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Heterosis and Mixing Effects in Winter Oilseed Rape
Author(s) -
Léon J.
Publication year - 1991
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/cropsci1991.0011183x003100020009x
Subject(s) - cultivar , heterosis , biology , diallel cross , brassica , rapeseed , yield (engineering) , homogeneous , agronomy , gene–environment interaction , loss of heterozygosity , horticulture , hybrid , botany , mathematics , allele , biochemistry , materials science , combinatorics , gene , genotype , metallurgy
Open‐pollinated synthetics and lineal cultivar structures of rapeseed ( Brassica napus L. var. napus ) are used for commercial production. All are different in degree of heterozygosity and heterogeneity. This study was conducted to determine heterosis and mixing effects, and their interactions on yield and yield stability. From four randomly‐chosen winter oilseed rape cultivars the F 1 , F 2 , two‐component cultivar mixtures and Syn 1 were produced using a diallel design. Furthermore, three two‐component F 1 mixtures were produced. The cultivars, cultivar mixtures, F 1 's and Syn 1 's were tested at four locations in northern Germany in 1982–1983 and 1983–1984. The F 2 's and F 1 mixtures were tested in 1983–1984. Mixtures of cultivars outyielded cultivars by 6%. The F 1 's outyielded cultivars (by 15%), cultivar mixtures (by 8%), and Syn, (by 6%). The F 1 mixtures outyielded F 1 's in pure stands by 6%. The F 2 's surpassed cultivars by 4%, but yielded less than expected based on the parental and F 1 results. The stability parameter ecovalence revealed a positive effect of increasing heterozygosity and heterogeneity on yield stability. The effect of heterogeneity on yield stability was greater than the effect of heterozygosity. The F 1 mixtures showed high yield and high yield stability. The results suggest that heterogeneous hybrid structures of winter rape may be superior to homogeneous hybrid structures.