Genetic analysis of leaf trichome density using mixed major gene plus polygene inheritance model in Brassica rapa ssp. chinensis

ABSTRACT

Leaf trichome is an important trait for stress-resistance breeding in Brassica crops, but its scientific evaluation and identification are rarely reported. To investigate the inheritance of leaf trichome in non-heading Chinese cabbage, two inbred lines, ‘14XS23W’ (glabrous) and ‘14XS23Y’ (hirsute), were used to generate F₁ and F₂ populations for joint analysis using a mixed major genes plus polygene inheritance model. The density of adaxial leaf trichomes was controlled by two pairs of additive-dominance-epistasis major genes plus additive-dominance polygenes. The broad-sense heritabilities of the major genes were 93.8% and 85.51%, respectively, for greenhouse and open-field conditions. However, the density of the abaxial leaf trichome was controlled by two pairs of additive-dominance-epistasis major genes plus additive dominance-epistasis polygenes. The broad-sense heritabilities of the major genes were 91.45% and 72.20%, while the polygenes were 0% and 14.5%, respectively, for greenhouse and open field environments. These results indicated that trichome density in non-heading Chinese cabbage was primarily controlled by two pairs of major genes with high heritability, implying that this trait is suitable for rapid selection in early generations.

KEYWORDS:

• Non-heading Chinese cabbage
• leaf trichome
• major gene plus polygene inheritance
• genetic analysis
• greenhouse
• field

Acknowledgements

We thank the National Soybean Improvement Center of Nanjing Agricultural University for providing the master gene + multigene genetic model analysis software that was helpful in the experiments. We are grateful for the help provided by Dr. Yupeng Pan during the revision of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All relevant data are within the paper.

Notes on contributions

Experimental design and material preparation were mainly performed by FY and MH. Data collection and analysis were mainly performed by FY, LC and MZ. FY and XZ prepared the first draft of this manuscript with the input of all the rest authors. Manuscript revision completed by XZ and MH. FY and XZ contributed equally. All authors read, edited and approved the final submission.

Additional information

Funding

This study was funded by the China Agriculture Research System of MOF and MARA (CARS-23-G22); the Shaanxi Province Key Research and Development Project (2020NY-061); and the Scientific and Technological Achievements Transformation Project of Northwest A&F University (TGZX2019-18).