The inheritance of betalain pigmentation in Basella alba L.

Abstract

Basella alba is an underutilized leafy vegetable native to the Indian subcontinent. The therapeutic function associated with the consumption of this vegetable is well known, such as androgenic, anti-diabetic, anti-inflammatory and antioxidant activity. The plant's fruit and stem are blessed with natural betalain pigments. In the recent years, researchers have developed an increasing interest in the use of betalains as a natural food colorants. In this study, we report the natural variation between the B. alba genotypes for betalain pigmentation and examined its inheritance. To study its inheritance, a cross was made between two contrasting genotypes viz., ‘VRB–48–1′ (Basella alba var. alba) having green stem with snow-white flowers, and ‘VRB–43–1′ (Basella alba var. rubra) producing pigmented stem with red-violet flowers. The parental line ‘VRB–48–1′ had extremely low amounts of betalain pigments (4.26 mg/100 g FW) in the mature fruits, while the genotype ‘VRB–43–1′ had high betalain content (156.42 mg/100 g FW). Pigmented and non-pigmented (green) plants, obtained from crossing of these parental lines segregated in 3:1 in the F2 generation. Our results have shown that the single dominant gene governed purple pigmentation in B. alba. Further, we did not find any recombinant i.e. green plants with red-violet flower or pigmented plants with white flowers/intermediate shades suggesting role of major gene in controlling this trait. This simple inheritance will help in incorporation of this trait in mainstream breeding programme along with green yield. It was also evident from the results that the basal level of the betalain pigment component is always synthesized in the plants, beginning from start of life cycle to maturity. This is the first report of betalain pigment inheritance in B. alba.