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Inheritance of Phytophthora Root Rot Resistance in Alfalfa 1
Author(s) -
Lu Nancy ShyhJane,
Barnes D. K.,
Frosheiser F. I.
Publication year - 1973
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1973.0011183x001300060037x
Subject(s) - biology , diallel cross , root rot , phytophthora , resistance (ecology) , botany , horticulture , genetics , agronomy , hybrid
The inheritance of Phytophthora root rot resistance was determined in alfalfa ( Medicago sativa L.) for five clones from the variety ‘Lahontan’ and six clones from ‘Vernal’ and Vernal‐type varieties. A heterozygote‐diallel crossing scheme was used as the basis for genetic analysis. Parent clones were selfed, intercrossed, and testcrossed to two susceptible clones. Degree of resistance was determined by type of root‐rot lesion. Susceptibility appeared to be conditioned by one tetrasomic gene, Pm , with incomplete dominance. The nulliplex condition produced highly resistant plants. The simplex condition produced a moderate degree of resistance. Duplex, triplex, and quadruplex plants were increasingly more susceptible. Resistance in the Lanhontan and Vernal‐type varieties appeared to be controlled by the same gene.