Genetics of resistance toPhytophthora capsiciin the Mexican pepper‘Line 291

Publisher Website
Google Scholar
Abstract
In order to establish a genetic model of the resistance toPhytophthora cupsiciinCapsicum annuumgenotype‘Line 29′, three experiments were conducted which included, as well as‘Line 29′, the susceptible genotype‘Morron INIA 224’and several of its F1, F2, F3and backcrosses. Plants with 4–6 leaves were inoculated by irrigating the culture substrate with a zoospore suspension of isolate B 1. The F2test was applied to the segregating generations to test whether there were one, two, three or four genes involved in the resistance. Additivity and equal weight of all the genes in the final effect were assumed. The hypothesis that best explained the results obtained was the one that assumed three genes in‘Line 29′; at least four alleles had to be present in any genotype for it to behave as resistant. The possible influence of isolate aggressiveness and inoculation method on the results is discussed.