Search Results (11)

Maize is a critical crop for food, feed, and bioenergy worldwide. This study characterized the genetic diversity and population structure of 212 important inbred lines collected from the Southeast China breeding program using the Maize6H-60K single nucleotide polymorphism (SNP) array. To investigate the genetic architecture of plant height (PH) and ear height (EH), genome-wide association analysis (GWAS) was performed on this population in 2021 and 2022. Cluster analysis and population genetic structure analysis grouped the 212 maize inbred lines into 10 distinct categories. GWAS identified significant associations for PH, EH, and the EH/PH ratio. A total of 40 significant SNP (p < 8.55359 × 10⁻⁷) were detected, including nine associated with PH, with phenotypic variation explained (PVE) ranging from 3.42% to 25.92%. Additionally, 16 SNP were linked to EH, with PVE ranging from 2.49% to 38.49%, and 15 SNP were associated with the EH/PH ratio, showing PVE between 3.43% and 16.83%. Five stable SNP, identified across two or more environments, were further analyzed. Three of these SNP loci are reported for the first time in this study: two loci associated with the PH, AX-108020973, and AX-108022922, as well as one new locus, AX-108096437, which was significantly associated with the EH/PH ratio. Additionally, two other significant SNP (AX-247241325 and AX-108097244) were located within a 2 Mb range of previously identified QTL and/or related SNP. Within the 200 kb confidence intervals of these five stable SNP loci, 76 functionally annotated genes were identified. Further functional analysis indicated that 14 of these genes may play a role in regulating plant morphology, which is primarily involved in hormone synthesis, microtubule development, root growth, and cell division regulation. For instance, the homologous genes GRMZM2G375249 and GRMZM2G076029 in maize correspond to OsPEX1 in rice, a protein similar to extension proteins that are implicated in lignin biosynthesis, plant growth promotion, and the negative regulation of root growth through gibberellin-mediated pathways. The candidate gene corresponding to AX-108097244 is GRMZM2G464754; previous studies have reported its involvement in regulating EH in maize. These findings enhance the understanding of QTL associated with maize plant-type traits and provide a foundation for cloning PH, EH-related genes. Therefore, the results also support the development of functional markers for target genes and the breeding of improved maize varieties. Full article

The plant growth regulator EDAH, a combination of ethephon and diethyl aminoethyl hexanoate, has been shown to reduce maize lodging and increase crop yield under monoculture systems. However, its effectiveness under intercropping conditions remains uncertain. This study presents findings from a three-year (2020–2022) experiment that investigated the effects of EDAH application on maize and peanut yields, as well as lodging rates, within a maize/peanut intercropping system. The experimental setup included four treatments: sole maize without EDAH, sole peanut without EDAH, intercropped maize and peanut without EDAH, and intercropped maize and peanut with EDAH. Results across the three years revealed that foliar application of EDAH significantly increased maize yield by 13.6% and peanut yield by 28.3%, compared to the non-EDAH treatment in the intercropping system. Moreover, the land-equivalent ratio improved by 13.4%, indicating better land use efficiency. Maize lodging in the intercropping system with EDAH decreased by 48.7%. Additionally, EDAH-treated maize in the intercropping system exhibited a 12.1% reduction in plant height and a 27.7% reduction in ear height compared to untreated maize. The internodes 1–5 of EDAH-treated intercropped maize were 1.93–7.80 cm shorter, while the basal internode diameter increased by 3.30 to 4.90 cm. These morphological changes contributed to improved stalk strength, as evidenced by increases in stalk crush strength, rind penetration strength, and bending strength, which together improved maize lodging resistance. Collectively, these results suggest that the application of EDAH is a promising measure to reduce maize lodging and increase overall crop productivity in maize/peanut intercropping systems. Full article

Due to the high plant height, heavy ear, and easy forward tilt of millet during harvesting, the reel of a traditional combine harvester is often difficult to adapt to the special growth characteristics of millet, resulting in serious grain loss. Therefore, optimizing the design of the reel is important to improve the harvesting efficiency of millet and reduce the grain header loss. In order to determine the optimal reel speed ratio(λ), kinematics simulation experiments and analysis were carried out under different combinations of forward speed and reel revolution speed. The results showed that the supporting effect of the reel is insufficient when λ ≤ 1, and the trochoidal trajectory of the reel can provide a backward driving force when λ > 1, the optimum speed ratio of the reel should be controlled between 1.5 and 1.6. Field experiments results showed that the grain header loss rate was the lowest (0.9%) when λ = 1.6. This study provides key guidance for the adjustment of the combine harvester, effectively reducing the grain header loss rate in harvesting millet, and improving the harvesting efficiency. Full article

Wheat is one of the main food crops, the value of which lies in the high content of protein and carbohydrates in the kernel. To improve the quality of kernel processing, it is desirable that all kernels are uniform in shape and quantitative parameters. However, the kernel technological properties are affected by agricultural technology, environmental conditions and genetic characteristics, for example, even within one ear; kernels vary in size and the degree of ripening. Therefore, the aim of this work is to test the relationship between the coefficients (indices) of kernel shape variability in winter wheat lines that were pre-selected in long-term competitive variety trials and to select the best variety accession for further targeted selection to improve the uniformity of kernels. This work examined seven lines and a control variety of winter wheat grown during 2022–2023. Sampling in the field experiment was carried out randomly. The variability of quantitative traits was assessed by the analysis of variance method. It is noted that symmetrical kernels are mainly characteristic of 188h, the intermediate position is occupied by Moskovskaya 56, 150h, 152h, 171h, 184h, 187h and variety sample 151h has clearly expressed asymmetry. Index 5 of the kernel cut has a strong correlation with gluten content (r = 0.74, p = 0.05), index 4 with kernel test weight (r = 0.84, p = 0.01), index 3 with a tillering coefficient (r = 0.83, p = 0.05) and index 1 with plant height (r = 0.81, p = 0.05). An inverse relationship was found for index 2 with kernel vitreousness (r = −0.74, p = 0.05). The kernel test weight has an inverse relationship with the grain area (r = −0.71, p = 0.05). Predictive regression equations on the relationship of plant height, tillering ratio, gluten content and indices are given. While limited by its one-year duration, this study reveals intriguing correlations between grain shape parameters and economically valuable traits in wheat, offering valuable insights for high-throughput phenotyping applications in rapidly advancing agricultural technologies. This article will be useful for breeding for kernel uniformity and, consequently, for increasing the kernels in the ear and the weight of 1000 seeds. Full article

Multi-trait selection is very helpful in plant breeding programs. This technique can select genotypes for specific traits. Yield performance of maize hybrids is influenced by genotype-by-environment interactions (GEIs). This requires multi-environmental testing to identify superior hybrids. The aims of this study were to: (1) select maize hybrids within favorable traits such as grain yield and yield attributes; (2) identify genotype and environment interactions (GEIs) within maize yield; (3) evaluate maize hybrids adaptability to four different locations in West Java; and (4) identify a representative environment for testing and developing new maize hybrids. Twenty-two maize hybrids were evaluated using a randomized block design repeated three times in each environment. The genotype by traits (GT) biplot showed that G3 maize hybrid was superior to ear weight (EW), ear weight without corn husk (EwoH), ear weight per plot (EWP), plant height (PH), ear diameter (ED), and 1000 seed weight (OSW) traits. The G22 maize hybrid was superior to ear weight without corn husk per plot (EwoP), ratio seed weight and ear weight without corn husk (RSEW), grain yield per ha (Y), seed weight (SW), and seed weight per plot (SWP) traits. Combined analysis of variance showed that genotype (G), environment (E), and their interactions (GEIs) had a significant effect on yield (p < 0.01) with contributions of 85.63%, 2.24%, and 12.13%, respectively. The combined stability measurement results and the GGE biplot reveal that G2 is a stable high-yield hybrid, while G4 and G16 are unstable high-yield hybrids. The most representative environment is Arjasari, with the sole-cropping system (ARJ M). This study reveals that the resulting maize hybrid can be useful as a substitute for commercial hybrids currently used. The stable high yield of maize hybrids can be recommended as new varieties with wide adaptation, while unstable high-yield hybrids can be recommended as varieties adapted to specific environments. Full article

This study was undertaken to identify oat (Avena sativa L.) varieties optimal for cultivation in the Jiuquan region, China, in 2021. A selection of 27 domestic and international oat varieties were analyzed, considering ten key agronomic traits, including plant height, stem diameter, spike length, leaf width, and yield. Employing methods such as cluster analysis, principal component analysis, and grey correlation degree, a comprehensive evaluation was conducted. The principal component analysis distilled the ten indicators to three core components. The most influential factors in the first principal component were plant height, ear length, and hay yield, while leaf length and leaf area index were the highest contributors to the second component. The stem-to-leaf ratio emerged as the principal indicator in the third component. The cluster analysis resulted in the classification of the 27 oat varieties into 3 categories. Following a comprehensive evaluation through the grey correlation degree and principal component analysis methodologies, we found that the oat varieties Sweety 1, Fuyan 1, Dingyan 2, Baler, Quebec, and Longyan 2 received the highest scores. These varieties, hence, appear to be the most suitable for cultivation and promotion in the Jiuquan region. This study thus provides invaluable insights into oat cultivation practices, offering guidance for farmers, agricultural policymakers, and future research in the field. Full article

Maize growth in narrow rows provides a more uniform spatial arrangement, but it does not always lead to increasing yield. A four-year study was conducted to investigate the effect of row spacing on silage maize growth and yield during the growing season and at harvest time. A field experiment with conventional (0.70 m) and narrow rows (0.35 m) at a plant density of 92,000 plants ha⁻¹ was evaluated in the years 2011–2014, and the interaction of row spacing × plant density (92,000 and 110,000 plants ha⁻¹) was tested in 2013–2014. The narrow rows clearly demonstrated potential to support plant height and weight development, together with a higher stalk proportion, at around two months after seeding. However, these contrasts were lost in the later stages and at harvest time. Some potential for non-significantly higher dry matter yield (4.6–10.8%) was shown in the narrow rows in three years of the experiment, in association with lower losses in plant numbers, when compared to conventional row spacing. The potential of yield improvement in the narrow rows showed relationships with weather conditions during the second half of the growing season. In summary, under the growing conditions of the study region, narrow row spacing significantly promoted early plant development, but these effects did not persist until harvest, thus resulting in only limited success in yield improvement. Full article

Ear height (EH) and ear–plant height ratio (ER) are important agronomic traits in maize that directly affect nutrient utilization efficiency and lodging resistance and ultimately relate to maize yield. However, challenges in executing large-scale EH and ER measurements severely limit maize breeding programs. In this paper, we propose a novel, simple method for field monitoring of EH and ER based on the relationship between ear position and vertical leaf area profile. The vertical leaf area profile was estimated from Terrestrial Laser Scanner (TLS) and Drone Laser Scanner (DLS) data by applying the voxel-based point cloud method. The method was validated using two years of data collected from 128 field plots. The main factors affecting the accuracy were investigated, including the LiDAR platform, voxel size, and point cloud density. The EH using TLS data yielded R² = 0.59 and RMSE = 16.90 cm for 2019, R² = 0.39 and RMSE = 18.40 cm for 2021. In contrast, the EH using DLS data had an R² = 0.54 and RMSE = 18.00 cm for 2019, R² = 0.46 and RMSE = 26.50 cm for 2021 when the planting density was 67,500 plants/ha and below. The ER estimated using 2019 TLS data has R² = 0.45 and RMSE = 0.06. In summary, this paper proposed a simple method for measuring maize EH and ER in the field, the results will also offer insights into the structure-related traits of maize cultivars, further aiding selection in molecular breeding. Full article

Perennial groundcover (PGC) merges scalable soil and water conservation with high-yielding row crops, enhancing ecosystem services of annual grain crop production. However, ineffective groundcover suppression increases competition between the groundcover and row crop, reducing row crop grain yield. The objective of this study was to assess the effectiveness of three Kentucky bluegrass (KBG) groundcover suppression methods each at narrow and wide widths on maize (Zea mays L.) growth and development in evenly spaced PGC, compared to alternating PGC swards and a no-PGC conventional tillage control. Suppression methods for evenly spaced PGC included two different strip tillage implements, completing either shallow or deep soil fracture, for mechanical suppression and a banded sprayer for no-tillage chemical suppression. We measured weekly for maize plant height, phenological stage of development, reflected red:far-red (R:FR) ratio, early vegetative and final plant density, grain and stover yield, yield components of kernel rows ear⁻¹, kernels row⁻¹, kernels ear⁻¹, ear length, kernel weight, grass frequency, and weed community. In 2020, maize grain yield in the alternating PGC swards (11.38 Mg ha⁻¹) was similar to the control (12.78 Mg ha⁻¹) and greater than in the evenly spaced groundcover (9.62 Mg ha⁻¹). Maize grain yield was similar for systems in 2021 (7.41 Mg ha⁻¹), due to drought and high coefficient of variation. Weed community was similar for systems in both years. A maize competition response was observed for both suppression widths across methods. Groundcover dormancy may be needed in conjunction with effective chemical and/or mechanical groundcover suppression to support maize production in PGC. Full article

Global warming increases the risk of high-temperature injury to maize. Inter- and mixed-cropping of maize varieties with different genotypes is one way to effectively alleviate the high-temperature injury during the flowering period. However, the mitigation effect of different varieties and intercropping modes on high-temperature injury is still unclear. Based on previous years of field production, Denghai 605, which is more sensitive to high temperatures during the flowering period, was determined as the main test variety, and Zhengdan 958, Dedan 5, Weike 702, and Xianyu 335, which have great genotypic differences, were used as auxiliary varieties. The main test varieties and auxiliary varieties were intercropped and mixed cropped, respectively. Plant height, ear height, leaf area index, population light transmittance, ear characteristics, and yield were measured, and the land equivalent ratio (LER) was calculated. The plant height of Denghai 605 intercropped with Zhengdan 958 and Dedan 5 and mixed with Weike 702 and Xianyu 335 decreased significantly. The population light transmittance of the bottom or middle layer in Denghai 605 increased significantly when intercropped with other varieties. The grain number per ear increased significantly under inter- and mixed cropping with Zhengdan 958 and Weike 702. Except under intercropping with Dedan 5, the yield of Denghai 605 increased significantly, by 8.8–28.0%, under inter- and mixed cropping. Under intercropping with Zhengdan 958 and inter- and mixed cropping with Weike 702 and Xianyu 335, respectively, the group land equivalent ratio was greater than 1.1, indicating that under the combination of these varieties, inter- and mixed cropping effectively reduced the impact of high temperatures during flowering. Full article

In the field, maize flowering time and height traits are closely linked with yield, planting density, lodging resistance, and grain fill. To explore the genetic basis of flowering time and height traits in maize, we investigated six related traits, namely, days to anthesis (AD), days to silking (SD), the anthesis–silking interval (ASI), plant height (PH), ear height (EH), and the EH/PH ratio (ER) in two locations for two years based on two doubled haploid (DH) populations. Based on the two high-density genetic linkage maps, 12 and 22 quantitative trait loci (QTL) were identified, respectively, for flowering time and height-related traits. Of these, ten QTLs had overlapping confidence intervals between the two populations and were integrated into three consensus QTLs (qFT_YZ1a, qHT_YZ5a, and qHT_YZ7a). Of these, qFT_YZ1a, conferring flowering time, is located at 221.1–277.0 Mb on chromosome 1 and explained 10.0–12.5% of the AD and SD variation, and qHT_YZ5a, conferring height traits, is located at 147.4–217.3 Mb on chromosome 5 and explained 11.6–15.3% of the PH and EH variation. These consensus QTLs, in addition to the other repeatedly detected QTLs, provide useful information for further genetic studies and variety improvements in flowering time and height-related traits. Full article