Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 19, 1996
Publication Date: N/A
Technical Abstract: Multiple inoculations by inoculative Graminella nigrifrons were used to aid identification of tolerant germplasm and develop highly tolerant inbred lines. F2 populations were produced from crosses of tolerant inbred lines from the Virgin Island (VI), Dominican Republic (DR), and Compuesto Cuba 551 (CC) populations to a susceptible inbred, Va35. Seventy-six F2 individuals from each population were inoculated and evaluated for their response to MCDV. AUDPC scores (based on a 1-5 scale at 7, 11, 14, 18, and 21 days after the first of three inoculations) were used to evaluate tolerance and normality of the progeny distribution. An additional 240 F2 individuals of the VIxVa35 population were tested and formed the mapping population. The AUDPC scores of the tolerant parent, susceptible parent, and the F1 hybrid were 13, 56, and 42.5 respectively, and the F2 individuals scores ranged from 13 to 56. Analysis of the RFLP data of F2 individuals indicated that regions of chromosomes 3 and 10 had a log 10 of the odds ratio score of 9.7 and 4.2, respectively, and were responsible for 47 and 24%, respectively, of the phenotypic variation. These chromosomal regions also will be examined in the DRxVa35 and CCxVa35 F2 populations.