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Genetic Control of Long Daylength Response in Soybean
Author(s) -
Saindon G.,
Voldeng H. D.,
Beversdorf W. D.,
Buzzell R. I.
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/cropsci1989.0011183x002900060021x
Subject(s) - biology , epistasis , allele , genotype , cultivar , heritability , horticulture , dominance (genetics) , genetics , gene
An understanding of the genetics of the long daylength response of soybean [ Glycine max (L.) Merrill] would facilitate the development of cultivars adapted to the long days of the northernmost growing areas of North America and Europe. The objective of this study was to determine the genetic control of soybean response to extension of the natural daylength to 20h using incandescent lamps. Three pairs of near‐isogenic lines (NIL) plus a long daylength insensitive check were grown outdoors and rated visually for response to incandescent long day (ILD). The same entries were further grown indoors and rated for response to extension of the natural daylength to 20h using cool white fluorescent lamps (FLD). Based on these results, entries were classified for alleles at the E 3 and E 4 maturity loci. Check OX619 and ILD‐insensitive NILs X2398, X2403, and X2396 were classified genotypically as e 3 e 3 e 4 e 4 . The respective recurrent parents were all ILD‐sensitive and were classified: Evans‐ e 3 and Harosoy‐ e 3 as e 3 e 3 E 4 E 4 and ‘Maple Arrow’ as E 3 E 3 e 4 e 4 . Analyses of F 2 and F 2:3 populations from five crosses revealed that only the e 3 e 3 e 4 e 4 genotype is ILD‐insensitive. Consequently, a model of two ( E 3 and E 4 ), each with two alleles, each with dominance, plus epistasis of E 3 on e 4 > is proposed to explain the ILD‐insensitivity. It was concluded that E 3 is the major locus conferring long daylength insensitivity in soybean, but both E 3 and E 4 have to be considered when breeding for insensitivity to long daylength using ILD.