Which crosses and which germplasm should go forward, and what turns a promising cross into a recognized variety?
Breeders select on yield, quality and stress traits together. MGIDI ranks genotypes on all target traits at once, and line × tester analysis estimates additive and dominance effects, which indicate whether a trait is better improved through parent selection or through heterosis. A hybrid reaches farmers only after inbred-line development, crossing, multi-location testing and official recognition; Nguyen Trung Duc works on this with the VNUA corn breeding team at the Institute of Biology and Agricultural Technology, and the same selection tools are now applied to sweetpotato and taro.
Multi-trait selection indices
The multi-trait genotype-ideotype distance index (MGIDI) ranks each genotype by its distance from an ideotype defined on all target traits.
MGIDI was used to select purple waxy corn hybrids, tropical sweet corn inbred lines and rice donors for nitrogen use efficiency; the sweet corn and rice studies also used clustering and principal component analysis.
2023 · Vietnam Journal of Science and Technology
MGIDI selects two purple waxy corn hybrids, including VNUA191
Among 25 crosses tested in spring and winter 2021 in Hanoi, the index selected THL01 (VNUA261) and THL02 (VNUA191); VNUA191 gave 12.2–13.6 t/ha of fresh ears, with thin pericarp and high anthocyanin, and was later recognized for circulation.
2024 · Ecological Genetics and Genomics
Choosing tropical sweet corn parents by index and combining ability
Clustering sorted 42 inbred lines into four groups, and MGIDI at 20% selection intensity chose eight; in 2022 testcrosses, N39 showed high general combining ability for marketable yield and N28 for soluble solids.
2025 · iScience
Multi-year selection finds rice donors for nitrogen use efficiency
Using 126 traits recorded on 300 genotypes over three years, two nitrogen levels and three locations, MGIDI ranked Cauvery, Suweon, RPW9-4 and BAM3690 as superior for nitrogen use efficiency; multi-location field trials and expression of nitrogen-assimilation genes supported Cauvery.
Gene action and parent choice
Traits controlled mainly by additive effects respond to parent selection on general combining ability; traits controlled mainly by dominance are improved through heterosis in hybrids.
Line × tester analysis estimates general and specific combining ability and the additive and dominance components of quality and yield traits in specialty sweet corn.
2026 · Journal of Crop Science and Biotechnology
In color-diverse supersweet maize, quality traits are mainly additive and yield mainly dominant
Soluble solids, pericarp thickness and anthocyanin were mainly additive (narrow-sense heritability 0.89–0.99) and fresh-ear yield mainly dominant; three elite parents, one per kernel color (Wh24, B14 and P19), gave six testcross hybrids that outyielded both checks.
Specialty corn hybrids
Five hybrids that he co-authored have been recognized for circulation since 2022; one of them, VNUA191, was among the two hybrids selected with MGIDI in the 2021 trials.
The hybrids are purple waxy, fresh-eating sweet and waxy-sweet types. All varieties →
2018 · Tap chi Nong nghiep va Phat trien Nong thon (Journal of Agriculture and Rural Development)
Multi-location testing of purple waxy hybrid VNUA141
Breeding and testing report for VNUA141 in the Red River Delta and North Central region; the hybrid was recognized for circulation in 2022.
2017 · Journal of Scientific and Engineering Research
Waxy corn hybrids from domestic and exotic germplasm
A review of VNUA's waxy maize breeding since 2003: 160 local accessions and 36 exotic germplasm sources, 1,683 inbred lines evaluated from 2009 to 2016, and the hybrids developed from them.
Sweetpotato and taro germplasm
Sweetpotato and taro germplasm is ranked with multi-trait indices on field data, and sweetpotato accessions are also fingerprinted with a small SSR marker set.
In sweetpotato, genotypes from a 50-accession panel are being evaluated for yield and carotenoid content, ranked with MGIDI and checked with SSR markers for duplicates, as part of VNUA's Strong Research Group on potential tuber crops (NCM2024-39). Thirty newly collected taro accessions were evaluated for agronomic traits and leaf blight resistance and ranked with MGIDI.
2026 · Ecological Genetics and Genomics
What AI can and cannot yet do for sweetpotato breeding
Genomic selection and genome editing remain rare in hexaploid, clonal sweetpotato; multivariate indices such as MGIDI and MTSI already rank genotypes without genomic data.