Developing the next generation of diverse and healthier maize cultivars tolerant to climate changes
Maize (Zea mays L.) average yields per hectare have significantly increased in the past 80 years. However, the variability of these yields across years has also significantly increased in the past 40 years making newer and genetically narrow-based hybrids, on average, less stable and more susceptible to climate changes. The objective of this research was to develop new sources of short-season inbred lines carrying unique alleles to grow maize hybrids under challenging environments. The North Dakota State University (NDSU) maize germplasm enhancement program has recently developed 10 new and unique exotic short-season populations partially derived from Argentina, Brazil, Chile, Cuba, Mexico, Saint Croix, and the USA. These germplasm sources were created recombining top early-generation NDSU EarlyGEM lines that were extensively tested in hybrid trials for general combining ability of several traits. Results have shown that germplasm carrying unique alleles can break environmental margins for maize production. Unfortunately, maize breeding programs tend to be located in ideal crop production areas instead of exploiting marginal environments for the development of more stable products. The NDSU EarlyGEM program is a successful example of tropical and late-temperate maize germplasm adaptation into short-season environments in order to increase the genetic diversity on farms. However, public sector applied maize breeding programs continue to disappear across the USA and abroad because of changes in research emphasis. Long-term germplasm adaptation and improvement programs carrying unique alleles will be essential in the development of the next generation of healthier cultivars tolerant to climate changes.
KeywordsCultivars Climate change Healthier maize NDSU EarlyGEM Zea mays L.
The North Dakota Corn Utilization Council and the USDA–GEM program have supported the creation of the first generation NDSU EarlyGEM lines and populations to increase the genetic diversity of US northern maize hybrids.
- Buckler ES, Holland JB, Bradbury PJ, Acharya CB, Brown PJ, Browne C, Ersoz E, Flint-Garcia S, Garcia A, Glaubitz JC, Goodman MM, Harjes C, Guill K, Kroon DE, Larsson S, Lepak NK, Li H, Mitchell SE, Pressoir G, Peiffer JA, Rosas MO, Rocherford TR, Romay MC, Romero S, Salvo S, Villeda HS, da Silva HS, Sun Q, Tian F, Upadyayula N, Ware D, Yates H, Yu J, Zhang Z, Kresovich S, McMullen MD (2009) The genetic architecture of maize flowering time. Science 325:714–718PubMedCrossRefGoogle Scholar
- Carena MJ 2012. Challenges and opportunities for developing maize cultivars in the public sector. Euphytica (in press)Google Scholar
- Carena MJ, Hallauer AR (2001a) Expression of heterosis in leaming and midland yellow dent populations. J Iowa Acad Sci 108:73–78Google Scholar
- Carena MJ, Hallauer AR (2001b) Response to inbred progeny recurrent selection in leaming and midland yellow dent populations. Maydica 46:1–10Google Scholar
- Carena MJ, Wicks ZW III (2006a) Maize early maturing hybrids: an exploitation of US temperate public genetic diversity in reserve. Maydica 51:201–208Google Scholar
- Carena MJ, Wicks ZW III (2006b) Maize early maturing hybrids: an exploitation of US temperate public genetic diversity in reserve. Maydica 51:201–208Google Scholar
- Carena MJ, Bergman G, Riveland N, Eriksmoen E, Halvorson M (2009b) Breeding maize for higher yield and quality under drought stress. Maydica 54:287–296Google Scholar
- Cochran WG, Cox GM (1957) Experimental design, 2nd edn. Wiley, New YorkGoogle Scholar
- Goodman MM (1985) Exotic maize germplasm: status, prospects, and remedies. Iowa state J Res 59:497–527Google Scholar
- Goodman MM (1999) Broadening the genetic diversity in maize breeding by use of exotic germplasm. In: Coors JG, Pandey S (eds) The genetics and exploitation of heterosis in crops. ASA-CSSA-SSSA, Madison, pp 139–148Google Scholar
- Hallauer AR (1978) Potential of exotic germplasm for maize improvement. In: Walsen DB (ed) Maize breeding and genetics. John Wiley and Sons, New YorkGoogle Scholar
- Hallauer AR, Carena MJ (2009) Maize breeding. In: Carena MJ (ed) Handbook of plant breeding: cereal breeding. Springer, New YorkGoogle Scholar
- Hallauer AR, Carena MJ, Miranda Fo JB (2010) Quantitative genetics in maize breeding, 3rd edn. Springer, New YorkGoogle Scholar
- Milton DJ (1970) Plant introduction of maize as a source of oil and unusual fatty acid composition. J Agric Food Chem 18:1970Google Scholar
- Moll RH, Lonnquist JH, Fortuno JV, Johnson EJ (1965) The relationship of heterosis and genetic divergence in maize. Genetics 42:139–144Google Scholar
- Rinke EH, Sentz JC (1962) Moving corn belt dent germplasm northward. Minnesota Agric Exp Stn 110:53Google Scholar
- Sevilla R, Salhuana W (1997) General description of the plan and execution of latin American maize project (LAMP). In: Salhuana W, Sevilla R, Eberhart SA (eds) LAMP final report 1997. Wiley and sons, New York, pp 1–35Google Scholar
- Sharma S, Carena MJ (2012) NDSU EarlyGEM: increasing the genetic diversity of northern US hybrids through the development of unique exotic elite lines. Maydica (in press)Google Scholar