Manifestation of the Maternal Effect in Inheritance of Leaf Colour in Safflower

Abstract

Safflower is a representative of Asteraceae and is one of the most ancient crops cultivated by man. Its center of origin is the Mediterranean. Safflower is one of minor crops: its sown area is limited and it is used by a small number of countries, including Ukraine. This is a rough herbaceous plant, adapted to the hot arid climate, the habitat of safflower is confined to the steppes and semi-deserts. Today it is used mainly as an oilseed crop. Golkar et al. studied the level of chlorophyll in safflower leaves. The level of chlorophyll a, b and a + b in safflower in hybrids and parental lines was evaluated. As a result, it was found that in most cases hybrid plants have levels of chlorophyll intermediate in relation to the parental lines. Chlorophyll a and b have different absorption maxima. The maxima of the first are in the ranges 420-440 and 650-670 nm, the second - 450-470 and 630-650 nm. For this reason, chlorophyll a has a bluish tint and chlorophyll b has a yellowish tint. The aim of this work was to clarify the nature of the inheritance of leaf color in safflower. The colour of leaves in safflower was studied. The work was provided on the material of the Institute of oilseed crops of National academy of afrarian sciences of Ukraine collection. The parent samples had 3 phenotypes: a medium-tone blue-green leaf, a light green leaf, and a light yellow-green leaf. Leaf color was evaluated visually and using the Adobe Photoshop CS3 computer program in Lab and RGB modes. In Lab mode, the assessment was performed in the Lightness channel to determine the average or light tone of the sheet. While breeding samples with different leaf color the results of direct and reciprocal crossing differed, the F1 hybrids had leaf colour matched the maternal plant. In the second generation segregation was observed. Basing on the received data, we draw a conclusion that 3 nuclear genes with cytoplasmic genes determine inheritance of leaf colour. We propose that the nuclear genes be designated Gra, Grb, Grc as “green”. The interaction of these genes with cytoplasmic genes gives a light, medium, and dark leaf tone. In the cytoplasm, we assume two possible genotypes. Depending on them, the type of cytoplasm can be normal or light. Phenotypic manifestations of some gene combinations (gra gra Grb-Grc- — medim leaf tone; Gra-grb grb Grc-, Gra-grb grb grc grc, gra gra Grb-grc grc — light leaf tone) do not depend on the type of cytoplasm. In other cases a maternal effect is observed. In the combination of genes Gra-Grb-Grc- the light type of cytoplasm brightens the medium tone of the leaf to light, and in the combination gra gra gra grb grb Grc- — dark to medium, which determines the existence of different variants of segregation according to the phenotype with the same genotype. So we conclude that leaf color is inherited by three nuclear genes Gra, Grb, Grf-. Additionally, the color of the leaf is affected by cytoplasm. Light cytoplasm can brighten the leaf tone compared to the mediun for the same genotype. There are genotypes whose leaf tone does not depend on the type of cytoplasm.