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Mode of Gene Action for Resistance in Maize to Maize Streak Virus
Author(s) -
Kim SoonKwon,
Efron Y.,
Fajemisin J. M.,
Buddenhagen I. W.
Publication year - 1989
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/cropsci1989.0011183x002900040009x
Subject(s) - biology , backcrossing , streak , leaf spot , agronomy , infestation , hybrid , hectare , veterinary medicine , horticulture , gene , agriculture , genetics , medicine , physics , optics , ecology
Maize streak virus (MSV) transmitted by Cicadulina leafhoppers causes severe yield loss of maize ( Zea mays L.) in Africa. This paper summarizes our studies on gene action for resistance to MSV using generation mean analysis. Crosses were made between a resistant inbred (IB32) and four susceptible inbreds (BI4, B68, B73, and Moi7). A total of II 255 plants from the four sets of biparentul crosses, their F 2 , backcross, and F3 progenies were grown in four experiments under severe artifically induced MSV epiphytotics at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Severity of streak symptoms on test plants was classified on a five‐point scale based on the amount of streaking of leaves. Under severe artificial infestation inside a screenhouse, average ratings of resistant and susceptible parents were 1.3 and 5.0, respectively. The average F 1 rating was 3.13, which was close to the mean midparent value (3.15). The average F 2 rating was 2.83, which was 0.3 units more resistant than the F 1 value. The average rating of four F 1 crosses in the field was 2.22, 0.81 units more resistant than the mean midparental value (3.03). Average rating of the F 2 populations was 2.22, which was similar to that of the F 1 (2.27). Backcross ratings were close to mean of the F 1 and recurrent parent. Individual F 3 plants derived from same rating of F 2 plants showed considerable variation in ratings. Resistance to MSV from IB32 appeared to be inherited quantitatively with relatively small numbers of genes involved. The symptoms of MSV varied with the genetic background of the susceptible parent. Simple recurrent selection or modified backcross breeding methods could be used to breed for MSV resistance in Africa.