Junfeng Hou¹ , Junmei Zhang² , Fei Bao¹ , Ping Zhang¹ , Hailiang Han¹ , Heping Tan¹ , Bin Chen¹ , Fucheng Zhao¹

1 Institute of Maize and Featured Upland Crops, Zhejiang Academy of Agricultural Sciences, Dongyang, 322100, Zhejiang, China
2 Agricultural Industry Service Center of Qingyuan County, Qingyuan, 323899, Zhejiang, China
Author    Correspondence author
Molecular Plant Breeding, 2024, Vol. 15, No. 4   doi: 10.5376/mpb.2024.15.0020
Received: 10 Jul., 2024    Accepted: 15 Aug., 2024    Published: 30 Aug., 2024

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Hou J., Zhang J., Bao F., Zhang P., Han H., Tan H., Chen B., and Zhao F., 2024, The contribution of exotic varieties to maize genetic improvement, Molecular Plant Breeding, 15(4): 198-208 (doi: 10.5376/mpb.2024.15.0020)

Maize (Zea mays L.) is one of the most important staple crops globally, providing essential food and energy resources for millions of people. The genetic improvement of maize has been a focal point of agricultural research, aiming to enhance yield, resilience, and adaptability to various environmental conditions. The introduction of exotic maize lines into adapted germplasm has shown significant potential in increasing genetic variability and improving agronomic traits. For instance, testcrosses of backcross-derived lines exhibited substantial yield improvements, with some lines producing up to 1 056 kg/ha more grain than the control. RNA-sequencing of diverse maize lines revealed extensive genetic and transcriptomic diversity, identifying novel transcripts that contribute to heterosis. Screening of elite exotic inbreds demonstrated that certain tropical lines performed well in temperate environments, suggesting their utility in broadening the genetic base of U.S. maize. Additionally, molecular marker studies confirmed high levels of polymorphism and genetic diversity in tropical maize germplasm. Adaptation efforts have successfully integrated tropical germplasm into temperate breeding programs, enhancing genetic gains. The findings underscore the value of exotic germplasm in maize breeding programs. The integration of exotic alleles has not only expanded the genetic base but also led to the development of high-yielding hybrids with improved agronomic traits. These results highlight the importance of utilizing diverse genetic resources to achieve sustainable genetic improvement in maize.

Maize (Zea mays L.); Genetic diversity; Exotic germplasm; Yield improvement; Tropical maize; Temperate breeding