Screening finger millet (Eleusine coracana L. Gaertn) genotypes for pre and postattachment resistance to witchweed (Striga asiatica L. Kuntze) infection under controlled environments

Abstract

Witchweed (Striga asiatica L. Kuntze) is an obligate hemi-parasitic weed that causes cereal
yield loss of 20-100% depending on its seed bank size and susceptibility of host cereal. Climate
change linked reduction of maize (Zea maize L.) productivity  created the need to identify
small grains genotypes that can withstand the adverse effects of climate change in S. asiatica
endemic areas. Hence, this study aimed to determine the resistance of finger millet genotypes
to S. asiatica infection. 3 genotypes that were bred at the International Crops Research
Institute for the Semi-Arid Tropics (ICRISAT) were evaluated under laboratory and glasshouse
conditions at the University of Zimbabwe during the 2018/2019 summer cropping season.
In the laboratory assay, three finger millet genotypes (KNE624, KNE814 and SDMF1702)
were screened for pre-attachment resistance using the Agar-gel technique. The experiment
was laid out as a Completely Randomized Design (CRD) with ten replications. The measured
parameters were S. asiatica germination percentage and furthest germination distance. In the
pot study, a 3 x 2 factorial experiment was set up and arranged in a Randomised Complete
Block Design (RCBD) with 6 replications The measured parameters included plant height,
Striga emergence, haustorial attachments, chlorophyll content, plant tissue biomass and grain
yield of finger millet. The genotype SDMF1702 had significantly (p<0.05) lower Striga
germination percentage and furthest germination distance than the other genotypes. There was
a significant (p<0.05) genotype x Striga interaction on the plant height, chlorophyll content,
stem biomass, root: shoot ratio &  total above ground biomass where SDMF1702 showed
tolerance. 
genotype SDMF1702