Spatial variation of maize height morphological traits for the same cultivars at a large agroecological scale
Introduction
Maize (Zea mays L.) is the most productive food crop worldwide and is expected to play a crucial role in ensuring food security and clean energy production in the future (Lorenz et al., 2010; FAO, 2016). In maize breeding programs, many different traits normally need to be considered. Among these, plant morphology is a set of important traits, optimizing the maize plant morphology is conducive to the improvement of maize population structure and thereby to the increase of yield (Li et al., 2014; Liu et al., 2017).
As the bases of maize ideotype, maize height morphological traits including plant height, ear height, and ear ratio (i.e. percentage of ear height to plant height) are associated with plant lodging in the field (Novacek et al., 2013; Liu et al., 2017; Xue et al., 2017). Because the excessive high plant and ear height will cause high risk of lodging due to the higher centre of gravity height (the balance point of the above ground plant) (Liu et al., 2017). Therefore, the height morphological traits have long been the concern of breeders and agronomists. On the other hand, the height morphological traits are tightly linked with maize aboveground dry matter (DM) and grain yield (Khush, 1999), especially the plant height can be used as a single factor to measure the vegetative growth and potential yield of maize (Sharma et al., 2016). Additionally, changes in maize height morphological traits due to cultivar replacement have been shown to vary with the region. For example, Ma et al. (2014a) observed a weak increase in plant height and a decrease in ear height and ear ratio in maize cultivars released between the 1950s and 2010s in China. Whereas it was conversely found that maize plant height was basically unchanged, while ear height decreased, along with long-term commercial hybrid maize selection in the United States (Duvick et al., 2004).
The differences in maize plant height and ear height have been shown to be caused by differences in both the total internode number and internode length, and differences in both the internode number and internode length below the primary ear, respectively (Zhu et al., 2013; Chen et al., 2018). For some hybrids, a significant difference in ear height is caused by longer internodes, especially between the sixth and seventh internodes and between the seventh and eighth internodes (Chen et al., 2018). For maize cultivars released from the 1950s to the 2010s in China, the internode number per plant was not found to change significantly with cultivar replacement, the lengths of the first to eighth internodes below the ear slightly decreased, and the lengths of the ninth to sixteenth internodes increased (Ma et al., 2014b).
Maize is widely cultivated throughout an extremely wide range of natural environments within the latitudes of approximately 50 °N to 45 °S and at elevations from 0 to over 3800 m above sea level (Leff et al., 2004; Ramirez-Cabral et al., 2017). However, maize height morphological traits greatly differ in different environments (Pecina-Martínez et al., 2009; Barrero Farfan et al., 2013). Many factors contribute to interregional differences in maize height morphological traits, including genotype (Subedi and Ma, 2005; Ma et al., 2014b) and agronomic practices such as planting density (Gou et al., 2017), fertilization (Elawad, 2015), tillage practices (Boomsma et al., 2010), and soil moisture regime (Robertson, 1994). However, additionally, climatic factors contribute to interregional differences in maize height morphological traits. For example, John Sunoj et al. (2016) reported that plant height decreased with decreasing diurnal temperature range for the same daily mean temperature. Yang et al. (2014) found that maize plant height decreased by about 10 % in a DIP treatment (a combination of photoperiod and temperature treatment). Furthermore, another study on sowing dates showed that the daily mean temperature and mean day length were the main factors that affected the plant height and ear height (Huo and Gao, 1996). Moreover, shading experiments indicated that lower solar radiation resulted in a decrease in plant and ear height (Zhang et al., 2006; Cui et al., 2012). However, in general, most previous studies were conducted in limited areas or controlled environments, and the results varied due to the use of various genotypes and experimental treatments. Therefore, there is a lack of systematic studies on maize height morphological traits across a large agroecological span.
As maize height morphological traits and their components have high heritability and strong heterosis and it is easy to obtain accurate phenotypic data compared with other complex traits, these traits are often used as some of the model traits for genetic research on maize (Peiffer et al., 2014; Wang et al., 2016; Zhou et al., 2018), such as heterosis and quantitative trait loci (QTL) analysis (Zhu et al., 2013; Muttoni et al., 2013; Li et al., 2014). Maize is widely cultivated in China where ecological and climatic conditions vary more dramatically (Li and Wang, 2010; Liu et al., 2015) than other countries where maize production is relatively concentrated, such as the United States (Leff et al., 2004).
Therefore, in the present study, five commonly used maize cultivars were planted in 23 sites covering the four largest maize-growing regions in China to study how the maize height morphological traits adapt to different climatic conditions at a large regional scale. The objectives of this study were to (i) systematically identify the variation of maize height morphological traits for the same cultivars and the differences in height morphological traits between cultivars over a wide range of environmental conditions; (ii) determine the main climatic factors influencing height morphological traits; (iii) quantify the relationship between the height morphological traits and their components; and (iv) quantify relationships between plant height, DM, and grain yield. The results of this study are helpful for understanding the ecological adaptability of maize morphological traits and providing support for research on the genetic and molecular mechanisms of differences in maize plant height traits in a larger range of natural environments.
Section snippets
Site description and experimental design
Field experiments were conducted in four consecutive years from 2013 to 2016 at 23 sites between latitudes of 26°30′ and 46°45′ N under the same planting density. These sites covered the four largest maize-growing regions in China, namely the Northwestern maize region (NW), Northern spring maize region (NM), Huanghuaihai maize region (HM), and the Southwestern maize region (SW) (Fig. 1). The NM is the largest maize-growing region in China. In this region, the annual ≥10 °C accumulated
Differences in height morphological traits across all sites
The mean plant heights of DH11, NH101, XY335, ZD958, and ZD909 were 305.3, 301.7, 301.5, 262.7, and 259.6 cm, respectively, across all sites and planting years (Table 2). The results of ANOVA showed that the plant height increased in the order of ZD909 < ZD958 < XY335 < NH101 < DH11 in each planting year and across all planting years. The plant heights of DH11 (which was the highest of all the five cultivars), NH101, and XY335 were significantly higher than those of ZD958 and ZD909 (P < 0.05),
Maize height morphological traits across a large environmental span
The height morphological traits of maize vary in different environments, which reflects the plant's environmental adaptation (Barrero Farfan et al., 2013). In this study, the ranges of plant height, ear height, and ear ratio for the same cultivars changed from 124.0 to 162.2 cm, from 81.9 to 99.5 cm, and from 0.16 to 0.23, respectively, across all sites and planting years (Table 2). These ranges are higher than those reported in previous studies (Beyene et al., 2006; Pecina-Martínez et al., 2009
Conclusions
The maize main height morphological traits showed wide ranges for the same cultivars planted over a large spatial scale within the latitudes of 26°30′ to 46°45′ N and longitudes of 81°19′ to 130°16′ E due to varied environmental conditions among different planting regions. Compared with the aboveground internode number and internode number below the primary ear, the mean internode length and mean internode length below the primary ear were found to be the main contributors to the differences in
CRediT authorship contribution statement
Wanmao Liu: Conceptualization, Methodology, Investigation, Writing - original draft. Guangzhou Liu: Investigation, Writing - original draft. Yunshan Yang: Formal analysis, Investigation. Xiaoxia Guo: Formal analysis, Investigation. Bo Ming: Software, Investigation. Ruizhi Xie: Methodology, Investigation. Yuee Liu: Visualization, Investigation. Keru Wang: Visualization, Investigation. Peng Hou: Conceptualization, Resources, Investigation, Writing - review & editing. Shaokun Li:
Declaration of Competing Interest
The authors report no declarations of interest.
Acknowledgments
We gratefully acknowledge all researchers in the experimental stations for collecting the data. This research was supported by the National Key Research and Development Program of China (2016YFD0300110, 2016YFD0300101), the National Natural Science Foundation of China (31871558, 31501266, 31371575), and the National Basic Research Program of China (973, Program: 2015CB150401).
References (53)
- et al.
A multi-environment trial analysis shows slight grain yield improvement in Texas commercial maize
Field Crops Res.
(2013) - et al.
Maize grain yield responses to plant height variability resulting from crop rotation and tillage system in a long-term experiment
Soil Till Res.
(2010) - et al.
Grain yields in relation to N requirement: optimizing nitrogen management for spring maize grown in China
Field Crops Res.
(2012) - et al.
Phenological responses of maize to changes in environment when grown at different latitudes in China
Field Crops Res.
(2013) - et al.
Canopy characteristics of high-yield maize with yield potential of 22.5 Mg ha−1
Field Crops Res.
(2017) - et al.
Changes in the morphological traits of maize genotypes in China between the 1950s and 2000s
Eur. J. Agron.
(2014) Relationships between internode elongation, plant height and leaf appearance in maize
Field Crops Res.
(1994)- et al.
Use of corn height measured with an acoustic sensor improves yield estimation with ground based active optical sensors
Comput. Electron. Agric.
(2016) - et al.
Heterotic loci identified for plant height and ear height using two CSSLs test populations in maize
J. Integr. Agric.
(2016) - et al.
Adjusting maize plant density to different climatic conditions across a large longitudinal distance in China
Field Crops Res.
(2017)
Research progress on reduced lodging of high-yield and -density maize
J. Integr. Agric.
Temperature DIP at the beginning of the photoperiod reduces plant height but not seed yield of maize grown in controlled environments
Ind. Crops Prod.
QTL Mapping for stalk related traits in maize (Zea mays L.) under different densities
J. Integr. Agric.
Variability among maize hybrids differing in canopy architecture for above-ground dry matter and grain yield
Maydica
"Production, Breeding and Process of Maize in China." Handbook of Maize: Its Biology
Genetic diversity in traditional Ethiopian highland maize accessions assessed by AFLP markers and morphological traits
Biodivers. Conserv.
The effects of varying chromosome arm dosage on maize plant morphogenesis
Genetics
Proteomic analysis reveals that auxin homeostasis influences the eighth internode length heterosis in maize (Zea mays)
Sci. Rep.-UK
Interrelationships among plant height, number of leaves, and flowering dates in maize1
Agron. J.
Effects of shading on stalks morphology, structure and lodging of summer maize in field
Sci. Agric. Sin.
Leafy reduced-stature maize hybrids for short-season environments
Crop Sci.
Long-term selection in a commercial hybrid maize breeding program
Plant Breed. Rev.
Growth and Production of Maize (zea Mays l.) As Affected by Water Treatment, Organic and Inorganic Fertilizers
Relative utility of agronomic, phenological, and morphological traits for assessing genotype-by-environment interaction in maize inbreds
Crop Sci.
FAOSTAT—Agriculture Database
By-plant prediction of corn forage biomass and nitrogen uptake at various growth stages using remote sensing and plant height
Agron. J.
Cited by (10)
Uncovering microsatellite markers associated with agronomic traits of South Sudan landrace maize
2023, Genes and Genomics