| Abstract Detail
Recent Topics Posters Ogunwenmo, K. Olusola [1], Oyelana, Olatunji [1]. Ipomoea aquatica Forssk. (Convolvulaceae) biotypes exhibit ecobiogeographic and cytomorphological variations in Nigeria. Field and laboratory studies of Ipomoea aquatica were carried out to determine the basis and nature of the species variability and spread. Species distribution revealed three biotypes: perennial, pantropical, established i. widely distributed forest-savanna, ii. restricted savanna and iii. an annual, sporadic, forest ecotype. The seeds of the latter germinated in soil from six to eight weeks with smaller cotyledon lobes (30 - 33 x 4 - 5 mm). The other two ecotypes germinated within two weeks sometimes up to six weeks in some populations, with slightly lager cotyledons (30 - 33 x 5 - 6.5 mm). They were distinguished into narrow (4.2 - 6.4 x 0.5 - 2.6 cm) and broad (5.5 -14 x 3.7 - 10.6 cm) leaf morphotypes with variable leaf shapes (lanceolate, hastiform, sagittiform or triangular). The established wetland perennials reproduced largely by vegetative means, one to three flowered with fewer (14 %) but larger fruits (7 - 13 x 5 - 16 mm) and seeds (4 - 8 x 4 - 6 mm) modified for water dispersal. The sporadic annuals reproduced by seeds, four to ten flowered with many (86 %) but smaller fruits (5.5 - 8.5 x 4.5 - 8 (10) mm) and hard-coated seeds (3.5 – 5.5 x 3.5 – 5 mm) adapted to dry land conditions. The diploid chromosome number (2n) was 30 and 28 for the perennial and annual biotypes respectively. The study showed that the biotypes resulted from adaptation to their environment and loss of a chromosome complement.
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1 - Babcock University, Ilishan-Remo, Dept. of Basic & Applied Sciences, PMB 21244, Ikeja, Lagos, Lagos, 100-001, Nigeria
Keywords:
Ipomoea aquatica
Convolvulaceae
Nigeria
ecotype
morphotype
chromosome number.
Presentation Type: Recent Topics Poster
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P79019
Abstract ID:2627 |
