Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Entire DC Network
A Study Of Striga Chromosome Numbers With A Comparison To Those Of Some Genera In The Rhinathoideae And The Orobanchaceae, Cynthia White
A Study Of Striga Chromosome Numbers With A Comparison To Those Of Some Genera In The Rhinathoideae And The Orobanchaceae, Cynthia White
Biological Sciences Theses & Dissertations
New chromosome counts are given for nine species of Striga including S. elegans (n=18), S. asiatica (n=19), S. forbesii (n=22), S. densiflora (n=26), S. aspera (n=27), S. passargei (n=28), and S. hermonthica (n=30). Previous counts reported for S. gesnerioides (n=20) and S. angustifolia (n=20) are verified. Evidence from the base number (x=10), chromosome counts, and differences in chromosome size (bimodality) suggests that the genus is an allotriploid with a descending aneuploid series. Genomic change appears to occur by different mechanisms in the Rhinanthoideae; some genera display a euploid series, others show aneuploidy, and some are very stable. Genera examined …
Studies On The Giant Mealie Witchweed, Striga Forbesii Benth., In Zimbabwe, David Allen Knepper
Studies On The Giant Mealie Witchweed, Striga Forbesii Benth., In Zimbabwe, David Allen Knepper
Biological Sciences Theses & Dissertations
Of the seven species of Striga found in Zimbabwe, S. forbesii Benth. is currently the most destructive in terms of crop damage. Owing to its limited occurrence worldwide as a pest of crops, relatively little work has been done on this species.
Striga forbesii has been found to be a consistent problem on both maize and sorghum in the Hunter's Road District of KweKwe, Zimbabwe. Results of a pot study and field observations, indicate S. forbesii can successfully parasitize Urochloa panicoides Beauv., Sorghum arundinaceum (Desv.) Stapf, and Rottboellia cochinchinensis (L.) L.f., all of which are widespread weeds of arable land. …
The Pollen Exostructure Of Striga (Scrophulariaceae), Mark A. Deleonardis
The Pollen Exostructure Of Striga (Scrophulariaceae), Mark A. Deleonardis
Biological Sciences Theses & Dissertations
In this survey, the pollen exostructure of 13 Striga species was examined using light microscopy and scanning electron microscopy. Two of the 13 species were also observed by transmission electron microscopy to assess major differences in exine composition. Striga pollen is consistently spherical to oblate, isopolar, tectate, and three or four colpate. Sculpturing may be psilate, psilate-perforate, finely rugulate, or coarsely rugulate. The equatorial width of the species surveyed ranged from 15 to 30 micrometers. It is concluded that variation in Striga pollen sculpturing, aperture structure, and size support the current taxonomy of the genus.