Inheritance of resistance to crown rust and certain morphological traits in crosses involving Avena sterilis L. and methods of breaking seed dormancy in oats

Abstract

Six strains of A. sterilis introduced form Israel as breeding sources of crown rust of oats were crossed with a very susceptible variety Frazier. The number of genes conditioning resistance in the 6 strains was determined from studies of the F₁, F₂, and F₃ populations. To determine if any genes conditioning crown rust in the 6 strains are common, all possible crosses were made among the strains, excluding reciprocals. Young seedlings, at the 2-leaf state, were inoculated with pure cultures of crown rust race 326. The number of genes conditioning crown rust resistance was determined from the type of segregation exhibited by each cross. Observed ratios were compared with expected genetic ratios by use of chi-square test for goodness of fit. When the F₂ and F₃ populations of crosses among A. sterilis segregated, they were considered to have different genes for resistance. P.I. 287211, C.I. 8295, P.I. 295919 and P.I. 296244 appeared to each have a single dominant gene and P.I. 29265 abd P.I. 296266 appeared to have 2 dominant genes for rust reaction to crown rust race 326. C.I. 8295 had a partially dominant gene for resistance. P.I. 287211 appeared to have a gene for resistance which as common with that found in C.I. 8295. ...