توارث مقاومت به گسترش فوزاريوم درون سنبله در گندم

Inheritance of resistance to fusarium within a spike of wheat

To study the inheritance of resistance to Fusarium graminearum in wheat the resistant cultivar Sumai 3 was crossed to the susceptible cultivar Falat. The parents and F1 and F2 progeny were evaluated in the greenhouse for resistance to the spread of fusarium within a spike. Inoculations were performed by injecting a droplet of inoculum into a floret at one third to fourth of main spike at the time of anthesis. Infected plants kept in greenhouse with high humidity and suitable temperature. Twenty one-days after inoculation the proportion of infected spikelets was recorded and percents was calculated from these proportions. Means and variances of the percents of infected spikelets were used to fit genetic model, estimate the number of genes and the heritability of resistance. The simple additive-dominance model explained the inheritance of resistance in the cross. Dominance and epistatic effects were not significant. Two to three resistance genes depending on the used formula was estimated. Broad-sense heritability was 0.86. The frequency distribution of the percent of infected spikelets were continous and within the limits of parents. The results indicates that it should be possible to select resistant individuals in F2 generation of this cross.