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The Inheritance of Fusarium Wilt Resistance in Flax 1
Author(s) -
Burnham Charles R.
Publication year - 1932
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1932.00021962002400090008x
Subject(s) - fusarium wilt , inheritance (genetic algorithm) , resistance (ecology) , agricultural experiment station , citation , library science , biology , horticulture , genetics , agriculture , agronomy , computer science , fusarium oxysporum , ecology , gene
The disease caused, by Fusarium lini Boll. is characterized by a sudden wilting of the flax plant at any .st.age from the seedling to maturity. In certain cases, plants may show yellowed or wilted leaves on one side of the stem only but extending from crown to tip, or the main stem may die and new, apparently healthy branches appear at the crown. The anaount of wilt in susceptible strains has been shown by Tisdale (6) 3 and by Jones and Ti,sdale (2) to vary with the temperature. Between temperatures of 20° and 34° C, the amount is very high, but below 16" C and above 36o C, very little appears. The optimum for the wilt is at 24° to 28" C. Certain variations in the results obtained by Tisdale (5) seemed explainable on the basis of genetic impurity in the parent stocks. In an experiment by the writer in which blue-flowered and whiteflowered strains of flax were planted in alternate rows IO inches apart, 1.12% of cross-pollinated, i.e., blue-flowered offspring, were observed in a total of I,I6I plants from the white-flowered individuals. All but one were tested and all these proved to be crosses. The observed number of off-types varied from none to as high as 4.29% on different plant,s. In the present work, in order to insure homozygosity, at leas.t three generations of selfing preceded the cros.sing. Since the environment plays such an important r61e in the expression of resistance and susceptibility, the F2 was classified on the basi,s of an F~ test. Since strains have been obtained which breed true for intermediate percentages of wilt, however, one cannot decide from an F~ progeny test alone whether or not the observed percentage of wilting is due to segregation. At the present time it seems that nothing short of extensive F~ tests can settle this point and provide a basis for determining the number of factors concerned in a particular cross.