Precision phenotyping of imidazolinone-induced chlorosis in sunflower.
Chlorosis level is a useful parameter to assess imidazolinone resistance in sunflower (Helianthus annuus L.). The aim of this study was to quantify chlorosis through two different methods in sunflower plantlets treated with imazapyr. The genotypes used in this study were two inbred lines reported to be different in their resistance to imidazolinones. Chlorosis was evaluated by spectrophotometrical quantification of photosynthetic leaf pigments and by a bioinformatics-based color analysis. A protocol for pigment extraction was presented which improved pigment stability. Chlorophyll amount decreased significantly when both genotypes were treated with 10 μM of imazapyr. Leaf color was characterized using Tomato Analyzer(®) color test software. A significant positive correlation between color reduction and chlorophyll concentration was found. It suggests that leaf color measurement could be an accurate method to estimate chlorosis and infer chlorophyll levels in sunflower plants. These results highlight a strong relationship between imidazolinone-induced chlorosis and variations in leaf color and in chlorophyll concentration. Both methods are quantitative, rapid, simple, and reproducible. Thus, they could be useful tools for phenotyping and screening large number of plants when breeding for imidazolinone resistance in this species.
Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario , CC 14, S2125 ZAA, Zavalla , Argentina ; CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas , Av. Rivadavia 1917-C.A.B.A ., Argentina.
Ana Claudia
AC
Ochogavía
Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario , CC 14, S2125 ZAA, Zavalla , Argentina ; CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas , Av. Rivadavia 1917-C.A.B.A ., Argentina.
Mercedes
M
Gil
Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario , CC 14, S2125 ZAA, Zavalla , Argentina ; CIUNR, Consejo de Investigaciones de la Universidad Nacional de Rosario , CC 14, S2125 ZAA, Zavalla , Argentina.
Liliana
L
Picardi
Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario , CC 14, S2125 ZAA, Zavalla , Argentina.
Graciela
G
Nestares
Helianthus annuus L.; carotenoids; chlorophylls; chlorosis; color analysis software; sunflower