Resistance of Alfalfa Varieties to the Potato Leafhopper: Seedling Survival and Field Damage After Infestation1
- James A. Webster,
- E. L. Sorensen and
- Reginald H. Painter2
Twenty-eight varieties and four experimental populations of Medicago sativa L., were tested in the seedling stage for resistance to the potato leafhopper, Empoasca fabae (Harris). The extremely winter-hardy varieties, ‘Rhizoma,’ ‘Rambler,’ ‘Teton,’ exhibited high seedling survival. In contrast, the nonhardy varieties, ‘African,’ ‘Hairy Peruvian,’ ‘Indian,’ ‘Moapa,’ and ‘Sonora,’ were highly susceptible. The reaction of the Flemish types, ‘Alfa,’ ‘DuPuits,’ and ‘Glacier,’ was similar and intermediate among varieties tested. The Turkistan-derived variety, ‘Lahontan,’ was highly susceptible. ‘Cherokee’ and the populations MSA-11 and MSB-11, which were developed for resistance to yellowing in the field from susceptible source material by recurrent selection, were resistant in greenhouse seedling tests. Experimental synthetics, KS 13 and N. S. 16, rated high for resistance in field and seedling tests.
Field yellowing scores were negatively correlated with seedlings survival in growth chamber tests (r= −0.607*). Repeatability of seedling resistance as determined by survival was demonstrated by a highly significant interannual correlation coefficient (+0.702***) for the unifoliolate growth stage.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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