|Author:||Levi, A. ; Paterson, A. H. ; Barak, V. ; Yakir, D. ; Wang, B. H. ; Chee, P. W. ; Saranga, Y.|
|Book Group Author:||NA|
Quantitative trait loci (QTLs) for yield and drought related physiological traits, osmotic potential (OP), carbon isotope ratio (δ13C, an indicator of water use efficiency), and leaf chlorophyll content (Chl), were exchanged via marker-assisted selection (MAS) between elite cultivars of the two cotton species Gossypium barbadense cv. F-177 and G. hirsutum cv. Siv'on. The resulting near isogenic lines (NILs) were examined in two field trials, each with two irrigation regimes, in order to (1) evaluate the potential to improve cotton drought resistance by MAS and (2) test the role of physiological traits in plant productivity. NILs introgressed with QTLs for high yield rarely exhibited an advantage in yield relative to the recipient parent, whereas a considerable number of NILs exhibited the expected phenotype in terms of lower OP (5 out of 9), higher δ13C (4 out of 6) or high Chl (2 out of 3). Several NILs exhibited considerable modifications in non-targeted traits including leaf morphology, stomatal conductance and specific leaf weight (SLW). In G. barbadense genotypes, yield was correlated negatively with δ13C and OP and positively with stomatal conductance, SLW and Chl, whereas in G. hirsutum yield was negatively correlated with δ13C, SLW and Chl. This dissimilarity suggests that each of the respective species has evolved different mechanisms underlying plant productivity. We conclude that the improvement of drought related traits in cotton NILs may lead to improved drought resistance via MAS, but that conventional breeding may be necessary to combine the introduced QTL(s) with high yield potential.
|Pages:||179 - 195|
artificial selection, chlorophyll, cotton, cultivars,drought, drought resistance, evaluation, field experimentation, fieldtests, genetic markers, genotypes, irrigation, loci, osmosis,phenotypes, plant physiology, productivity, quantitative trait loci,quantitative traits, stomata, stomatal resistance, use efficiency, wateruse, water use efficiency, yields, Gossypium, Gossypium barbadense,Gossypium hirsutum, Malvaceae, Malvales, dicotyledons, angiosperms,Spermatophyta, plants, eukaryotes, Gossypium, cultivated varieties,drought tolerance, watering, Plant Production (FF100), Natural Disasters(PP800), Meteorology and Climate (PP500), Environmental Tolerance ofPlants (FF900), Plant Water Relations (FF062), Plant Breeding andGenetics (FF020), General Molecular Biology (ZZ360) (Discontinued March2000), Soil Water Management (Irrigation and Drainage) (JJ800) (RevisedJune 2002) [formerly Soil Water Management], Plant Morphology andStructure (FF030), Plant Physiology and Biochemis