TITLE:
Germination Biology and Occurrence of Polyembryony in Two Forms of Cats Claw Creeper Vine, Dolichandra unguis-cati (Bignoniaceae): Implications for Its Invasiveness and Management
AUTHORS:
Joshua C. Buru, Kunjithapatham Dhileepan, Olusegun O. Osunkoya, Tanya Scharaschkin
KEYWORDS:
Macfadyena unguis-cati, Plant Sexual Reproduction, Plant Invasion, Propagule Pressure, Seed Ecology, Woody Vine
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.3,
March
29,
2016
ABSTRACT: Cat’s claw creeper
vine, Dolichandra unguis-cati (L.)
Lohmann (syn. Macfadyena unguis-cati (L.) Gentry), is a major environmental weed in Australia. Two forms (“long” and
“short” pod) of the weed occur in Australia. This investigation aimed to
evaluate and compare germination behavior and occurrence of polyembryony
(production of multiple seedlings from a single seed) in the two forms of the
weed. Seeds were germinated in growth chambers set to 10/20°C, 15/25°C,
20/30°C, 30/45°C and 25°C, representing ambient
temperature conditions of the region. Germination and polyembryony were
monitored over a period of 12 weeks. For all the treatments in this study,
seeds from the short pod form exhibited significantly higher germination rates
and higher occurrence of polyembryony than those from the long pod form. Seeds
from the long pod form did not germinate at the lowest temperature of 10/20°C;
in contrast, those of the short pod form germinated under this condition,
albeit at a lower rate. Results from this study could explain why the short pod
form of D. unguis-cati is the more
widely distributed form in Australia, while the long pod form is confined to a
few localities. The results have implication in predicting future ranges of
both forms of the invasive D. unguis-cati,
as well as inform management decisions for control of the weed.