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Low genetic variability of Striga gesnerioides populations parasitic on cowpea might be explained by a recent origin
Author(s) -
DUBE MP,
BELZILE F J
Publication year - 2010
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.2010.00804.x
Subject(s) - striga , biology , amplified fragment length polymorphism , scrophulariaceae , obligate , genetic variability , population , cultivar , parasitic plant , genetic variation , botany , agronomy , genetic diversity , host (biology) , genotype , genetics , gene , germination , demography , sociology
D ube M ‐ P & B elzile FJ (2010). Low genetic variability of Striga gesnerioides populations parasitic on cowpea might be explained by a recent origin. Weed Research 50 , 493–502. Summary Striga gesnerioides is an obligate root hemiparasitic plant that causes considerable yield losses to cowpea, an important crop legume of Sub‐Saharan Africa. The use of resistant cultivars is the easiest and most effective method to control the parasite. Several cowpea cultivars exhibiting resistance have been identified during the last decades. However, most resistant cultivars show a differential response when grown in different countries across West Africa, suggesting that there are different races of S. gesnerioides . In this study, we investigated the genetic variability within and between 43 populations of five of the previously recognised races of the parasite present in West Africa. Amplified fragment length polymorphism (AFLP) markers were used on up to 10 individuals from each population. These markers showed almost no genetic variability within populations. The variability between the populations was also extremely low and did not allow discrimination of the five races. There was a certain geographical structure, but no ‘racial’ clustering could be seen. Even AFLP markers previously reported to be race‐specific on another set of Striga populations proved unable to discriminate between races in this collection of populations. Possible causes of the low level of genetic variability include the hypothesis that this strain has only quite recently arisen. Such a low level of variability and the absence of specific markers for the virulence will have consequences on the evolution of the parasite and on the development of adequate control methods.