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Genetic variation and heritability of forage yield in Mediterranean tall fescue
Author(s) -
Piano E.,
Annicchiarico P.,
Romani M.,
Pecetti L.
Publication year - 2007
Publication title -
plant breeding
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.583
H-Index - 71
eISSN - 1439-0523
pISSN - 0179-9541
DOI - 10.1111/j.1439-0523.2007.01416.x
Subject(s) - diallel cross , biology , heritability , additive genetic effects , agronomy , genetic gain , genetic variation , forage , mediterranean climate , genetic variability , germplasm , ecology , genetics , hybrid , genotype , gene
The genetic control of tall fescue forage yield has been poorly investigated. Full‐sib families from diallel crosses of Mediterranean germplasm were evaluated for forage yield over 34 months in a Mediterranean environment with severe drought stress (diallel 1, with 20 parents) and over 16 months under irrigation in a heated greenhouse simulating the Mediterranean temperature pattern (diallel 2, with 15 parents). Genetic parameters were estimated for fresh biomass in diallel 1 and dry‐matter yield in diallel 2. Additive genetic variance was always larger than non‐additive (dominance) variance. Narrow‐sense heritability was fairly high ( h 2 = 0.61) in diallel 1 and moderate ( h 2 = 0.45) in diallel 2. Predicted yield gains from one selection cycle were larger in the former diallel (23.9%) than in the latter (10.5%), suggesting that gains can be enhanced by selection under severe drought stress and over a time span sufficient to allow the variation in persistence to fully emerge. General combining ability effects of eight parents that were common to both diallel crosses were highly correlated ( r = 0.94) across the contrasting evaluation environments. The extent and consistency of additive genetic effects across environments suggest that rapid improvement of forage yield is possible.