Wednesday, 8 October 2008
George R. Brown Convention Center, Exhibit Hall E
Buffalograsses, Buchloë dactyloides (Nutt.) Engelm., were evaluated under greenhouse culture for resistance to the Rhodesgrass mealybug, Antoninis graminis Maskel. Among 76 entries, four genotypes, TTU-58B, TTU-86A, TTU-94A and TTU-223A, had mean infestations ≤ 0.22 mealybugs per 6.4 cm diam plant. TTU-86A and TTU-94A are tetraploids while TTU-58B and TTU-223A are hexaploids. An additional five hexaploid genotypes were infested with ≤ 1 mealybug per plant. However, FH-5, a diploid, had a moderate infestation rate but exhibited the lowest damage ratting of 1.78 (scale of 1 to 5, where 1 = little or no damage) among all the test entries. Two genotypes, TTU-35 and TTU-115 were the most susceptible entries with the highest infestation rate of > 21 Rhodesgrass mealybugs per plant; these entries were also hexaploids. Several other diploid and tetraploid genotypes were also evaluated, but did not provide resistance.