Application analysis of novel purple sweet corn inbred line development for hybrid nutrient-rich fruit corn breeding

【Objective】To combine super sweet corn phenotype and anthocyanins pigment to breed nutrient-rich hybrid fruit corn for Vietnam market.【Method】Sweet purple corn inbred lines were bred from backcross between purple waxy corn and white sweet corn from the spring of 2015. Twenty lines in the BC₂F₁ generation were bred via morphological markers selection(maize with dark purple and shrunken kernel). From the Spring, 2016 to Autumn-Winter, 2019, after evaluation, 80 inbred lines were obtained through selfing over five generations. Twenty elite inbred lines were selected and tested in Spring of 2020 under the Line×Tester mating design to produce 40 topcross hybrids. The field experiment laid out in RCBD with 3 replicates in Autumn-Winter, 2020, Hanoi, Vietnam.【Result】The result in the Autumn-Winter, 2020 season showed that 6 hybrids viz., TH08, TH17, TH18, TH27, TH31, and TH35 had high yield, with a range of 13.4-14.4 t/ha, without significant difference(P>0.05) found in the yield between these hybrids and check variety SW1011, suggesting the commercial potential of these sweet purple corn varieties. Nine lines, UV03, UV07, UV08, UV10, UV12, UV16, UV18, UV42 and UV71 with Brix sweetness index(BRIX) >16%, pericarp thickness(PER) <60.0 μm, anthocyanin content(AN) >100 mg/100 g could be classified as super sweet purple sweet corn lines. General combining ability (GCA) analysis conducted under Line×Tester model had identified:5 lines including UV10, UV24, UV40, UV46, UV71 had high GCA regarding marketable yield;two lines, UV12, and UV16 had high GCA on BRIX and 5 lines, UV35, UV36, UV38, UV46 and UV73, had a high GCA on AN.【Conclusion】The UV10 and UV12 lines are super sweet purple sweet corn lines that have high GCA for marketable yield and quality, respectively. These sweet purple corn inbred lines are essential in hybrid nutrient-rich fruit corn breeding programs.