) If seeds of C. fistula L. and C. javanica L. are dormant, are the embryo fully developed and/or the seed coat water impermeable at seed maturity and dispersal? (4) If they have physical dormancy (PY), what is(are) the water gap(s) in these seeds? (5) Since the genus Cassia has myxospermous seeds, could water-impermeable seeds take advantage of myxospermy?
Fifty-three Cassia species were found in the literature whose kind of seed dormancy was investigated
Summary
Cassia is a diverse legume genus widespread in the (sub-)tropical zone of the world. Several studies have been done on this genus; significant changes have occurred at the taxonomic level over the years. Fifty-three Cassia species were found in the literature whose kind of seed dormancy was investigated. The studies found in the literature showed that the investigated seeds had dormancy, and the treatments used to break PY (i.e., mechanical and acid scarification, immersion in hot water) were efficient in triggering high percentages of seed germination.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
